Re: Perl regular expression for implementing infix expression parser?
Well, I'm thinking of a simple syntax tree that would fit on a one-liner? For
the first cut, I think I'll ignore unary operators and just accommodate numeric
integer literals for addition, subtraction, multiplication and division.
Later we can add variables, unary operators, functions like log10, sin, cos
etc...
See Recursive descent parser - Wikipedia, the free encyclopedia
e for expressionf for factorpm for plus or minusmd for multiply divide
n for numeric literal
here is my attempt so far (that does not work):
.! perl -pe 'BEGIN{ $n=qr{\d+}x; $pm=qr{[-\+]}x; $md=qr{[/\*]}x;
$e=qr{$t($pm$t)?}x; $f=qr{$n|\($e\)}x; $t=qr{$f($md$f)?}} s/($t)=(
*)/"$1=".eval($1)/ge'
Here is my sample data55-23=
It seems to ignore the 55.ThanksSiegfried
On Sunday, August 14, 2016 4:26 AM, David Mertens
<dcmertens.p...@gmail.com> wrote:
Hello siegried,
This is a fun question! In fact, v5.10 introduced "recursive subpatterns" into
the regex lexicon, so using v5.10 or later, it is possible to implement (rather
arcane) recursive descent regexes without resorting to eval-based tricks like
what you have.
But before diving in, a few questions are in order to make sure we're working
on the right problem. Are you looking for something to cram into a one-liner?
(Do you have a character limit for your one-liner?) Are you open to solving
this with a combination of for-loops and regexes, or do you want a purely
regex-based approach? Are you trying to write something that merely validates
that an expression as valid mathematics, or do you want to build an abstract
syntax tree? Are you interested in using modules from CPAN or rolling your own?
Finally, if your answer to all of these is, "I'm just curious!", then you can
expect to get a very wide range of answers, not just regex-based.
Thanks! Looking forward to the fun!
David
On Sat, Aug 13, 2016 at 3:45 PM, Richard Heintze via beginners
<beginners@perl.org> wrote:
I this perl one liner for evaluating infix expressions in VI and emacs/VI
emulator mode:
.! perl -MPOSIX -pe ' BEGIN{ $np = qr{ \( (?: (?> [^()]+ ) | (??{ $np }) )*
\) }x;$funpat = qr/$np/;} s/($funpat)=($funpat|(")[^\"]*
(")|[0-9\.]+)/"$1=$3".eval($1) ."$4"/ge'
That $np is from the camel book and it is a regular expression that parses
nested sets of parentheses and then my replace command evaluates the arithmetic
expression.
Since perl accommodates recursive regular expressions, it ought to be possible
to implement a recursive decent parser.
Can someone help me enhance the above code so that instead of just blindly
looking for balanced parenthesis, the regular expression will recognize (match)
this:
5+8*(2+8/(3+2))*(2+22/3)=()Thankssiegfried
--
"Debugging is twice as hard as writing the code in the first place.
Therefore, if you write the code as cleverly as possible, you are,
by definition, not smart enough to debug it." -- Brian Kernighan
Perl regular expression for implementing infix expression parser?
I this perl one liner for evaluating infix expressions in VI and emacs/VI
emulator mode:
.! perl -MPOSIX -pe ' BEGIN{ $np = qr{ \( (?: (?> [^()]+ ) | (??{ $np }) )*
\) }x;$funpat = qr/$np/;}
s/($funpat)=($funpat|(")[^\"]*(")|[0-9\.]+)/"$1=$3".eval($1)."$4"/ge'
That $np is from the camel book and it is a regular expression that parses
nested sets of parentheses and then my replace command evaluates the arithmetic
expression.
Since perl accommodates recursive regular expressions, it ought to be possible
to implement a recursive decent parser.
Can someone help me enhance the above code so that instead of just blindly
looking for balanced parenthesis, the regular expression will recognize (match)
this:
5+8*(2+8/(3+2))*(2+22/3)=()Thankssiegfried
Wanted: Help performing Date-Time Arithmetic using emacs/vi and perl
I just love using viper mode in emacs to execute perl:
.! perl -MPOSIX -pe ' BEGIN{ $np = qr{ \( (?: (?> [^()]+ ) | (??{ $np }) )* \)
}x;$funpat = qr/$np/;} s/($funpat)=(.*)$/"$1=$3".eval($1)."$4"/ge'
This command searches for a balanced set of parens (from the camel book)
followed by an equal sign followed by any trailing garbage and evaluates the
expression inside the balanced parans.
so if you type
(4*atan(1))=gobblygook
and then execute the above VI/Ex command you get:
4*atan(1))=3.14159265358979
Here is my failed attempt to do date arithmetic:
(use Date::Calc ( ":all" ); use Date::Manip; my ( $date, $yy, $dd, $mm ); $date
= scalar localtime( ( time() - ( 24 * 60 * 60 ) ) ); $date)=""
Can someone help me figure out how to use the eval function in my perl
one-liner to evaluate date time arithmetic?
Thanks,Siegfried
Re: Removing text
Hi!
On 18 May 2015, at 18:27, Richard Taubo o...@bergersen.no wrote:
Hi,
and thanks to Shawn H Corey, Jing Yu.
I see that I have not been specific enough.
(And sorry for the top posting).
The full (bash) script with perl parts looks like this:
[$] top_return=$(top -n1 | head -5)
[$] io_return=$(printf %s\n $top_return | grep ^Cpu(s))
[$] io_all=$(printf %s $io_return | awk '{ printf $9 }' | perl -pe
's/\%st//')
[$] printf %s\n $io_all
Returns = 0.0%st(would want it to be: 0.0 without the '%st'
part).
This kind of works:
[$] io_all=$(printf %s $io_return | awk '{ printf $9 }' | perl -pe
's/\%//')
[$] printf %s\n $io_all
Returns = 0.0st (without the % sign)
This too:
[$] io_all=$(printf %s $io_return | awk '{ printf $9 }' | perl -pe
's/st//')
[$] printf %s\n $io_all
Returns = 0.0% (without the st characters)
BUT when i search and replace for %st (as described above), I can’t
get it to work.
Thanks for any feedback, and thanks again for the answers I have received. :-)
In the end, I ended up with two separate perl commands.
One removing the % part of the text, the other the st part of the text:
io_all=$(printf %s\n $cp_return | awk '{ printf $9 }' | perl -pe 's/%//' |
perl -pe 's/st//')
Returns = 0.0 (without the %st characters)
That works fine, but looks a little clunky, are there perhaps other ways to
unite the two
perl commands?
Thanks!
Richard Taubo
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Removing text
Hi! Trying to remove the literal text %st from the command line return value: 0.0%st as in: [$] printf 0.0%st | perl -pe 's/\%st//' I have also tried: [$] printf 0.0%st | perl -pe 's/\Q%st\E//' Neither works. Would be happy if someone had any input here! :-) Thanks! Richard Taubo -- To unsubscribe, e-mail: beginners-unsubscr...@perl.org For additional commands, e-mail: beginners-h...@perl.org http://learn.perl.org/
Re: Removing text
Hi,
and thanks to Shawn H Corey, Jing Yu.
I see that I have not been specific enough.
(And sorry for the top posting).
The full (bash) script with perl parts looks like this:
[$] top_return=$(top -n1 | head -5)
[$] io_return=$(printf %s\n $top_return | grep ^Cpu(s))
[$] io_all=$(printf %s $io_return | awk '{ printf $9 }' | perl -pe
's/\%st//')
[$] printf %s\n $io_all
Returns = 0.0%st (would want it to be: 0.0 without the '%st'
part).
This kind of works:
[$] io_all=$(printf %s $io_return | awk '{ printf $9 }' | perl -pe
's/\%//')
[$] printf %s\n $io_all
Returns = 0.0st (without the % sign)
This too:
[$] io_all=$(printf %s $io_return | awk '{ printf $9 }' | perl -pe
's/st//')
[$] printf %s\n $io_all
Returns = 0.0% (without the st characters)
BUT when i search and replace for %st (as described above), I can’t
get it to work.
Thanks for any feedback, and thanks again for the answers I have received. :-)
Best regards,
Richard Taubo
On 18 May 2015, at 17:52, Shawn H Corey shawnhco...@gmail.com wrote:
On Mon, 18 May 2015 17:32:03 +0200
Richard Taubo o...@bergersen.no wrote:
Hi!
Trying to remove the literal text %st from the command line return
value: 0.0%st as in:
[$] printf 0.0%st | perl -pe 's/\%st//'
I have also tried:
[$] printf 0.0%st | perl -pe 's/\Q%st\E//'
Neither works.
Would be happy if someone had any input here! :-)
Thanks!
Richard Taubo
I'm not sure what you're trying to do but if you want a percent sign in
a printf specification, use two of them.
printf Sale: %d%% off, $percentage_off;
See `perldoc -f sprintf`
http://perldoc.perl.org/functions/sprintf.html
And:
On 18 May 2015, at 17:49, Jing Yu logus...@googlemail.com wrote:
Hi Richard,
When you
printf 0.0%st”
in the command line, it prints
0.0t
And that is the string piped to perl. This is perhaps why you didn’t succeed.
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RE: which module to read configuration file?
There is code available from my wizard at
http://www.rtbaileyphd.com/perlwizard that is doing something fairly similar
to what you described. Use PerlWizard to generate a simple test program,
run it once, and then examine the contents of the pwiz subirectory, which is
where the config files go. These are used in conjunction with Getopt::Long
as well.
Best Regards,
R. T. Bailey
-Original Message-
From: lee [mailto:l...@yun.yagibdah.de]
Sent: Saturday, August 30, 2014 12:09 PM
To: beginners@perl.org
Subject: Re: which module to read configuration file?
lee mailto:l...@yun.yagibdah.de l...@yun.yagibdah.de writes:
Hi,
is there a module available to read configuration files which are like
this:
arbitrary_denominator-00 | alternate-denominator-00 |
alternate-denominator-01 [| ...] {
itemA = some string
itemB = some integer
itemC = some float
itemD = some CSV
}
Following-up my own question: I found [1] which appears to come close to
what I'm looking for. Of course, I'd still love to hear your ideas :)
[1]: https://metacpan.org/pod/Config::JSON
https://metacpan.org/pod/Config::JSON
--
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http://learn.perl.org/ http://learn.perl.org/
PerlWizard - A free wizard for automatic Perl software code generation using simple forms
Summary. PerlWizard http://www.rtbaileyphd.com/perlwizard quickly generates front ends for user-friendly Perl scripts for Unix and Windows, with emphasis on the user interface, managing defaults files, and providing help. The generated user interface supplies defaults for unentered options, validates options, and records options for use as defaults on subsequent runs of the generated scripts. This makes PerlWizard scripts much more interactive and friendly than typical command line programs. Once PerlWizard generates the front end, the programmer just needs to go to the bottom of the generated code and start writing. No need to worry about how to set up Getopt::Long http://perldoc.perl.org/Getopt/Long.html calls, initialization files, built-in help, log files, etc. PerlWizard is available at http://www.rtbaileyphd.com/perlwizard. Basically, you just need to fill out a few simple forms, click a few buttons, and you can quickly jump into coding the guts of your script without bothering with all the boilerplate needed to produce a robust, user-friendly Perl application. FYI PerlWizard is a Java application that uses the Freemarker template engine that reads a Perl template to generate Perl scripts. Best Regards, R. T. Bailey
Re: Propose for LINUX kernel and PERL
A useful Monks link here: http://www.perlmonks.org/?node=339754 and: http://www.foo.be/docs/tpj/issues/vol5_2/tpj0502-0009.html -- Ciao Richard Foley http://www.rfi.net/books.html On Sun, Jan 05, 2014 at 12:46:00AM -0500, Antti Heikkinen wrote: To Dear Perl and LINUX kernel development community: My propose to you at your list: is possible to write operate system in PERL? I am student in university, looked for interest project to conclude my study on LINUX kernel. This semester, I take beginner PERL course and learn power of procedural language. I automate many daily task with use of it. Very impressive ability to make many thing work, interpret or can compile also. Also about LINUX, I talk to much fellow students and professors, and take a operate system course use FreeBSD and LINUX. FreeBSD okay, but they say LINUX kernel is too big and bloat, run poor with too many developer. And too much quick decision from leader with ego is too big and bloat too, kekeke. LINUX kernel can perform more good if written in not C and C++ but Perl? Just certain portion of LINUX kernel to rewrite? For instant, schedule or support of multithread? If so, should use Perl5 or Perl6, focus to x86 or x86-64? Can you want to join me this my project? But to hear your expertise. Am excited to learn and begin study project. Can you want to join this my project? Please direct reply of email to myself. Much thank to you, Antti Heikkinen -- To unsubscribe, e-mail: beginners-unsubscr...@perl.org For additional commands, e-mail: beginners-h...@perl.org http://learn.perl.org/
Richard Fernandez
wer http://estetikburuncerrahisi.com/mr/lybibl/cddhmsewykrj/ubpejcbsumykym.php Richard Fernandez
perl hash loop: keys() vs values()
Hi
I'm trying to understand the difference between the keys() and values ()
operators. What I'm not getting is why a hash must be reversed to get the
key corresponding to a value? (as stated in perldoc). Can someone explain
this please?
Here is my test script; My perl is freebsd 5.8.9
use warnings;
use strict;
my %hds = ('1', '0C8CB35F', '2', '0C9CB37D');
print rows: . scalar keys(%hds) . \n\n;
my $value;
my $key;
foreach $value (values %hds) {
print key: $hds{$value} \n;
print value: $value \n;
}
print --- \n;
my %r_hds = reverse %hds;
foreach $value (values %hds) {
print key: $r_hds{$value} \n;
print value: $value \n;
}
print --- \n;
foreach $key (keys %hds) {
print key: $key \n;
print value: $hds{$key} \n;
}
Here is the output:
Use of uninitialized value in concatenation (.) or string at h line 11.
key:
value: 0C8CB35F
Use of uninitialized value in concatenation (.) or string at h line 11.
key:
value: 0C9CB37D
---
key: 1
value: 0C8CB35F
key: 2
value: 0C9CB37D
---
key: 1
value: 0C8CB35F
key: 2
value: 0C9CB37D
--
regards, Richard
--
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Re: perl hash loop: keys() vs values()
Octavian
Thanks for taking the time to write such a thorough reply. My question is
completely answered by this section:
You can't get the key for a certain value. Say you have the following hash:
my %hash = (a = 1, b = 2, c = 3, d = 2, e = 2);
What's the key for the value 2?
I was so preoccupied with values() and keys(), thinking of them as being
mirror-images of one another, that I forgot what a 'value' and a 'key'
were.
Thanks again
regards, Richard
--
tmqrich...@gmail.com
On Sat, Jun 15, 2013 at 2:19 PM, Octavian Rasnita orasn...@gmail.comwrote:
**
Perl has 2 types of arrays: common arrays and associative arrays which are
called hashes.
In order to get the value of an item from an ordinary array, you need to
specify the index of that array, for example:
my @array = (1, 2, 3);
print $array[1]; #will print 2 (because the indexes start from 0
A hash associates a key to any value and if you want to get the value, you
need to specify its key:
my %hash = (a = 1, b = 2, c = 3);
print $hash{b}; #will print 2
You can't get the key for a certain value. Say you have the following hash:
my %hash = (a = 1, b = 2, c = 3, d = 2, e = 2);
What's the key for the value 2?
The keys in a hash are always unique but the values can have duplicates.
If you reverse the hash, the keys become values and the values become
keys, so you will be able to use the value as a key. But if the values
have duplicates, your reversed hash will contain less elements because that
hash will contain unique keys.
In the example above, there would be just a single 2 key and not 3.
So, the question is why do you need to access the keys using their values?
Maybe you want to use an array of arrays like:
my @array = (
['a', 1],
['b', 2],
['c', '3],
['d', 2],
);
To get the value for the element with the index 1 you need to do:
my $value = $array[1][1]; #the value 2
and to get the key for the element with the index 1, you can do:
my $key = $array[1][0]; #Will get b
I don't know what you need to do... that's why I gave the idea of using
arrays of arrays...
--Octavian
- Original Message -
*From:* richard tmqrich...@gmail.com
*To:* beginners@perl.org
*Sent:* Saturday, June 15, 2013 7:12 PM
*Subject:* perl hash loop: keys() vs values()
Hi
I'm trying to understand the difference between the keys() and values ()
operators. What I'm not getting is why a hash must be reversed to get the
key corresponding to a value? (as stated in perldoc). Can someone explain
this please?
Here is my test script; My perl is freebsd 5.8.9
use warnings;
use strict;
my %hds = ('1', '0C8CB35F', '2', '0C9CB37D');
print rows: . scalar keys(%hds) . \n\n;
my $value;
my $key;
foreach $value (values %hds) {
print key: $hds{$value} \n;
print value: $value \n;
}
print --- \n;
my %r_hds = reverse %hds;
foreach $value (values %hds) {
print key: $r_hds{$value} \n;
print value: $value \n;
}
print --- \n;
foreach $key (keys %hds) {
print key: $key \n;
print value: $hds{$key} \n;
}
Here is the output:
Use of uninitialized value in concatenation (.) or string at h line 11.
key:
value: 0C8CB35F
Use of uninitialized value in concatenation (.) or string at h line 11.
key:
value: 0C9CB37D
---
key: 1
value: 0C8CB35F
key: 2
value: 0C9CB37D
---
key: 1
value: 0C8CB35F
key: 2
value: 0C9CB37D
--
regards, Richard
--
tmqrich...@gmail.com
Re: perl hash loop: keys() vs values()
Thanks. I looked at this site while searching for solutions but I probably skipped the section on sorting because I wasn't sorting the hash. regards, Richard -- tmqrich...@gmail.com On Sun, Jun 16, 2013 at 3:17 AM, Peter Gordon pete...@netspace.net.auwrote: On Sat, 15 Jun 2013 12:12:56 -0400, richard wrote: Hi I'm trying to understand the difference between the keys() and values () operators. What I'm not getting is why a hash must be reversed to get the key corresponding to a value? (as stated in perldoc). Can someone explain this please? Read http://www.tizag.com/perlT/perlhashes.php particularly the section on sort by keys by values. This should give you a good understanding of the how to use them. -- Peter Gordon, pete...@netspace.net.au on 06/16/2013 -- To unsubscribe, e-mail: beginners-unsubscr...@perl.org For additional commands, e-mail: beginners-h...@perl.org http://learn.perl.org/
string substitution command question
Hi Perl users, Quick question, I have a one long string with tab delimited values separated by a newline character (in rows) Here is a snippet of the the string: chr1ucscexon226488874 226488906 0.00 - . gene_id NM_173083; transcript_id NM_173083; chr1ucscexon226496810 226497198 0.00 - . gene_id NM_173083; transcript_id NM_173083; chr1ucscexon2005086 2005368 0.00+ . gene_id NM_001033581; transcript_id NM_001033581; chr1ucscexon2066701 2066786 0.00+ . gene_id NM_001033581; transcript_id NM_001033581; I am trying to perform substitution on some values at the end of each rows, for example, I'm trying to replace the above string with the following: chr1ucscexon226488874 226488906 0.00 - . gene_id NM_173083:12345; transcript_id NM_173083:12345; chr1ucscexon226496810 226497198 0.00 - . gene_id NM_173083:12345; transcript_id NM_173083:12345; chr1ucscexon2005086 2005368 0.00+ . gene_id NM_001033581:12346; transcript_id NM_001033581:12346; chr1ucscexon2066701 2066786 0.00+ . gene_id NM_001033581:12346; transcript_id NM_001033581:12346; Here is the substitution command I am trying to use: $data_string=~ s/$gene_id\NM_173083\\; transcript_id \NM_173083\\;/\NM_173083:12345\\; \NM_173083:12345\\;/g; $data_string=~ s/$gene_id\NM_001033581\\; transcript_id \NM_001033581\\;/\NM_001033581:12346\\; \NM_001033581:12346\\;/g; I don't know why I am not able to substitute at the end of each row in the string. Any suggestions folks have are muchly appreciated. Thanks -Rich
Re: string substitution command question
What is $gene_id? Are you by any chance using '$' at the beginning of your search pattern instead of the end? I have $ to designate the end of the row $gene_id Why are you escaping the quote marks? I thought it would be easier to perform substitution without them Why is there no space after 'gene_id'? I guess there should be On Feb 26, 2011, at 12:30 PM, John Delacour johndelac...@gmail.com wrote: At 12:06 -0800 26/02/2011, Richard Green wrote: chr1ucscexon226488874 226488906 0.00 - . gene_id NM_173083:12345; transcript_id NM_173083:12345; chr1ucscexon226496810 226497198 0.00 - . gene_id NM_173083:12345; transcript_id NM_173083:12345; chr1ucscexon2005086 2005368 0.00+ . gene_id NM_001033581:12346; transcript_id NM_001033581:12346; chr1ucscexon2066701 2066786 0.00+ . gene_id NM_001033581:12346; transcript_id NM_001033581:12346; Here is the substitution command I am trying to use: $data_string=~ s/$gene_id\NM_173083\\; transcript_id \NM_173083\\;/\NM_173083:12345\\; \NM_173083:12345\\;/g; $data_string=~ s/$gene_id\NM_001033581\\; transcript_id \NM_001033581\\;/\NM_001033581:12346\\; \NM_001033581:12346\\;/g; I don't know why I am not able to substitute at the end of each row in the string. What is $gene_id? Are you by any chance using '$' at the beginning of your search pattern instead of the end? Why are you escaping the quote marks? Why is there no space after 'gene_id'? JD -- To unsubscribe, e-mail: beginners-unsubscr...@perl.org For additional commands, e-mail: beginners-h...@perl.org http://learn.perl.org/ -- To unsubscribe, e-mail: beginners-unsubscr...@perl.org For additional commands, e-mail: beginners-h...@perl.org http://learn.perl.org/
Re: string substitution command question
Ok JD thanks On Feb 26, 2011, at 3:46 PM, John Delacour johndelac...@gmail.com wrote: At 12:57 -0800 26/02/2011, Richard Green wrote: What is $gene_id? Are you by any chance using '$' at the beginning of your search pattern instead of the end? I have $ to designate the end of the row $gene_id $gene_id designates $gene_id period. Why are you escaping the quote marks? I thought it would be easier to perform substitution without them What made you think that? Why is there no space after 'gene_id'? I guess there should be You can guess as much as you like but Perl Regular Expressions don't care what you think or what you guess. Read perlvar and pelretut. JD -- To unsubscribe, e-mail: beginners-unsubscr...@perl.org For additional commands, e-mail: beginners-h...@perl.org http://learn.perl.org/ -- To unsubscribe, e-mail: beginners-unsubscr...@perl.org For additional commands, e-mail: beginners-h...@perl.org http://learn.perl.org/
Re: Removing leading whitespace and removing alternate newlines
$string =~ s/^\s+//; http://oreilly.com/catalog/9781565922433/ page 43 That book is my bible!!! On Sun, Oct 31, 2010 at 11:01 AM, Brian brian5432...@yahoo.co.uk wrote: Hi guys, long time no working with PERL :-) I have just installed 5.2.12 First, I am trying to remove leading tabs spaces but the following leaves a few blanks at the beginning of each line, could someone be kind enough to point out the error of my ways please? :-) #!/usr/bin/perl local $/=undef; open(FILE, smith3.txt) || die (Error\n); $string = FILE; $string =~ s/\s//; #remove leading spaces print $string; Secondly, I would like to remove newline from alternate lines, ie I would like to remove from lines 1,3,5,7 etc. What would be the simplest way of getting even line numbers to print on the same line as odds? Thanks muchly Brian -- Richard Hug 813-973-3783 cell 813-361-7946
loading and comparing large hashes
Hi everyone, could use some advice on a perl script I wrote using hashes. I
have three files ( each file is a list of indexes) my program loads these
indexes into hashes and compares the differences and similarities between
them. With smaller files it runs fine. problem is I now files have about 88
million records and the script has been running for days. not sure the best
way to resolve the issue.(pieces of code samples below) One suggestion that
was given to me was to load the first file into a hash and then as I open
the next file I immediately do a comparison of the second hash into the 1st
one for similarities and differences. I can't really get my head around how
to that. Is there a simple way to compare three very large hashes without so
much demand on memory? The program manages to loads the large hashes without
problems and as I mentioned previously smaller files have no issues. Any
suggestions folks have are muchly appreciated.
Thanks R
#!/usr/bin/perl
use strict;
use warnings;
###loading file content into hashes
my $filename = '/tmp/test.txt';
open my $fh,,$filename or die $!;
my %hash = map { /(^ABC*.*?)\n(.*)/} $fh;
# get the hash size
my $hash_size = keys %trim5p;
print The hash contains $hash_size elements.\n;
close $fh or die $!;
##intersect subroutine
sub intersection
{
my ($hasha, $hashb) = @_;
my %newhash;
foreach my $key (keys %{$hasha})
{
$newhash{$key} = $$hasha{$key} if (exists $$hashb{$key});
}
# dont return %newhash just grab size
my $newhash_size = keys %newhash;
print The intersected hash contains $newhash_size elements.\n;
}
differences between hashes
sub in_one_not_in_both
{
#Find keys from one hash that aren't in both
my ($hash3, $hash4) = @_;
my %newhash2;
foreach my $key2 (keys %{$hash3})
{
$newhash2{$key2} = $$hash3{$key2} unless (exists $$hash4{$key2});
}
my $newhash_size2 = keys %newhash2;
print This is the number of unique values: $newhash_size2 \n;
}
How to remove duplicates from a hash
What would be the quickest , easiest way to remove duplicates from a hash? Any suggestions are muchly appreciated. Thanks -Rich -- To unsubscribe, e-mail: beginners-unsubscr...@perl.org For additional commands, e-mail: beginners-h...@perl.org http://learn.perl.org/
Re: How to remove duplicates from a hash
These are great suggestions thanks everyone! -Rich On Sep 29, 2010, at 2:39 AM, Paul Johnson p...@pjcj.net wrote: On Tue, Sep 28, 2010 at 08:10:30AM -0700, Richard Green wrote: What would be the quickest , easiest way to remove duplicates from a hash? Any suggestions are muchly appreciated. Thanks I presume you mean duplicate values, because hashes don't have duplicate keys. Do you care which values get removed? If not, then: %x = reverse %x; %x = reverse %x; will do the trick. That's the quickest and easiest method according to some criteria, anyway. -- Paul Johnson - p...@pjcj.net http://www.pjcj.net -- To unsubscribe, e-mail: beginners-unsubscr...@perl.org For additional commands, e-mail: beginners-h...@perl.org http://learn.perl.org/ -- To unsubscribe, e-mail: beginners-unsubscr...@perl.org For additional commands, e-mail: beginners-h...@perl.org http://learn.perl.org/
Re: How to Extract to a flat file thru Excel an Access DB file
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Wagner, David --- Senior Programmer Analyst --- CFS wrote: I have an Excel file that I am copying from a Windows server to Linux box(initially). I then extract each worksheet to their own csv. Within the Excel is detail that is contained within a Access DB. I am getting the necessary worksheets out ok, but am unsure how or if one can extract to a csv, the detail data from Access DB. Any thoughts or how one would research to do this? I am on 5.8.8 ActiveState Build 824. If you have any questions and/or problems, please let me know. Thanks. Wags ;) David R. Wagner Senior Programmer Analyst FedEx Freight 1.719.484.2097 TEL 1.719.484.2419 FAX 1.408.623.5963 Cell http://fedex.com/us Not Perl, but MDB Tools might be of use. From the FAQ: 1.2 What does MDB Tools do MDB Tools is an open source suite of libraries and utilities to read (and soon write) MDB database files. http://mdbtools.sourceforge.net/faq.html They say it'll run on Linux. Regards, Rich Loveland -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.6 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQFKCXQS4EG8v4hpG/ERAhJKAKCiUcv7YQ8ba5r81FadB37cEi0u4wCeKd7R tTsNRdT3wKlNasSI6FNvRsE= =JeS/ -END PGP SIGNATURE- -- To unsubscribe, e-mail: beginners-unsubscr...@perl.org For additional commands, e-mail: beginners-h...@perl.org http://learn.perl.org/
Re: Perl code for comparing two files
-BEGIN PGP SIGNED MESSAGE-
Hash: SHA1
Mr. Adhikary,
The following will take any number of files as arguments, in the format
you described (I even tested it! :-)). It goes through each line of
those files, stuffing (the relevant part of) each line in a 'seen' hash
(more on that, and other, hash techniques here if you're interested:
http://www.perl.com/pub/a/2006/11/02/all-about-hashes.html).
The code below does not keep track of line numbers as you requested, but
I think the hash technique used here could help you as you approach a
solution to your particular problem.
#!/usr/bin/perl
use strict;
use warnings;
use File::Slurp; # This is where 'read_file' lives
my %seen;
for my $arg ( @ARGV ) {
my @lines = read_file( $arg );
for my $line ( @lines ) {
chomp $line;
my @elems = split / /, $line;
my $value = $elems[1];
$seen{$value}++;
}
}
for my $k ( keys %seen ) {
print $k, \n if $seen{$k} 1;
}
Regards,
Rich Loveland
Anirban Adhikary wrote:
Hi List
I am writing a perl code which will takes 2 more files as argument. Then It
will check the the values of each line of a file with respect with another
file. If some value matches then it will write the value along with line
number to another ( say outputfile) file.
The source files are as follow
Contents of abc.txt
1 2325278241,P0
2 2296250723,MH
3 2296250724,MH
4 2325277178,P0
5 7067023316,WL
6 7067023329,WL
7 2296250759,MH
8 7067023453,WL
9 7067023455,WL
10 555413,EA05
###
Contents of xyz.txt
1 7067023453,WL
2 31-DEC-27,2O,7038590671
3 31-DEC-27,2O,7038596464
4 31-DEC-27,2O,7038596482
5 2296250724,MH
6 31-DEC-27,2O,7038597632
7 31-DEC-27,2O,7038589511
8 31-DEC-11,2O,7038590671
9 7067023455,WL
10 31-DEC-27,2O,7038555744
###
Contents of pqr.txt
1 2325278241,P0
2 7067023316,WL
3 7067023455,WL
4 2296250724,MH
For this requirement I have written the following code which works fine for
2 input files
use strict;
use warnings;
use Benchmark;
if(@ARGV 2) {
print Please enter atleast two or more .orig file names \n;
exit 0;
}
my @file_names = @ARGV;
chomp(@file_names);
my @files_to_process;
for(@file_names) {
if( -s $_){
print File $_ exists\n;
push(@files_to_process,$_);
}
elsif( -e $_) {
print File $_ exists but it has zero byte size\n;
}
else {
print File $_ does not exists \n;
}
}
my $count = @files_to_process;
if( $count 2 ) {
print Atleast 2 .orig files are required to continue this
program\n;
exit 0;
}
my $output_file = outputfile;
my $value = 0;
my $start_time = new Benchmark;
if( $count = 2 ) {
while ($count) {
my ($files_after_processing_pointer,$return_val) =
create_itermediate_file (\...@files_to_process,$value);
my @files_after_processing =
@$files_after_processing_pointer;
$count = @files_after_processing;
$value = $return_val;
@files_to_process = @files_after_processing;
}
my $end_time = new Benchmark;
my $difference = timediff($end_time, $start_time);
print It took , timestr($difference), to execute the program\n;
}
sub create_itermediate_file {
my $file_pointer = $_[0];
my $counter = $_[1];
my @file_content = @$file_pointer;
if($counter == 0) {
my($first_file,$second_file) = splice
(@file_content, 0, 2);
open my $orig_first, , $first_file
or die could not open $first_file: $!;
open my $orig_second, , $second_file
or die could not open $second_file:
$!;
open my $output_fh, , $output_file
or die could not open $output_file:
$!;
my %content_first;
while (my $line = $orig_first) {
chomp $line;
if ($line) {
my($line_num,$value) = split( ,$line);
$content_first{$value} = $line_num;
}
}
my %content_second;
while (my $line = $orig_second) {
chomp $line;
if ($line) {
my($line_num,$value) =
Having problems using HTML::HashTable and HTML::TableContentParser together.
Hi,
I'm trying to read an HTML table from JBoss's Destination Manager,
strip out only the table rows I'm interested in and then write it back
out as an HTML table. What I've done so far (see Fig 1 below) is to
grab every table off the page (although there is in fact only one)
into $tables. What I'm not sure of is how to turn that into a hash
that I can then write out with HTML::HashTable.
I printed the contents of $tables via Data::Dumper and got the
structure you see in Fig 2. Out of curiosity, I pasted that into my
code and assigned it to %table, but then the output of print
tablify... was:
table border=0
tr
tdHASH(0x199ca080)/td
td/td
/tr
/table
Presumably because it couldn't read down into the data structure I
gave it.
I'm at a bit of a loss as to how to convert one structure into the
other as I'm finding the dereferencing syntax for anonymous data
structures somewhat impenetrable. Can anyone help?
Regards,
Richard Cross.
-- Fig 1 - My code so far (I've cut out a whole load of extra CGI
stuff that isn't relevant to my question) --
#!/usr/bin/perl -w
use strict;
use CGI qw(:standard escapeHTML);
use HTML::HashTable;
use HTML::TableContentParser;
my $HTML = `./twiddle.sh invoke jboss.mq:service=DestinationManager
listMessageCounter`;
my $parser = HTML::TableContentParser-new;
my $tables = $parser-parse($HTML);
#
# I need to get the first element of $tables and somehow turn it into
a hash (%table) that I can use below
#
print tablify({
BORDER = 0,
DATA= \%table,
SORTBY = 'key',
ORDER = 'desc'}
);
-- Fig 2 - what is returned from HTML::TableContentParser --$VAR1 = [
{
'width' = '100%',
'cellspacing' = '1',
'cellpadding' = '1',
'border' = '1',
'headers' = [ { 'data' = 'Type' },
{ 'data' = 'Name' },
{ 'data' = 'Subscription' },
{ 'data' = 'Durable' },
{ 'data' = 'Count' },
{ 'data' = 'CountDelta' },
{ 'data' = 'Depth' },
{ 'data' = 'DepthDelta' },
{ 'data' = 'Last Add' }
],
'rows' = [ {},
{ 'cells' = [ { 'rowspan' = '1', 'data' =
'Queue' },
{ 'rowspan' = '1', 'data' =
'A' },
{ 'data' = '-' },
{ 'data' = '-' },
{ 'data' = '0' },
{ 'data' = '-' },
{ 'data' = '0' },
{ 'data' = '-' },
{ 'data' = '-' }
],
'bgcolor' = '#F0F0F0'
},
{ 'cells' = [ { 'rowspan' = '1', 'data' =
'Queue' },
{ 'rowspan' = '1', 'data' =
'B' },
{ 'data' = '-' },
{ 'data' = '-' },
{ 'data' = '0' },
{ 'data' = '-' },
{ 'data' = '0' },
{ 'data' = '-' },
{ 'data' = '-' }
],
'bgcolor' = '#FF'
},
],
}
];
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Programming Perl vs perldoc
So, I've done the Learning Perl book, and frustrating myself no end by trying to write a chess program using just the knowledge contained in Learning Perl and with no modules. I thought about getting Intermediate Perl, but I've heard that Programming Perl is the best next step. But, what's the advantage of Programming Perl when we have perldoc? What does the book give me that perldoc does not? Thanks, Richard -- To unsubscribe, e-mail: beginners-unsubscr...@perl.org For additional commands, e-mail: beginners-h...@perl.org http://learn.perl.org/
Re: Programming Perl vs perldoc
Thanks Brian On Wed, 08 Apr 2009 08:37 -0400, Brian J. Miller Interesting first choice, but okay... Was there something in particular that you are getting hung up on? Yeah, the complexity of chess! I'm getting there. I do miss a lot of short-cuts and efficiencies in Perl that would help, but this is a good exercise to learn Perl. I'd disagree and say that your suggestion of Intermediate Perl would be the next best step. A book. Some descriptions are more in depth and having a book with a table of contents and index can often be easier to reference when you don't know *where* to look in perldoc, but much of the information will be the same. (Any number of sites and Google can help with where to look.) OK. I'll probably stick with perldoc and get Intermediate Perl. I'm currently unemployed, so I can't really fork out for both books right now - but I have plenty of time to learn Perl! Cheers, Richard -- To unsubscribe, e-mail: beginners-unsubscr...@perl.org For additional commands, e-mail: beginners-h...@perl.org http://learn.perl.org/
Re: Programming Perl vs perldoc
Thanks Brian On Wed, 08 Apr 2009 08:37 -0400, Brian J. Miller Interesting first choice, but okay... Was there something in particular that you are getting hung up on? Yeah, the complexity of chess! I'm getting there. I do miss a lot of short-cuts and efficiencies in Perl that would help, but this is a good exercise to learn Perl. I'd disagree and say that your suggestion of Intermediate Perl would be the next best step. A book. Some descriptions are more in depth and having a book with a table of contents and index can often be easier to reference when you don't know *where* to look in perldoc, but much of the information will be the same. (Any number of sites and Google can help with where to look.) OK. I'll probably stick with perldoc and get Intermediate Perl. I'm currently unemployed, so I can't really fork out for both books right now - but I have plenty of time to learn Perl! Cheers, Richard -- To unsubscribe, e-mail: beginners-unsubscr...@perl.org For additional commands, e-mail: beginners-h...@perl.org http://learn.perl.org/
Re: Programming Perl vs perldoc
On Wed, 08 Apr 2009 08:50 -0400, Chas. Owens chas.ow...@gmail.com wrote: Your whois information suggests that you live in the US; I am always amazed to hear fellow Americans say things like that book is expensive. We have a wonderful lending library system in this country, use it. If your local library does not have the 3rd Edition of Programming Perl, then ask you librarian to order a copy. They generally want to help you. Actually, no. I live in the UK, and price for O'Reilly books here are significantly higher. Amazon US has Intermediate Perl new for $25, while Amazon UK has it for $46, excluding postage. Also, I live in a relatively small town in Scotland, whose libraries tend not to purchase obscure programming books on demand. Look, I'm not after pity. I just want advice about which book to get. Cheers, Richard -- To unsubscribe, e-mail: beginners-unsubscr...@perl.org For additional commands, e-mail: beginners-h...@perl.org http://learn.perl.org/
Pattern matching question
Hi,
Please be patient with this beginner. I have a subrouting as follows,
that prints out an ASCII representation of chess board
sub display_board {
foreach (0..7) {
my $ref = @_[$_];
foreach (0..7) {
my $piece = $ref-[$_];
$piece =~ /.*(..$)/;
print $pieces{$1};
}
print \n;
}
};
It works, but is there a way of combining these lines:
my $piece = $ref-[$_];
$piece =~ /.*(..$)/;
It feels like this could be done in one step. Is this correct? I'm
finding that I'm doing alright in Perl, but I sense the Perl urge to do
things in as few a number of steps as possible.
Thanks,
Richard Hobson
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Re: AW: Pattern matching question
Firstly, apologies for the double posting of this question.
On Wed, 01 Apr 2009 09:49 +0200, Thomas Bätzler
t.baetz...@bringe.com wrote:
How about (untested):
sub display_board {
foreach my $ref (@_){
foreach my $piece ( @$ref ){
print substr( $piece, -2);
}
}
}
The Perl way is to avoid using indices where you don't need them.
Yes, that works fine, and is far more elegant.
Thanks,
Richard
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Pattern matching question
Hi,
Please be patient with this beginner. I have a subrouting as follows,
that prints out an ASCII representation of chess board
sub display_board {
foreach (0..7) {
my $ref = @_[$_];
foreach (0..7) {
my $piece = $ref-[$_];
$piece =~ /.*(..$)/;
print $pieces{$1};
}
print \n;
}
};
It works, but is there a way of combining these lines:
my $piece = $ref-[$_];
$piece =~ /.*(..$)/;
It feels like this could be done in one step. Is this correct? I'm
finding that I'm doing alright in Perl, but I sense the Perl urge to do
things in as few a number of steps as possible.
Thanks,
Richard Hobson
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using (dot) . with printf does not incur the results I expected
what's wrong w/ this ?
I used (dot) . to indicate the maximum length of each element in the
print but last one does not print out in alinged format..
What am i missing?
use warnings;
use strict;
my $yabal = 'truncated';
my $never = 'sai';
my $noway = 'han1';
my %never = qw(hi how are you today fine i am good and everyday12345678
never12345689);
printf %-.5s %-15s %-.2s\n, $yabal, $never, $noway;
for (keys %never) {
printf %.2s %.10s\n, $_, $never{$_};
}
r...@myserver ~ ././yahoo2
trunc sai ha
hi how
go and
to fine
ar you
ev never12345
i am
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Re: using (dot) . with printf does not incur the results I expected
Richard wrote:
what's wrong w/ this ?
I used (dot) . to indicate the maximum length of each element in the
print but last one does not print out in alinged format..
What am i missing?
use warnings;
use strict;
my $yabal = 'truncated';
my $never = 'sai';
my $noway = 'han1';
my %never = qw(hi how are you today fine i am good and
everyday12345678 never12345689);
printf %-.5s %-15s %-.2s\n, $yabal, $never, $noway;
for (keys %never) {
printf %.2s %.10s\n, $_, $never{$_};
}
r...@myserver ~ ././yahoo2
trunc sai ha
hi how
go and
to fine
ar you
ev never12345
i am
I guess I was missing the 2.2 option...
my %never = qw(hi how are you today fine i am good and everyday12345678
never12345689);
for (keys %never) {
printf %-2.2s %-10.10s\n, $_, $never{$_};
}
r...@myserver ~ ./!$
././yahoo2
trunc sai ha
hi how
go and
to fine
ar you
ev never12345
i am
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Re: counter program by using closure
John W. Krahn wrote:
Richard wrote:
John W. Krahn wrote:
You want something more like this:
sub counter {
my $count;
my $clear = `clear`;
my $counting = 'EOF';
%s
| Counting...|
| %2d |
| |
EOF
return sub { local $| = 1; printf $counting, $clear, ++$count }
}
my $yeah = counter();
for ( 1 .. 35 ) {
sleep 1;
$yeah-();
}
this is interesting and this also works well.
My question is, how does perl know in this instance that %2d is
refering to $count.. is it because $clear contains none numeric value
or because $count contains numeric value?
$counting contains the format string for printf() and the first
argument $clear is substituted for '%s' in $counting and the second
argument ++$count is substituted for '%2d' in $counting. They are
substituted in the same order as they appear.
John
Just curious, in programming in general, is it possible to do other
things while counting is going on?
Is this possible in perl?
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Re: counter program by using closure
David Schmidt wrote: You might want to look into fork http://perldoc.perl.org/functions/fork.html http://www.tutorialspoint.com/perl/perl_fork.htm thank you.. I was experimenting w/ forks but I definitely need to understand forking better. thanks!! -- To unsubscribe, e-mail: beginners-unsubscr...@perl.org For additional commands, e-mail: beginners-h...@perl.org http://learn.perl.org/
Re: counter program by using closure
John W. Krahn wrote:
Richard wrote:
wanted to draw a box that's counting up for certain time.
Thought I could use the counter but it just displays the box not the
number..
can anyone point it out for me?
thank you.
use warnings;
use strict;
sub counter {
my $count;
my $counting = EOF;
|
Counting...
|
|
++$count;
|
|
|
EOF
return sub { print $counting }
}
my $real_count;
my $yeah = counter();
while ($real_count '35') {
++$real_count;
system('clear');
$yeah-();
}
You want something more like this:
sub counter {
my $count;
my $clear = `clear`;
my $counting = 'EOF';
%s
| Counting...|
| %2d |
| |
EOF
return sub { local $| = 1; printf $counting, $clear, ++$count }
}
my $yeah = counter();
for ( 1 .. 35 ) {
sleep 1;
$yeah-();
}
John
this is interesting and this also works well.
My question is, how does perl know in this instance that %2d is refering
to $count.. is it because $clear contains none numeric value or because
$count contains numeric value?
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Re: counter program by using closure
John W. Krahn wrote:
Richard wrote:
John W. Krahn wrote:
You want something more like this:
sub counter {
my $count;
my $clear = `clear`;
my $counting = 'EOF';
%s
| Counting...|
| %2d |
| |
EOF
return sub { local $| = 1; printf $counting, $clear, ++$count }
}
my $yeah = counter();
for ( 1 .. 35 ) {
sleep 1;
$yeah-();
}
this is interesting and this also works well.
My question is, how does perl know in this instance that %2d is
refering to $count.. is it because $clear contains none numeric value
or because $count contains numeric value?
$counting contains the format string for printf() and the first
argument $clear is substituted for '%s' in $counting and the second
argument ++$count is substituted for '%2d' in $counting. They are
substituted in the same order as they appear.
John
ah.. did not see the %s... and now that makes perfect sense.. thank you
very much!!!
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counter program by using closure
wanted to draw a box that's counting up for certain time.
Thought I could use the counter but it just displays the box not the
number..
can anyone point it out for me?
thank you.
use warnings;
use strict;
sub counter {
my $count;
my $counting = EOF;
| Counting...
|
| ++$count;
|
|
|
EOF
return sub { print $counting }
}
my $real_count;
my $yeah = counter();
while ($real_count '35') {
++$real_count;
system('clear');
$yeah-();
}
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Re: counter program by using closure
Richard wrote:
wanted to draw a box that's counting up for certain time.
Thought I could use the counter but it just displays the box not the
number..
can anyone point it out for me?
thank you.
use warnings;
use strict;
sub counter {
my $count;
my $counting = EOF;
|
Counting...
|
|
++$count;
|
|
|
EOF
return sub { print $counting }
}
my $real_count;
my $yeah = counter();
while ($real_count '35') {
++$real_count;
system('clear');
$yeah-();
}
I am assuming this will not work because above clousure will have no
access to variable $count.. trying to see if there is another way to get
this done.
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Re: counter program by using closure
Chas. Owens wrote:
On Sat, Dec 13, 2008 at 21:13, Richard rich.j...@gmail.com wrote:
wanted to draw a box that's counting up for certain time.
Thought I could use the counter but it just displays the box not the
number..
can anyone point it out for me?
thank you.
use warnings;
use strict;
sub counter {
my $count;
my $counting = EOF;
| Counting...
|
| ++$count;
|
|
|
EOF
return sub { print $counting }
}
my $real_count;
my $yeah = counter();
while ($real_count '35') {
++$real_count;
system('clear');
$yeah-();
}
The problem is that
my $counting = EOF;
| Counting...
|
| ++$count;
|
|
|
EOF
only gets executed once. Move it into your closure to execute it each
time the closure is called:O
#!/usr/bin/perl
use warnings;
use strict;
sub counter {
my $count;
return sub {
my $l = (length ++$count)/2 - .5;
my $r = (length $count)/2;
print
= x 52, \n,
|, x 20, Counting..., x 19, |\n,
|, x (25 - $l), $count, x (25 - $r), |\n,
|, x 50, |\n,
= x 52, \n;
}
}
my $yeah = counter();
for (1 .. 35) {
system('clear');
$yeah-();
select undef, undef, undef, .25;
}
WOW..
thank you and I will study this code now... this is great!!
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Re: not understanding pipe command
Raymond Wan wrote:
Hi Richard,
I'm no Perl expert, but it sounds like you are right.
Richard wrote:
still confused by after running this program.
1)when I do #print while READER; program only outputs
-- truly done
Let's comment out fibonacci, first. Then, my understanding of your
posted code is that the child process calculates the factorial and
sends it to the parent process. So, if you comment out print while
READER, then the parent process doesn't read what it received, and
just prints the single line.
2)here is my attempt for understanding of this program.
The parent process keeps one filehandle and closes the other,
while the child does the opposite. The parent
and child process can now communicate acorss the pipe as they
work in parallel
because above statement from the book network programming with
perl... my thought is
a)child choose to write to filehandle WRITER and have all the
output from factorial and fibonacci go there
b)parent choose to close WRITER and read from READER because that's
what it will be able to read since READER will have
all the output from child's filehandle WRITER
am I interpreting this right way? or close?
Yes, that sounds right. Again, ignoring fibonacci, the child does
the calculations and sends what it has to the parent and exits. The
parent reads it in, prints it out using the line mentioned above, and
finishes it with a truly done message.
That line print while READER is doing two important functions in
the parent...reading from the input pipe, and then immediately writing
it out.
So, yes, I don't see anything wrong with what you said. Oh, just one
thing -- with the two forks, there are actually two children if you
bring fibonacci in. This phrase helped me -- it is from the
definition of pipe in the Programming Perl book (i.e., the camel book):
This call [pipe] is almost always used right before a fork, after
which the pipe's reader should close WRITEHANDLE, and the writer close
READHANDLE. (Otherwise the pipe won't indicate EOF to the reader when
the writer closes it.) Note that if you set up a loop of piped
processes, deadlock can occur unless you are very careful. In
addition, note that Perl's pipes use standard I/O buffering, so you
may need to set $| on your WRITEHANDLE to flush after each output
command, ...
Hope this helps...
Ray
my $arg = shift || '10';
pipe(READER,WRITER) or die Can't open pipe: $!\n;
### pipe(READHANDLE, WRITEHANDLE) --- first is the name of a
filehandle to read from
### 2nd is filehandle to write
to. IF successful, pipe() returns a true result code
if ( fork == '0' ) {
close READER;
select WRITER; $| = '1';
factorial($arg);
print done with factorial\n;
exit 0;
}
if ( fork == '0' ) {
close READER;
select WRITER; $| = '1';
my $result = fibonacci($arg);
print done with fibonacci here\n;
exit 0;
}
#parent process closes WRITER and reads from READER
close WRITER;
print while READER;
print truly done\n;
sub factorial {
my $target = shift;
for ( my $result = 1, my $i = 1; $i = $target; $i++ ) {
print hi\n;
print factorial($i) = , $result *= $i, \n;
}
}
sub fibonacci {
my $target = shift;
my ($a,$b) = (1,0);
for ( my $i = 1; $i = $target; $i++ ) {
my $c = $a + $b;
print hi2\n;
print fibonacci($i) = $c\n;
($a,$b) = ($b,$c);
}
}
thank you!!
I will explorer this bit further and post a code based on it..
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Re: not understanding pipe command
Raymond Wan wrote:
Hi Richard,
Richard wrote:
while going over below example from the book, I am not understanding
why/how below program works.
Can someone explain this to me in better way?
Have you tried running it? does it work like what you expect?
what is READER exactly reading from???
and what does print while READER do ? I thought all the print
happens during factorial() and fibonacci()
It is reading from a pipe. Take a look at the description of the pipe
function and what a pipe is (in case you do not know):
http://perldoc.perl.org/functions/pipe.html
http://en.wikipedia.org/wiki/Pipe_(Unix)
is reading in from the pipe. Take a look at:
http://perldoc.perl.org/perlop.html#I%2fO-Operators
So, while there is something left to read, print it out. Go to the
above link and look at the first shaded box which says The following
lines are equivalent. The line that is confusing you is the last
line in that box...as it says, all of those are equivalent.
to answer your last question, then, the answer is no, the printing
isn't happening in just the two functions you named. Take a look at
the above links to see if they give you a clue. And if you are
wondering what the select line is doing, take a look at this and look
up the select function:
http://perldoc.perl.org/perlfaq5.html#How-do-I-flush%2funbuffer-an-output-filehandle%3f--Why-must-I-do-this%3f
And BTW, you can cut out almost half of the code if you just focus on
either fibonacci or factorial and not both.
Ray
ok so here is my attempt to understand this,
serverX ~/.sc/net ./pipe.pl 2
hi2
fibonacci(1) = 1
hi2
fibonacci(2) = 1
done with fibonacci here
hi
factorial(1) = 1
hi
factorial(2) = 2
done with factorial
truly done
serverX ~/.sc/net ./pipe.pl 10
hi
factorial(1) = 1
hi
factorial(2) = 2
hi
factorial(3) = 6
hi
factorial(4) = 24
hi
factorial(5) = 120
hi
factorial(6) = 720
hi
factorial(7) = 5040
hi
factorial(8) = 40320
hi
factorial(9) = 362880
hi
factorial(10) = 3628800
done with factorial
hi2
fibonacci(1) = 1
hi2
fibonacci(2) = 1
hi2
fibonacci(3) = 2
hi2
fibonacci(4) = 3
hi2
fibonacci(5) = 5
hi2
fibonacci(6) = 8
hi2
fibonacci(7) = 13
hi2
fibonacci(8) = 21
hi2
fibonacci(9) = 34
hi2
fibonacci(10) = 55
done with fibonacci here
truly done
still confused by after running this program.
1)when I do #print while READER; program only outputs
-- truly done
2)here is my attempt for understanding of this program.
The parent process keeps one filehandle and closes the other, while
the child does the opposite. The parent
and child process can now communicate acorss the pipe as they work
in parallel
because above statement from the book network programming with
perl... my thought is
a)child choose to write to filehandle WRITER and have all the output
from factorial and fibonacci go there
b)parent choose to close WRITER and read from READER because that's
what it will be able to read since READER will have
all the output from child's filehandle WRITER
am I interpreting this right way? or close?
my $arg = shift || '10';
pipe(READER,WRITER) or die Can't open pipe: $!\n;
### pipe(READHANDLE, WRITEHANDLE) --- first is the name of a
filehandle to read from
### 2nd is filehandle to write to.
IF successful, pipe() returns a true result code
if ( fork == '0' ) {
close READER;
select WRITER; $| = '1';
factorial($arg);
print done with factorial\n;
exit 0;
}
if ( fork == '0' ) {
close READER;
select WRITER; $| = '1';
my $result = fibonacci($arg);
print done with fibonacci here\n;
exit 0;
}
#parent process closes WRITER and reads from READER
close WRITER;
print while READER;
print truly done\n;
sub factorial {
my $target = shift;
for ( my $result = 1, my $i = 1; $i = $target; $i++ ) {
print hi\n;
print factorial($i) = , $result *= $i, \n;
}
}
sub fibonacci {
my $target = shift;
my ($a,$b) = (1,0);
for ( my $i = 1; $i = $target; $i++ ) {
my $c = $a + $b;
print hi2\n;
print fibonacci($i) = $c\n;
($a,$b) = ($b,$c);
}
}
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Re: not understanding pipe command
Raymond Wan wrote: Hi Richard, Richard wrote: while going over below example from the book, I am not understanding why/how below program works. Can someone explain this to me in better way? Have you tried running it? does it work like what you expect? what is READER exactly reading from??? and what does print while READER do ? I thought all the print happens during factorial() and fibonacci() It is reading from a pipe. Take a look at the description of the pipe function and what a pipe is (in case you do not know): http://perldoc.perl.org/functions/pipe.html http://en.wikipedia.org/wiki/Pipe_(Unix) is reading in from the pipe. Take a look at: http://perldoc.perl.org/perlop.html#I%2fO-Operators So, while there is something left to read, print it out. Go to the above link and look at the first shaded box which says The following lines are equivalent. The line that is confusing you is the last line in that box...as it says, all of those are equivalent. to answer your last question, then, the answer is no, the printing isn't happening in just the two functions you named. Take a look at the above links to see if they give you a clue. And if you are wondering what the select line is doing, take a look at this and look up the select function: http://perldoc.perl.org/perlfaq5.html#How-do-I-flush%2funbuffer-an-output-filehandle%3f--Why-must-I-do-this%3f And BTW, you can cut out almost half of the code if you just focus on either fibonacci or factorial and not both. Ray thanks!! I will study them and let you know. -- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] http://learn.perl.org/
not understanding pipe command
while going over below example from the book, I am not understanding
why/how below program works.
Can someone explain this to me in better way?
what is READER exactly reading from???
and what does print while READER do ? I thought all the print happens
during factorial() and fibonacci()
use warnings;
use strict;
my $arg = shift || '10';
pipe(READER,WRITER) or die Can't open pipe: $!\n;
### pipe(READHANDLE, WRITEHANDLE) --- first is the name of a
filehandle to read from
### 2nd is filehandle to write to.
IF successful, pipe() returns a true result code
if ( fork == '0' ) {
close READER;
select WRITER; $| = '1';
factorial($arg);
exit 0;
}
if ( fork == '0' ) {
close READER;
select WRITER; $| = '1';
my $result = fibonacci($arg);
exit 0;
}
#parent process closes WRITER and reads from READER
close WRITER;
print while READER;
sub factorial {
my $target = shift;
for ( my $result = 1, my $i = 1; $i = $target; $i++ ) {
print factorial($i) = , $result *= $i, \n;
}
}
sub fibonacci {
my $target = shift;
my ($a,$b) = (1,0);
for ( my $i = 1; $i = $target; $i++ ) {
my $c = $a + $b;
print fibonacci($i) = $c\n;
($a,$b) = ($b,$c);
}
}
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capturing output from c program inside of perl
i have a c program that I want to just run from perl and capture output I would have thought my $c_output = `/tmp/c_program`; would get me the output of the program. instead it prints out to the screen. Is there way to redirect STOUT just for that line and put it back to normal? -- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] http://learn.perl.org/
Re: capturing output from c program inside of perl
Chas. Owens wrote: On Sun, Nov 30, 2008 at 00:52, Richard [EMAIL PROTECTED] wrote: i have a c program that I want to just run from perl and capture output I would have thought my $c_output = `/tmp/c_program`; would get me the output of the program. instead it prints out to the screen. Is there way to redirect STOUT just for that line and put it back to normal? Take a closer look at your c program. Backticks do indeed grab stdout, so it must be writing to stderr (or worse yet the console). Try my $c_output = `/tmp/c_program 21`; thank you guys!! 21 fixed the issue.. -- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] http://learn.perl.org/
Re: removing files in unix or linux using glob?
Mr. Shawn H. Corey wrote: See: * perldoc -f unlink * perldoc -f glob * perldoc perlfunc and search for -f under Alphabetical Listing of Perl Functions one more question on this.. suppose there is 3 files in temp directory /tmp/yahoo1 /tmp/yahoo2 /tmp/yahoo3 and I wanted to take the last file that was created.. would this work? my $filename = shift; my @file_1 = /tmp/$filename*; my $file_1 = $file_1[-1]; push @files, $file_1; -- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] http://learn.perl.org/
Re: removing files in unix or linux using glob?
Richard Lee wrote:
stion on this.. suppose there is 3 files in temp directory
/tmp/yahoo1
/tmp/yahoo2
/tmp/yahoo3
and I wanted to take the last file that was created.. would this work?
my $filename = shift;
my @file_1 = /tmp/$filename*;
my $file_1 = $file_1[-1];
push @files, $file_1;
i am not 100% sure if this logic is correct or not.
my %big_hash;
for (@file_1) {
$big_hash{$_} = (stat($_))[9];
}
my @keys = sort { $big_hash{$a} = $big_hash{b} } keys %big_hash;
my $file_1 = $keys[-1];
push @files, $file_1;
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Re: removing files in unix or linux using glob?
Richard Lee wrote:
Richard Lee wrote:
stion on this.. suppose there is 3 files in temp directory
/tmp/yahoo1
/tmp/yahoo2
/tmp/yahoo3
and I wanted to take the last file that was created.. would this work?
my $filename = shift;
my @file_1 = /tmp/$filename*;
my $file_1 = $file_1[-1];
push @files, $file_1;
i am not 100% sure if this logic is correct or not.
my %big_hash;
for (@file_1) {
$big_hash{$_} = (stat($_))[9];
}
my @keys = sort { $big_hash{$a} = $big_hash{b} } keys %big_hash;
my $file_1 = $keys[-1];
push @files, $file_1;
I am missing a $ in $big_hash{b}.. and i see that this method works..
but is there easier and better(correct) way to do this ???
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removing files in unix or linux using glob?
I thought I could do this,
if ( -f q#/tmp/yahoo.* ) {
system(rm -rf /tmp/yahoo.*);
}
what am i missing?
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Re: removing files in unix or linux using glob?
Mr. Shawn H. Corey wrote:
for my $file ( glob( '/tmp/yahoo.*' ) ){
unlink $file if -f $file;
}
See:
* perldoc -f unlink
* perldoc -f glob
* perldoc perlfunc and search for -f under Alphabetical Listing
of Perl Functions
thanks, I tried
if ( -f q#/tmp/text.*# ) {
system(rm -rf /tmp/text.*);
}
and worked.. but above seems better.. i will read up on those as well..
thank you.
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what was the name of the new perl site which had link to all perl journal published.. in pdf format somebody posted that before here
please help.. -- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] http://learn.perl.org/
Re: what was the name of the new perl site which had link to all perl journal published.. in pdf format somebody posted that before here
Chas. Owens wrote: On Wed, Nov 19, 2008 at 22:48, Richard Lee [EMAIL PROTECTED] wrote: please help.. Is this what you are looking for? http://www.perlmonks.org/index.pl?node_id=711609 exactly!! thank you -- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] http://learn.perl.org/
can you substitute equation with variable?
say something like == or eq ..
Can you sub them w/ varilable like $unknown ?
Let me be more specific.
Let's say I don't know what the variable will hold
I guess I can say something like,
sub check_unknown {
my $unknown = shift; ## it's either digits or letters but both
will be same kind
my $unknown1 = shift; ## it's either digits or letters
my $result = ( $unknown =~ /^\d+$/ ) ? '==' : 'eq';
if ( $unknown $result $unknown1 ) {
do something...
}
}
But obviously above dont work.. can someone shed some light on this?
thanks!
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Re: can you substitute equation with variable?
Chas. Owens wrote:
On Mon, Nov 17, 2008 at 04:47, Richard Lee [EMAIL PROTECTED] wrote:
but it would only be worthwhile if you used $compare a lot after
setting it once; otherwise it would be simpler to just say
sub compare {
my ($x, $y) = @_;
return looks_like_number($x) ? $x == $y : $x eq $y;
}
Hi Chas,
This is nice and I will try it...
but I am suprised that perl doesn't have neutral equator..
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Re: xml question for xml::twig
Richard Lee wrote:
Richard Lee wrote:
Chas. Owens wrote:
my $sabal = new XML::Twig(
twig_roots = {
'foo/yahoo' =
#'[EMAIL PROTECTED]kingtony]' =
sub {
my ($yabal, $element ) = @_;
if (
$element-first_child('bayking_list')-first_child('bayking')-att('id')
eq 'kingtony' ) {
$element-print;
}
}
}
);
I think I made a mistake .. this is now working...
yahoo
V=bazbay_idvalue1000/valuefactyes/fact/bay_idbay_seenvalue50/valuefactno/fact/bay_seenbay_overall
value=disabled/bayking_listbayking active=true
country=Russia id=kingtonybayking type=dictator/bay_usage
value=none/bayking_originbayking_origin_name emmigrate=no
value=ohio_usaeconomy_status_previous value=very
poor//bayking_origin_name/bayking_origin/bayking/bayking_listbayqueen_listbayqueen
active=true country=japan id=queensarahbayqueen
type=dictator/bay_usage
value=none/bayqueen_originbayqueen_origin_name emmigrate=no
value=ca_usa/economy_status_previous value=very poor/previous
marriage=no//bayqueen_origin/bayqueen/bayqueen_list/yahoo
Now, I just need good way to put this into hash of hash referernce.
ok so I gave up putting them into has of hash reference because of
unpredictableness of items..
I can get to all values by doing manual $_-first_child method... but my
problem is, I don't know how to extract all information on
yahoo V=baz. how do I get that? $_-parent?
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Re: xml question for xml::twig
Richard Lee wrote: I think I made a mistake .. this is now working... yahoo V=bazbay_idvalue1000/valuefactyes/fact/bay_idbay_seenvalue50/valuefactno/fact/bay_seenbay_overall value=disabled/bayking_listbayking active=true country=Russia id=kingtonybayking type=dictator/bay_usage value=none/bayking_originbayking_origin_name emmigrate=no value=ohio_usaeconomy_status_previous value=very poor//bayking_origin_name/bayking_origin/bayking/bayking_listbayqueen_listbayqueen active=true country=japan id=queensarahbayqueen type=dictator/bay_usage value=none/bayqueen_originbayqueen_origin_name emmigrate=no value=ca_usa/economy_status_previous value=very poor/previous marriage=no//bayqueen_origin/bayqueen/bayqueen_list/yahoo Now, I just need good way to put this into hash of hash referernce. ok so I gave up putting them into has of hash reference because of unpredictableness of items.. I can get to all values by doing manual $_-first_child method... but my problem is, I don't know how to extract all information on yahoo V=baz. how do I get that? $_-parent? After I extracted above xml, what is the proper way to loop through them and extract all information? I like my final output to look like, yahoo V: baz bay_id value: 1000 fact: yes bay_seen value: 50 fact: no .. and so on -- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] http://learn.perl.org/
xml question for xml::twig
Hello, I am praticing below XML file.
Based on where I find att id for bayking id 'kingtony' , I wanted to
print out the entire element/att(and ID) and any text found from
yahoo to /yahoo.(exception of bayqueen_list and its descendatns)...
I am having problem just print out one value... can someone take a look
please?
use strict;
use warnings;
use XML::Twig;
my $xml = XML;
foo
yahoo V=bay
bay_id
value1/value
factyes/fact
/bay_id
bay_seen
value10/value
factno/fact
/bay_seen
bay_overall value=disabled/
bayking_list
bayking id=kingjames country=usa active=true
bayking type=dictator/
bay_usage value=none/
bayking_origin
bayking_origin_name value=ohio_usa
emmigrate=no
economy_status_previous value=very poor /
/bayking_origin_name
/bayking_origin
/bayking
/bayking_list
bayqueen_list
bayqueen id=queenliz country=france active=true
bayqueen type=dictator/
bay_usage value=none/
bayqueen_origin
bayqueen_origin_name value=ohio_usa
emmigrate=no/
/bayqueen_origin
/bayqueen
/bayqueen_list
/yahoo
yahoo V=baz
bay_id
value1000/value
factyes/fact
/bay_id
bay_seen
value50/value
factno/fact
/bay_seen
bay_overall value=disabled/
bayking_list
bayking id=kingtony country=Russia active=true
bayking type=dictator/
bay_usage value=none/
bayking_origin
bayking_origin_name value=ohio_usa
emmigrate=no
economy_status_previous value=very poor /
/bayking_origin_name
/bayking_origin
/bayking
/bayking_list
bayqueen_list
bayqueen id=queensarah country=japan active=true
bayqueen type=dictator/
bay_usage value=none/
bayqueen_origin
bayqueen_origin_name value=ca_usa
emmigrate=no/
economy_status_previous value=very poor /
previous marriage=no/
/bayqueen_origin
/bayqueen
/bayqueen_list
/yahoo
/foo
XML
my $t = XML::Twig-new
(
twig_handlers = { '/foo/yahoo/bayking_list' = sub
{
my @bay = $_-children('bayking');
foreach my $bay1 ( @bay ) {
if ( $bay1-att('id' eq 'kingtony' ) ) {
# print all elements/att/value and text from yahoo to
/yahoo which contains kingtony but do NOT print out bayqueen
print $bay1-att('id') . \n;
}
}
}
}
);
$t-parse ($xml);
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Re: xml question for xml::twig
use strict;
use warnings;
use XML::Twig;
my $xml = XML;
foo
yahoo V=bay
bay_id
value1/value
factyes/fact
/bay_id
bay_seen
value10/value
factno/fact
/bay_seen
bay_overall value=disabled/
bayking_list
bayking id=kingjames country=usa active=true
bayking type=dictator/
bay_usage value=none/
bayking_origin
bayking_origin_name value=ohio_usa
emmigrate=no
economy_status_previous value=very poor /
/bayking_origin_name
/bayking_origin
/bayking
/bayking_list
bayqueen_list
bayqueen id=queenliz country=france active=true
bayqueen type=dictator/
bay_usage value=none/
bayqueen_origin
bayqueen_origin_name value=ohio_usa
emmigrate=no/
/bayqueen_origin
/bayqueen
/bayqueen_list
/yahoo
yahoo V=baz
bay_id
value1000/value
factyes/fact
/bay_id
bay_seen
value50/value
factno/fact
/bay_seen
bay_overall value=disabled/
bayking_list
bayking id=kingtony country=Russia active=true
bayking type=dictator/
bay_usage value=none/
bayking_origin
bayking_origin_name value=ohio_usa
emmigrate=no
economy_status_previous value=very poor /
/bayking_origin_name
/bayking_origin
/bayking
/bayking_list
bayqueen_list
bayqueen id=queensarah country=japan active=true
bayqueen type=dictator/
bay_usage value=none/
bayqueen_origin
bayqueen_origin_name value=ca_usa
emmigrate=no/
economy_status_previous value=very poor /
previous marriage=no/
/bayqueen_origin
/bayqueen
/bayqueen_list
/yahoo
/foo
XML
my $sabal = new XML::Twig(
twig_roots = {
'[EMAIL PROTECTED]kingtony]' =
sub {
my ($yabal, $element ) = @_;
$element-print;
}
}
);
above produces,
bayking active=true country=Russia id=kingtonybayking
type=dictator/bay_usage
value=none/bayking_originbayking_origin_name emmigrate=no
value=ohio_usaeconomy_status_previous value=very
poor//bayking_origin_name/bayking_origin/bayking
which is very close to what i need but I really need it to traverse all
the way top to yahoo and traverse down back all the way to /yahoo..
I thought sub'ing $element-print to //../../$element-print would work
but does not
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Re: xml question for xml::twig
Chas. Owens wrote:
On Sat, Nov 15, 2008 at 16:27, Richard Lee [EMAIL PROTECTED] wrote:
snip
if ( $bay1-att('id' eq 'kingtony' ) ) {
snip
I think you mean to say
if ($bay1-att(id) eq kingtony) {
yes, that was a typo...
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Re: xml question for xml::twig
Richard Lee wrote:
Chas. Owens wrote:
On Sat, Nov 15, 2008 at 16:27, Richard Lee [EMAIL PROTECTED] wrote:
snip
if ( $bay1-att('id' eq 'kingtony' ) ) {
snip
I think you mean to say
if ($bay1-att(id) eq kingtony) {
yes, that was a typo...
I changed to
my $sabal = new XML::Twig(
twig_roots = {
'foo/yahoo' =
#'[EMAIL PROTECTED]kingtony]' =
sub {
my ($yabal, $element ) = @_;
if (
$yabal-first_child('bayking_list')-first_child('bayking')-att('id')
eq 'kingtony' ) {
$element-print;
}
}
}
);
$sabal-parse($xml);
but still no luck..
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Re: xml question for xml::twig
Chas. Owens wrote:
Perhaps I am dense, but what is the desired output from the given XML?
Hello Chas,
From xml file, based on attribute value for bayking id, I want to find
kingtony and then I want to traverse back up to yahoo and print
everything from
yahoo to /yahoo
I have tried to use xpath //../../bayking but doesn't seem to work.
I am trying to ultimately push below find value into hash of hash
reference such as
yahoo V=baz $list{'yahoo'} = { 'V' = 'baz'}
bayking id=kingtony country=Russia active=true
$list{'bayking'} = { 'id' = 'kingtony' , 'country' = 'Russia',
'active' = 'true' }
I am able to find what I am looking for 'kingtony' but having tough time
traversing back to right yahoo element and accessing all data.
yahoo V=baz
bay_id
value1000/value
factyes/fact
/bay_id
bay_seen
value50/value
factno/fact
/bay_seen
bay_overall value=disabled/
bayking_list
bayking id=kingtony country=Russia active=true
bayking type=dictator/
bay_usage value=none/
bayking_origin
bayking_origin_name value=ohio_usa
emmigrate=no
economy_status_previous value=very poor /
/bayking_origin_name
/bayking_origin
/bayking
/bayking_list
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Re: xml question for xml::twig
Richard Lee wrote:
Chas. Owens wrote:
my $sabal = new XML::Twig(
twig_roots = {
'foo/yahoo' =
#'[EMAIL PROTECTED]kingtony]' =
sub {
my ($yabal, $element ) = @_;
if (
$element-first_child('bayking_list')-first_child('bayking')-att('id')
eq 'kingtony' ) {
$element-print;
}
}
}
);
I think I made a mistake .. this is now working...
yahoo
V=bazbay_idvalue1000/valuefactyes/fact/bay_idbay_seenvalue50/valuefactno/fact/bay_seenbay_overall
value=disabled/bayking_listbayking active=true country=Russia
id=kingtonybayking type=dictator/bay_usage
value=none/bayking_originbayking_origin_name emmigrate=no
value=ohio_usaeconomy_status_previous value=very
poor//bayking_origin_name/bayking_origin/bayking/bayking_listbayqueen_listbayqueen
active=true country=japan id=queensarahbayqueen
type=dictator/bay_usage
value=none/bayqueen_originbayqueen_origin_name emmigrate=no
value=ca_usa/economy_status_previous value=very poor/previous
marriage=no//bayqueen_origin/bayqueen/bayqueen_list/yahoo
Now, I just need good way to put this into hash of hash referernce.
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please explain the anonymous sub usage in one of the article from stonehenge in detail for me
http://www.stonehenge.com/merlyn/UnixReview/col08.html
From above article, I am not fully understanding what's going on on
below code.
1)is there any difference in $next = $non_blank(STDIN) and
$next=$non_blank( sub{ STDIN }) in terms of funcaitonality?
I am not fully understanding the difference in anonymous sub vs just
having regular STDIN in there
2)in non_blank sub, my *guess is { $scanner }() is trying to
dereference the anonymous sub routine... is () necessary there?
Please kindly explain as it's bit over my head at this point but I do
enjoy the article immensenly..
thank you in advance.
$next = non_blank(
sub { STDIN; }
); # read from stdin
$next = non_blank(
sub { shift @cache; }
}; # grab from list @cache
sub non_blank {
my($scanner) = @_;
my($return);
{
$return = {$scanner}();
last unless defined $return;
redo until $return =~ /\S/;
}
$return;
}
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Re: please explain the anonymous sub usage in one of the article from stonehenge in detail for me
Jenda Krynicky wrote:
If we name the subroutine the code would look like this:
sub read_from_stdin {
return STDIN;
}
...
$next = non_blank(\read_from_stdin);
that is again the non_blank() would receive a reference to a
subroutine that reads one line from STDIN whenever called.
(actually this is not entirely true, the behaviour of the subroutine
in both cases depends on the context. In scalar context it reads just
one line, in list context it reads all remaining lines.)
Excellent!!! this is very clear... (I mean I am sure article was very
clear to regular readers.. i am just bit slow but this is great!!)
I am not fully understanding the difference in anonymous sub vs just
having regular STDIN in there
2)in non_blank sub, my *guess is { $scanner }() is trying to
dereference the anonymous sub routine... is () necessary there?
We need to dereference and thus call the subroutine, but you are
right that the () is not necessary there. I like this syntax better
though:
$scanner-()
but it means the same.
thank you for the confirmation!!
Jenda
= [EMAIL PROTECTED] === http://Jenda.Krynicky.cz =
When it comes to wine, women and song, wizards are allowed
to get drunk and croon as much as they like.
-- Terry Pratchett in Sourcery
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trying to parse out the simple xml file from the book with XML::Parser and I get not well-formed error
Not sure why I get this..
As xml file is very very simple one(I even tried to put different
encoding as well).
Below is all necessary information.
[EMAIL PROTECTED] script]# uname -a
Linux xmen 2.6.25.14-108.fc9.i686 #1 SMP Mon Aug 4 14:08:11 EDT 2008
i686 i686 i386 GNU/Linux
[EMAIL PROTECTED] script]# cat /etc/issue
Fedora release 9 (Sulphur)
Kernel \r on an \m (\l)
fortune | cowsay
[EMAIL PROTECTED] script]# ./weather.pl weather.xml
not well-formed (invalid token) at line 3, column 26, byte 60 at
/usr/lib/perl5/vendor_perl/5.10.0/i386-linux-thread-multi/XML/Parser.pm
line 187
?xml version='1.0' ?
FORECAST
OUTLOOKPartly Cloudy\OUTLOOK
TEMPERATURE TYPE=MAX DEGREES=C12/TEMPERATURE
!-- TEMPERATURE TYPE=MIN DEGREES=C6/TEMPERAURE --
/FORECAST
use strict;
use warnings;
use XML::Parser;
my %forecast;
my @curr;
my $type;
my $p1 = new XML::Parser(Style = 'Stream');
my $yahoo = shift;
$p1-parsefile($yahoo);
print Outlook: $forecast{outlook}\n;
foreach (keys %forecast) {
next if /outlook/;
print $_: $forecast{$_}-{val} $forecast{$_}-{deg}\n;
}
sub StartTag {
my ($p, $tag) = @_;
push @curr, $tag;
if ($tag eq 'TEMPERATURE') {
$type = $_{TYPE};
$forecast{$type}-{deg} = $_{DEGREES};
}
}
sub EndTag {
pop @curr;
}
sub Text {
my ($p) = shift;
return unless /\S/;
s/^\s+//;
s/^\s+$//;
if ($curr[-1] eq 'OUTLOOK') {
$forecast{outlook} .= $_;
} elsif ( $curr[-1] eq 'TEMPERATURE' ) {
$forecast{$type}-{val} = $_;
}
}
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Re: trying to parse out the simple xml file from the book with XML::Parser and I get not well-formed error
Richard Lee wrote:
Not sure why I get this..
As xml file is very very simple one(I even tried to put different
encoding as well).
Below is all necessary information.
[EMAIL PROTECTED] script]# uname -a
Linux xmen 2.6.25.14-108.fc9.i686 #1 SMP Mon Aug 4 14:08:11 EDT 2008
i686 i686 i386 GNU/Linux
[EMAIL PROTECTED] script]# cat /etc/issue
Fedora release 9 (Sulphur)
Kernel \r on an \m (\l)
fortune | cowsay
[EMAIL PROTECTED] script]# ./weather.pl weather.xml
not well-formed (invalid token) at line 3, column 26, byte 60 at
/usr/lib/perl5/vendor_perl/5.10.0/i386-linux-thread-multi/XML/Parser.pm
line 187
?xml version='1.0' ?
FORECAST
OUTLOOKPartly Cloudy\OUTLOOK
TEMPERATURE TYPE=MAX DEGREES=C12/TEMPERATURE
!-- TEMPERATURE TYPE=MIN DEGREES=C6/TEMPERAURE --
/FORECAST
use strict;
use warnings;
use XML::Parser;
my %forecast;
my @curr;
my $type;
my $p1 = new XML::Parser(Style = 'Stream');
my $yahoo = shift;
$p1-parsefile($yahoo);
print Outlook: $forecast{outlook}\n;
foreach (keys %forecast) {
next if /outlook/;
print $_: $forecast{$_}-{val} $forecast{$_}-{deg}\n;
}
sub StartTag {
my ($p, $tag) = @_;
push @curr, $tag;
if ($tag eq 'TEMPERATURE') {
$type = $_{TYPE};
$forecast{$type}-{deg} = $_{DEGREES};
}
}
sub EndTag {
pop @curr;
}
sub Text {
my ($p) = shift;
return unless /\S/;
s/^\s+//;
s/^\s+$//;
if ($curr[-1] eq 'OUTLOOK') {
$forecast{outlook} .= $_;
} elsif ( $curr[-1] eq 'TEMPERATURE' ) {
$forecast{$type}-{val} = $_;
}
}
sorry, just saw the typo on xml file
?xml version='1.0' ?
FORECAST
OUTLOOKPartly Cloudy\OUTLOOK --- typo here
TEMPERATURE TYPE=MAX DEGREES=C12/TEMPERATURE
!-- TEMPERATURE TYPE=MIN DEGREES=C6/TEMPERAURE --
/FORECAST
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Re: trying to parse out the simple xml file from the book with XML::Pa
Jeff Pang wrote:
I didn't see you assign a value to %forecast but you can loop through it,why?
- Original Message -
From: Richard Lee
To: Perl Beginners
Subject: trying to parse out the simple xml file from the book with XML::Parser
and I get not well-formed error
Date: 2008-11-3 09:48:05
use strict;
use warnings;
use XML::Parser;
my %forecast;
my @curr;
my $type;
my $p1 = new XML::Parser(Style = 'Stream');
my $yahoo = shift;
$p1-parsefile($yahoo);
print Outlook: $forecast{outlook}\n;
foreach (keys %forecast) {
next if /outlook/;
print $_: $forecast{$_}-{val} $forecast{$_}-{deg}\n;
}
---
??(http://space.sina.com.cn/ )
I am not sure if you got the entire code but after the loop through,
there are more codes which when it encounters tags, it builds %forecast
hash as below
sub StartTag {
my ($p, $tag) = @_;
push @curr, $tag;
if ($tag eq 'TEMPERATURE') {
$type = $_{TYPE};
$forecast{$type}-{deg} = $_{DEGREES};
}
}
sub EndTag {
pop @curr;
}
sub Text {
my ($p) = shift;
return unless /\S/;
s/^\s+//;
s/^\s+$//;
if ($curr[-1] eq 'OUTLOOK') {
$forecast{outlook} .= $_;
} elsif ( $curr[-1] eq 'TEMPERATURE' ) {
$forecast{$type}-{val} = $_;
}
}
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confused about reference
I was just testing some reference and while trying out below I am trying
to understand below
@{$yahoo-{yahoo}}... I can see that this is pointing to 0,1,3
by running the code.
But I am trying to really understand whether this is trying to say since
value of 'yahoo' is array put @ at the front?
or @ is there because it's array slice??
Can someone explain this?
Also, %{$base[0]}, trying to understand this.
According to the tutorial,
%base referenced is %{$base}
what is the difference between %{$base[0]} vs %{$base}[0]
Are we here talking about first being hash reference which first item
is array reference vs second one is hash reference's first item ?
thank you.
#!/usr/bin/perl
use warnings;
use strict;
use Data::Dumper;
my $yahoo = { 'yahoo' = [ 0, 1, 3],
'msn' = [ 12, 32, 44]
};
print Dumper($yahoo);
print
\n\n\n\n\n\n;
print ${$yahoo}{yahoo}[0]\n; # prints 0
print $yahoo-{yahoo}[0]\n;# prints 0
print @{$yahoo-{yahoo}}\n;# prints 0,1,3
print %{$yahoo-{yahoo}}\n;# print %{ARRAY(0x832e8c4)}
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Re: confused about reference
Richard Lee wrote:
I was just testing some reference and while trying out below I am
trying to understand below
@{$yahoo-{yahoo}}... I can see that this is pointing to
0,1,3 by running the code.
But I am trying to really understand whether this is trying to say
since value of 'yahoo' is array put @ at the front?
or @ is there because it's array slice??
Can someone explain this?
@{$yahoo-{yahoo}} has @ on it because it's value of yahoo is
reference. Is this right?
Also, %{$base[0]}, trying to understand this.
According to the tutorial,
%base referenced is %{$base}
what is the difference between %{$base[0]} vs %{$base}[0] Are we
here talking about first being hash reference which first item is
array reference vs second one is hash reference's first item ?
This one, I cannot figure it out
thank you.
#!/usr/bin/perl
use warnings;
use strict;
use Data::Dumper;
my $yahoo = { 'yahoo' = [ 0, 1, 3],
'msn' = [ 12, 32, 44]
};
print Dumper($yahoo);
print
\n\n\n\n\n\n;
print ${$yahoo}{yahoo}[0]\n; # prints 0
print $yahoo-{yahoo}[0]\n;# prints 0
print @{$yahoo-{yahoo}}\n;# prints 0,1,3
print %{$yahoo-{yahoo}}\n;# print %{ARRAY(0x832e8c4)}
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Re: XML::Simple question
Rob Dixon wrote:
Richard Lee wrote:
while trying to study the article on perlmonks.org,
http://perlmonks.org/?node_id=490846
regarding XML parsing, I need bit of clarfication.
how do I parse out
image src=http://www.oreilly.com/catalog/covers/perlbp.s.gif;
width=145 height=190 /
I tried $book-{image}-{src}... but doesn't work.. I need some
understanding on how these information is stored.
parsing code
use XML::Simple qw(:strict);
my $library = XMLin($filename,
ForceArray = 1,
KeyAttr= {},
);
foreach my $book (@{$library-{book}}) {
print $book-{title}-[0], \n
}
XML file
library
book
titlePerl Best Practices/title
authorDamian Conway/author
isbn0596001738/isbn
pages542/pages
image src=http://www.oreilly.com/catalog/covers/perlbp.s.gif;
width=145 height=190 /
/book
book
titlePerl Cookbook, Second Edition/title
authorTom Christiansen/author
authorNathan Torkington/author
isbn0596003137/isbn
pages964/pages
image src=http://www.oreilly.com/catalog/covers/perlckbk2.s.gi
+f
width=145 height=190 /
/book
book
titleGuitar for Dummies/title
authorMark Phillips/author
authorJohn Chappell/author
isbn076455106X/isbn
pages392/pages
image src=http://media.wiley.com/product_data/coverImage/6X/07
+645510/076455106X.jpg
width=100 height=125 /
/book
/library
I agree with Stewart that XML::Simple is far from simple in practice. For the
selection of options for XMLin you have used, you can access the image data like
this:
foreach my $book (@{$library-{book}}) {
my $title = $book-{title}[0];
my $image = $book-{image}[0];
print $title\n;
print $image-{src}\n;
print $image-{width}\n;
print $image-{height}\n;
}
but the structure of the data will change depending on what options are set, and
in general it is very difficult to use XML::Simple without also using
Data::Dumper to inspect the data structure that has actually been generated.
HTH,
Rob
thanks all!
Will try few others now.
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XML::Simple question
while trying to study the article on perlmonks.org,
http://perlmonks.org/?node_id=490846
regarding XML parsing, I need bit of clarfication.
how do I parse out
image src=http://www.oreilly.com/catalog/covers/perlbp.s.gif;
width=145 height=190 /
I tried $book-{image}-{src}... but doesn't work.. I need some
understanding on how these information is stored.
parsing code
use XML::Simple qw(:strict);
my $library = XMLin($filename,
ForceArray = 1,
KeyAttr= {},
);
foreach my $book (@{$library-{book}}) {
print $book-{title}-[0], \n
}
XML file
library
book
titlePerl Best Practices/title
authorDamian Conway/author
isbn0596001738/isbn
pages542/pages
image src=http://www.oreilly.com/catalog/covers/perlbp.s.gif;
width=145 height=190 /
/book
book
titlePerl Cookbook, Second Edition/title
authorTom Christiansen/author
authorNathan Torkington/author
isbn0596003137/isbn
pages964/pages
image src=http://www.oreilly.com/catalog/covers/perlckbk2.s.gi
+f
width=145 height=190 /
/book
book
titleGuitar for Dummies/title
authorMark Phillips/author
authorJohn Chappell/author
isbn076455106X/isbn
pages392/pages
image src=http://media.wiley.com/product_data/coverImage/6X/07
+645510/076455106X.jpg
width=100 height=125 /
/book
/library
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Please help me w/ my sub
below sub works fine except the line where key is default.
Instead of printing out PCMU only once, it's printing it out 40 times
randomly..
Trying to figure out what I did wrong.
Please leave me a feedback.
thank you.
156 time(s) Codec(s) : unassigned_38
185 time(s) Codec(s) : G729
1966 time(s) Codec(s) : PCMUPCMUPCMUPCMU
PCMUPCMUPCMUPCMUPCMUPCMU
PCMUPCMUPCMUPCMUPCMUPCMU
PCMUPCMUPCMUPCMUPCMUPCMU
PCMUPCMUPCMUPCMUPCMUPCMU
PCMUPCMUPCMUPCMUPCMUPCMU
PCMUPCMUPCMUPCMUPCMUPCMU
sub codec_list {
#my @codec_d = qw/0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
19 20 21 22 23 24 25 26 27
# 28 29 30 31 32 33 34 35--71 72--76 77--95 96--127/;
my @codec_d = qw/0 default 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
17 18 19 20 21 22 23 24 25 26 27
28 29 30 31 32 33 34 A B C D/;
my @codec_i = qw/PCMU PCMU Reserved Reserved GSM G723 DVI4 DVI4
LPC PCMA G722 L16 L16 QCELP CN MAP
G728 DVI4 DVI4 G729 reserved unassigned
unassigned unassigned unassigned unassigned
CelB JPEG unassigned nv unassigned unassigned
H261 MPV MP2T H263
unassigned reserved unassigned dynamic/;
my %codec_r;
my @return_codec;
@[EMAIL PROTECTED] = (@codec_i);
my $number = shift;
HS: for ( @$number ) {
my $request_key = $_;
#next unless $request_key =~ /^\d+$/;
for my $o ( keys %codec_r ) {
if ( $request_key eq $o ) {
push @return_codec, $codec_r{$o};
} elsif ( $request_key eq 'default' ) {
push @return_codec, $codec_r{'default'}; ---
problem line
} elsif ( ($o =~ /A|B|C|D/ ) ) {
if ( ( $request_key = 35 ) and ( $request_key =
71 )) {
push @return_codec, join ('_' , $codec_r{'A'},
$request_key );
next HS;
} elsif ( ( $request_key = '72' ) and (
$request_key = '76' )) {
push @return_codec, $codec_r{'B'};
next HS;
} elsif ( ( $request_key = '77' ) and (
$request_key = '95' )) {
push @return_codec, $codec_r{'C'};
next HS;
} elsif ( ( $request_key = '96' ) and (
$request_key = '126' )) {
push @return_codec, $codec_r{'D'};
next HS;
}
}
}
}
return @return_codec;
}
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Re: Please help me w/ my sub
John, I think this is now fixed.
Still looking to make sure its covering all basis..
sub codec_list {
#my @codec_d = qw/0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
19 20 21 22 23 24 25 26 27
# 28 29 30 31 32 33 34 35--71 72--76 77--95 96--127/;
my @codec_d = qw/0 default 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
17 18 19 20 21 22 23 24 25 26 27
28 29 30 31 32 33 34 A B C D/;
my @codec_i = qw/PCMU PCMU Reserved Reserved GSM G723 DVI4 DVI4
LPC PCMA G722 L16 L16 QCELP CN MAP
G728 DVI4 DVI4 G729 reserved unassigned
unassigned unassigned unassigned unassigned
CelB JPEG unassigned nv unassigned unassigned
H261 MPV MP2T H263
unassigned reserved unassigned dynamic/;
my %codec_r;
my @return_codec;
@[EMAIL PROTECTED] = (@codec_i);
my $number = shift;
HS: for ( @$number ) {
my $request_key = $_;
#next unless $request_key =~ /^\d+$/;
for my $o ( keys %codec_r ) {
if ( $request_key eq $o ) { # if
item from array ref @number matches one of the key in %codec_r
push @return_codec, $codec_r{$o};
next HS;
} elsif ( $request_key eq 'default' ) {
push @return_codec, $codec_r{'default'};
next HS;
} elsif ( ($o =~ /A|B|C|D/ ) ) {
if ( ( $request_key = 35 ) and ( $request_key =
71 )) {
push @return_codec, join ('_' , $codec_r{'A'},
$request_key );
next HS;
} elsif ( ( $request_key = '72' ) and (
$request_key = '76' )) {
push @return_codec, join ('_' , $codec_r{'B'},
$request_key ) ;
next HS;
} elsif ( ( $request_key = '77' ) and (
$request_key = '95' )) {
push @return_codec, join ('_', $codec_r{'C'},
$request_key ) ;
next HS;
} elsif ( ( $request_key = '96' ) and (
$request_key = '126' )) {
push @return_codec, join ('_', $codec_r{'D'},
$request_key ) ;
next HS;
}
} else {
next;
}
}
}
return @return_codec;
}
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Re: Please help me w/ my sub
Chas. Owens wrote:
On Tue, Oct 14, 2008 at 02:15, Richard Lee [EMAIL PROTECTED] wrote:
below sub works fine except the line where key is default.
Instead of printing out PCMU only once, it's printing it out 40 times
randomly..
Trying to figure out what I did wrong.
snip
I found your code to be very odd. You do not normally loop over the
keys in a hash to determine if there is a match; you just ask the hash
if a match occurred. Did your code start out using the arrays at the
top instead of a hash? I have rewritten your function to make better
use of the hash and provide error handling for out of range requests.
The error was in your looping code (the default case was being
executed for every key in the hash).
#!/usr/bin/perl
use strict;
use warnings;
$|=1;
for my $request (qw/default A B C D/, 0 .. 126) {
print codec_list([$request]), \n,
}
print join(, , codec_list([0 .. 126])), \n;
codec_list([-1, 128]);
sub codec_list {
my $number = shift;
#FIXME: this should really be in a file
my @codec_d = qw/0 default 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 A B C D/;
my @codec_i = qw/PCMU PCMU Reserved Reserved GSM G723 DVI4 DVI4 LPC
PCMA G722 L16 L16 QCELP CN MAP G728 DVI4 DVI4 G729 reserved unassigned
unassigned unassigned unassigned unassigned CelB JPEG unassigned nv
unassigned unassigned H261 MPV MP2T H263 unassigned reserved
unassigned dynamic/;
my %codec_r;
@[EMAIL PROTECTED] = (@codec_i);
$codec_r{$_} = $codec_r{A}_$_ for 35 .. 71;
@codec_r{72 .. 76} = ($codec_r{B}) x ( 77 - 72);
@codec_r{77 .. 95} = ($codec_r{C}) x ( 96 - 77);
@codec_r{96 .. 126} = ($codec_r{D}) x (127 - 96);
my $errors = 0;
my @return_codec;
for my $request_key ( @$number ) {
if (exists $codec_r{$request_key}) {
push @return_codec, $codec_r{$request_key};
next;
} else {
warn $request_key is not valid;
$errors++;
}
}
die had $errors errors if $errors;
return @return_codec;
}
--
Chas. Owens
wonkden.net
The most important skill a programmer can have is the ability to read.
thank you. I am heading to work.. will review and comment back.
thanks again!
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Re: Please help me w/ my sub
Chas. Owens wrote:
On Tue, Oct 14, 2008 at 02:15, Richard Lee [EMAIL PROTECTED] wrote:
below sub works fine except the line where key is default.
Instead of printing out PCMU only once, it's printing it out 40 times
randomly..
Trying to figure out what I did wrong.
snip
I found your code to be very odd. You do not normally loop over the
keys in a hash to determine if there is a match; you just ask the hash
if a match occurred. Did your code start out using the arrays at the
top instead of a hash? I have rewritten your function to make better
use of the hash and provide error handling for out of range requests.
The error was in your looping code (the default case was being
executed for every key in the hash).
#!/usr/bin/perl
use strict;
use warnings;
$|=1;
for my $request (qw/default A B C D/, 0 .. 126) {
print codec_list([$request]), \n,
}
print join(, , codec_list([0 .. 126])), \n;
codec_list([-1, 128]);
sub codec_list {
my $number = shift;
#FIXME: this should really be in a file
my @codec_d = qw/0 default 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 A B C D/;
my @codec_i = qw/PCMU PCMU Reserved Reserved GSM G723 DVI4 DVI4 LPC
PCMA G722 L16 L16 QCELP CN MAP G728 DVI4 DVI4 G729 reserved unassigned
unassigned unassigned unassigned unassigned CelB JPEG unassigned nv
unassigned unassigned H261 MPV MP2T H263 unassigned reserved
unassigned dynamic/;
my %codec_r;
@[EMAIL PROTECTED] = (@codec_i);
$codec_r{$_} = $codec_r{A}_$_ for 35 .. 71;
@codec_r{72 .. 76} = ($codec_r{B}) x ( 77 - 72);
@codec_r{77 .. 95} = ($codec_r{C}) x ( 96 - 77);
@codec_r{96 .. 126} = ($codec_r{D}) x (127 - 96);
my $errors = 0;
my @return_codec;
for my $request_key ( @$number ) {
if (exists $codec_r{$request_key}) {
push @return_codec, $codec_r{$request_key};
next;
} else {
warn $request_key is not valid;
$errors++;
}
}
die had $errors errors if $errors;
return @return_codec;
}
--
Chas. Owens
wonkden.net
The most important skill a programmer can have is the ability to read.
your work put my code to shame..
But it is excellent and I am reviewing and trying to understand your
code so that I can re-incorporate them into my program..
will let you know..
thanks.
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Re: Please help me w/ my sub
John W. Krahn wrote:
Richard Lee wrote:
below sub works fine except the line where key is default.
Instead of printing out PCMU only once, it's printing it out 40 times
randomly..
Trying to figure out what I did wrong.
Please leave me a feedback.
thank you.
156 time(s) Codec(s) : unassigned_38
185 time(s) Codec(s) : G729 1966 time(s) Codec(s) :
PCMUPCMUPCMUPCMUPCMU
PCMUPCMUPCMUPCMUPCMU
PCMUPCMUPCMUPCMUPCMU
PCMUPCMUPCMUPCMUPCMU
PCMUPCMUPCMUPCMUPCMU
PCMUPCMUPCMUPCMUPCMU
PCMUPCMUPCMUPCMUPCMU
PCMUPCMUPCMUPCMUPCMU
sub codec_list {
#my @codec_d = qw/0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
19 20 21 22 23 24 25 26 27
# 28 29 30 31 32 33 34 35--71 72--76 77--95
96--127/;
my @codec_d = qw/0 default 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
16 17 18 19 20 21 22 23 24 25 26 27
28 29 30 31 32 33 34 A B C D/;
my @codec_i = qw/PCMU PCMU Reserved Reserved GSM G723 DVI4 DVI4
LPC PCMA G722 L16 L16 QCELP CN MAP
G728 DVI4 DVI4 G729 reserved unassigned
unassigned unassigned unassigned unassigned
CelB JPEG unassigned nv unassigned unassigned
H261 MPV MP2T H263
unassigned reserved unassigned dynamic/;
my %codec_r;
my @return_codec;
@[EMAIL PROTECTED] = (@codec_i);
my $number = shift;
HS: for ( @$number ) {
my $request_key = $_;
#next unless $request_key =~ /^\d+$/;
for my $o ( keys %codec_r ) {
if ( $request_key eq $o ) {push
@return_codec, $codec_r{$o};
} elsif ( $request_key eq 'default' ) {
Your problem is that neither $request_key nor 'default' changes in the
inner loop so $codec_r{'default'} is added for every element of
@codec_d. You probably want to put next HS; after the push().
push @return_codec, $codec_r{'default'}; ---
problem line
} elsif ( ($o =~ /A|B|C|D/ ) ) {
if ( ( $request_key = 35 ) and ( $request_key =
71 )) {
push @return_codec, join ('_' ,
$codec_r{'A'}, $request_key );
next HS;
} elsif ( ( $request_key = '72' ) and (
$request_key = '76' )) {
Why are you using numerical comparison on strings:
} elsif ( $request_key = 72 $request_key =
76 ) {
push @return_codec, $codec_r{'B'};
next HS;
} elsif ( ( $request_key = '77' ) and (
$request_key = '95' )) {
} elsif ( $request_key = 77 $request_key =
95 ) {
push @return_codec, $codec_r{'C'};
next HS;
} elsif ( ( $request_key = '96' ) and (
$request_key = '126' )) {
} elsif ( $request_key = 96 $request_key =
126 ) {
push @return_codec, $codec_r{'D'};
next HS;
}} } }
return @return_codec;
}
John
thanks John, that was the problem. (HS solution).
Why are you using numerical comparison on strings:
} elsif ( $request_key = 72 $request_key = 76 ) {
-- I see the flaw in my design.. I am going back to see if I can fix it..
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array serach for partial value
Hello, I have small Perl project and got stuck on following problem : There is a zip file with bunch of files in it. I need to search through it and find if every xxx.txt file has xxx.log pair and list all of those .txt without pairs. I figured out that I will use Archive::Zip and iterate through members of the zip then copy all compressed file names into an array and then search array for those pairs. But since my knowledge of perl is rather weak i can't figure out how to search through array for only part of the value (xxx. in this case...) Can you help me guys with that problem ? Thanks a lot... Richard -- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] http://learn.perl.org/
sub and return question
can't you do below??
sub criteria {
return qw/ 1,3,5,7,9 /;
}
I was going to do
sub criteria {
my @array = qw/1,3,5,7,9/;
}
but was wondering if I can do without if i was calling the sub like this
my @array_result = criteria();
??
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Re: sub and return question
Richard Lee wrote:
can't you do below??
sub criteria {
return qw/ 1,3,5,7,9 /;
}
I was going to do
sub criteria {
my @array = qw/1,3,5,7,9/;
}
but was wondering if I can do without if i was calling the sub like this
my @array_result = criteria();
??
actually qw/ 1 3 5 7 9/; i was wrongly adding commas there.. sorry abou
thtis post.. disregard please.
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Re: sub and return question
Mr. Shawn H. Corey wrote:
Don't use commas inside a qw
#!/usr/bin/perl
use strict;
use warnings;
use Data::Dumper;
$Data::Dumper::Sortkeys = 1;
$Data::Dumper::Indent = 1;
$Data::Dumper::Maxdepth = 0;
sub criteria {
return qw/ 1 3 5 7 9 /;
}
my @array_result = criteria();
print Dumper [EMAIL PROTECTED];
__END__
yes, thank you!
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Re: a perl blog (perlbuzz)
Jeff Pang wrote: I don't know if everybody here know it yet, but I just give a recommendation. http://perlbuzz.com/ It has some good and updated articles there. Regards, Jeff. Créez votre adresse électronique [EMAIL PROTECTED] 1 Go d'espace de stockage, anti-spam et anti-virus intégrés. links to the perl journal alone made this post my day. thank you!!! -- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] http://learn.perl.org/
reference question
one more question on reference,
if say you have sub as below
my @arrayref;
sub do_something {
my $something = @_;
open FILE, $something, or die;
while (FILE) {
my @array = map (split /,/)[1,2,3,5];
push @arrayref, [EMAIL PROTECTED];
}
close FILE;
}
my @arrayref_copy = do_something($something);
Let's for a moment forget about my inefficient style and just look at
the last step.
If I wanted to use @arrayref_copy and pass it into another
subroutine,should I reference them again?(if file itself was pretty big?)
another_sub([EMAIL PROTECTED]); -- is this the right thing to do? or is
this redundant since array is already collection of reference?
sub another_sub {
}
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Re: reference question
Rob Dixon wrote:
Richard Lee wrote:
one more question on reference,
if say you have sub as below
Your code is badly wrong. Please let me correct it first.
my @arrayref;
sub do_something {
my $something = @_;
That will set $something to the number of parameters passed in @_
To retrieve the first parameter you should write
my ($something) = @_;
or
my $something = shift;
open FILE, $something, or die;
You should not quote scalar variables unless you know what it does and have a
reason to do it. Also the it is far better and safer to use lexical file handles
and the three-parameter form of open, and you should incorporate the $! variable
into the die string so that it is clear why the open has failed.
open my $file, '', $something or die $!;
while (FILE) {
while ($file) {
if you are using my proposed change.
my @array = map (split /,/)[1,2,3,5];
That will probably not compile. You are calling
map(split /,/)
and map requires either a block or an expression as its first parameter,
followed by a list to map. You mean simply
my @array = (split /,/)[1,2,3,5];
push @arrayref, [EMAIL PROTECTED];
}
close FILE;
If you use a lexical file handle $file then it will be closed implicitly when it
goes out of scope at the end of the subroutine. There is no need for an explicit
call to close.
}
my @arrayref_copy = do_something($something);
Let's for a moment forget about my inefficient style and just look at
the last step. If I wanted to use @arrayref_copy and pass it into another
subroutine,should I reference them again?(if file itself was pretty big?)
another_sub([EMAIL PROTECTED]); -- is this the right thing to do? or is
this redundant since array is already collection of reference?
sub another_sub {
}
Yes that would be fine. It helps because you're not copying all the references
to a second list. But I would go a step further and pass it back from the first
subroutine as a reference to an array. Like this
sub read_file {
my $name = shift;
open my $fh, '', $name or die $!;
my @data;
while ($fh) {
my @record = (split /,/)[1, 2, 3, 5];
push @data, [EMAIL PROTECTED];
}
return [EMAIL PROTECTED];
}
and then you can write
my $data = read_file('filename');
my $result = another_sub($data);
and so on.
HTH,
Rob
This is great explanation.. thank you. I will re-read this to see if I
can correct and manipulate my original program.
thank you.
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from perl review (first article) question on regex
I was reading perl magazine and saw
sub readable {
my $number = shift;
$matched = $number =~ s{
(\d+)
(\d{3})
(,|$)
}{$1,$2$3}x;
} while ($matched);
return $number;
}
on test driven development article by Denis Kosykh.
I am not sure what
(,|$) is doing...
Can someone please explain?
thank you.
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can perl program do this?
say I have big wireshark file based on remote server. I want to logon to that server and using Net::Pcap to poke the file and only grep out small portion of information which meets my criteria. Remote server won't have Net::Pcap installed. I wanted to write this program w/ Expect modules and Net::Pcap module in my mind. But since these things are only located in my local server, will this work on remote server? -- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] http://learn.perl.org/
Re: can perl program do this?
Rob Coops wrote: If you can make Net::Pcap connect to a remote server things will work fine, I am not sure about using Net::Pcap to do this as I never used it and from the description it seems to be a packet capture lib not so much a communication one, but as I said if you can make it reach out and talk to the other side you should be fine. I think you will end up using somehting like Net::SSH or something like that as these are more aimed at communication then Net::Pcap seems to be. But in the end as long as the other side is listening on a port and you can produce the required packets to get communication going you should be fine, there is no need to have perl, or any perl libs on the other side all that is needed is an open port that you can communicate with. The thing that is listening on that port is what determins what you can do, read email, open and interact with files or just browse a web page, perl on your machine cannot change which process is listening on the other machine. In short I guess you can if the other machine is listening, but you might want to use a more suitable lib for it. Regards, Rob On Thu, Jul 31, 2008 at 8:41 AM, Richard Lee [EMAIL PROTECTED] mailto:[EMAIL PROTECTED] wrote: say I have big wireshark file based on remote server. I want to logon to that server and using Net::Pcap to poke the file and only grep out small portion of information which meets my criteria. Remote server won't have Net::Pcap installed. I wanted to write this program w/ Expect modules and Net::Pcap module in my mind. But since these things are only located in my local server, will this work on remote server? -- To unsubscribe, e-mail: [EMAIL PROTECTED] mailto:[EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] mailto:[EMAIL PROTECTED] http://learn.perl.org/ Hi, local server(w/ Perl installed) --- remote server(with Pcap file I am interested in poking around) if I launch a perl script from my local server(using say Net::SSH) and logs onto remote server, my perl can poke around that file on remote server using Net::Pcap ? So essentially in order to do this, I need to use 2 modules(to logon, and then parsing out the pcap file) I am thinking about writing this but just not sure if it will work on remote server -- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] http://learn.perl.org/
Re: can perl program do this?
Rob Coops wrote: Ah, I see... I think you have been misled by the name of the Net::Pcap lib, the lib is meant to produce the file you are trying to poke around in. I would do the follwoing. * Use Net::SSH or similair to connect to the remote machine. * On the remote machine use grep or similair to pull out the lines you are intrested in and store those in an array/file or well what ever storage you like on your side. * Process the data on your own machine. The advantage of this is that you only move the data you are intrested in over the network and not the whole big file, thus reducing the network trafic and maning your network admins happy as well. Because you have the data on your side you can then do with it what you want without having to rely on any software on the remote machine. I hope this helps a bit, Rob On Thu, Jul 31, 2008 at 9:06 AM, Richard Lee [EMAIL PROTECTED] mailto:[EMAIL PROTECTED] wrote: Rob Coops wrote: If you can make Net::Pcap connect to a remote server things will work fine, I am not sure about using Net::Pcap to do this as I never used it and from the description it seems to be a packet capture lib not so much a communication one, but as I said if you can make it reach out and talk to the other side you should be fine. I think you will end up using somehting like Net::SSH or something like that as these are more aimed at communication then Net::Pcap seems to be. But in the end as long as the other side is listening on a port and you can produce the required packets to get communication going you should be fine, there is no need to have perl, or any perl libs on the other side all that is needed is an open port that you can communicate with. The thing that is listening on that port is what determins what you can do, read email, open and interact with files or just browse a web page, perl on your machine cannot change which process is listening on the other machine. In short I guess you can if the other machine is listening, but you might want to use a more suitable lib for it. Regards, Rob On Thu, Jul 31, 2008 at 8:41 AM, Richard Lee [EMAIL PROTECTED] mailto:[EMAIL PROTECTED] mailto:[EMAIL PROTECTED] mailto:[EMAIL PROTECTED] wrote: say I have big wireshark file based on remote server. I want to logon to that server and using Net::Pcap to poke the file and only grep out small portion of information which meets my criteria. Remote server won't have Net::Pcap installed. I wanted to write this program w/ Expect modules and Net::Pcap module in my mind. But since these things are only located in my local server, will this work on remote server? --To unsubscribe, e-mail: [EMAIL PROTECTED] mailto:[EMAIL PROTECTED] mailto:[EMAIL PROTECTED] mailto:[EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] mailto:[EMAIL PROTECTED] mailto:[EMAIL PROTECTED] mailto:[EMAIL PROTECTED] http://learn.perl.org/ Hi, local server(w/ Perl installed) --- remote server(with Pcap file I am interested in poking around) if I launch a perl script from my local server(using say Net::SSH) and logs onto remote server, my perl can poke around that file on remote server using Net::Pcap ? So essentially in order to do this, I need to use 2 modules(to logon, and then parsing out the pcap file) I am thinking about writing this but just not sure if it will work on remote server but I am interested in grepping out the pcap file so I cannot simply just do grep -- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] http://learn.perl.org/
Re: Pipe print output into shell in debugger
Marek wrote: Hello all, while being in the debugger, how do I pipe all printings going to a OUTputfile like: print OUT text text text; into the shell? I read perldebug and perldebguts, but probably I just overread it? Thank you for your help marek I am sure there are other ways to do this but I always wonder how to get this done. Many research and I found that I could have | (pipe) precede your command and output will go to your pager. I am just not sure how to change the pager on my system(mine is less, and if you can change to vi, you should be able to save it). Let me know if you are able to change your pager.. (I am not sure if pager they mean editor or something else in your environment, I use bash ). -- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] http://learn.perl.org/
Re: while trying to learn pack
John W. Krahn wrote: Richard Lee wrote: I am begining to read bit of low level(assembly) book to just gain some knoweldge on inner workings of memory. My quesiton is, if machine is 32 bit, even if it's accessing string 'A', it will have to fetch 32 bit (instead of 8 bit that requires to make that letter A ) ? It depends on the CPU. An Intel compatible CPU has instructions to access 8 bit values from memory but some CPUs can only access 32 bit aligned data. I know this is not a mailing list for this but i figure since it's closely related to pack, i thought someone would clarify for me. It is not really related to pack() as pack() is a high level function that can hide the details of the CPUs addressing problems. I am reading step by step assembly language... I am not sure i will read the whole thing but i just want to get better inner working of memory as my c book didn't do enough justice. John thanks guys Just one more question on the topic, I am trying to understand how it works in binary world. So, If let's say I take a pcap file. I am assuming here that ethereal/wireshark will take binaries on the wire and then decoding it based on pcap standard(? hex? ) and then present them in ascci ? so which means in order to unpack pcap file, I have to know how ethereal pack on their own.. is this something similar to what happens when pcap file gets created? -- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] http://learn.perl.org/
Re: while trying to learn pack
John W. Krahn wrote: Richard Lee wrote: I am begining to read bit of low level(assembly) book to just gain some knoweldge on inner workings of memory. My quesiton is, if machine is 32 bit, even if it's accessing string 'A', it will have to fetch 32 bit (instead of 8 bit that requires to make that letter A ) ? It depends on the CPU. An Intel compatible CPU has instructions to access 8 bit values from memory but some CPUs can only access 32 bit aligned data. I know this is not a mailing list for this but i figure since it's closely related to pack, i thought someone would clarify for me. It is not really related to pack() as pack() is a high level function that can hide the details of the CPUs addressing problems. I am reading step by step assembly language... I am not sure i will read the whole thing but i just want to get better inner working of memory as my c book didn't do enough justice. John Thanks guys, One more question, How do I look at binary file using perl? ( I am assuming unpack will be able to handle it ). I am trying to see if I can peak into pcap file w/ unpack... what will require? ( I am trying to not use modules to learn ) Idea is to learn the pcap structure and use it to unpack somehow? I am not asking for anything specific in order to solve the problem. I guess just reaching out for general idea. if that's possible. Meanwhile I will keep reading. thanks for help!! -- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] http://learn.perl.org/
while trying to learn pack
I am begining to read bit of low level(assembly) book to just gain some knoweldge on inner workings of memory. My quesiton is, if machine is 32 bit, even if it's accessing string 'A', it will have to fetch 32 bit (instead of 8 bit that requires to make that letter A ) ? I know this is not a mailing list for this but i figure since it's closely related to pack, i thought someone would clarify for me. I am reading step by step assembly language... I am not sure i will read the whole thing but i just want to get better inner working of memory as my c book didn't do enough justice. Please help. thanks! -- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] http://learn.perl.org/
perlpacktut ... not sure what I am doing wrong while following the example.. Explanation please
just trying to learn pack/unpack function in perl..
http://perldoc.perl.org/perlpacktut.html
I thought i followed pretty much to the teeth from the tutorial itself
and when I type them into my linux box , it didn't exactly work the way
I expected them to.. What am I doing wrong?
[EMAIL PROTECTED] ~]# cat -A pack_test2.pl
#!/usr/bin/perl$
$
use strict;$
use warnings;$
$
my $tot_income;$
my $tot_expend;$
use POSIX;$
$
my $date = POSIX::strftime(%m/%d/%Y, localtime);$
$
while (DATA) {$
my($date, $desc, $income, $expend) = unpack(A10 A27 A7 A*, $_);$
$tot_income += $income;$
$tot_expend += $expend;$
print_this($tot_income,$tot_expend);$
}$
$
sub print_this {$
my($tot_income,$tot_expend) = @_;$
$tot_income = sprintf(%.2f, $tot_income); # Get them into $
$tot_expend = sprintf(%.2f, $tot_expend); # financial format$
print pack(A10 A27 A7 A*, $date, Totals, $tot_income,
$tot_expend);$
}$
$
__END__$
01/24/2001 Ahmed's Camel Emporium 1147.99$
01/28/2001 Flea spray24.99$
01/29/2001 Camel rides to tourists 235.00$
But it's not working out well..
[EMAIL PROTECTED] ~]# ./!$
./././././././pack_test2.pl
Argument isn't numeric in addition (+) at ./././././././pack_test2.pl
line 14, DATA line 1.
Argument isn't numeric in addition (+) at ./././././././pack_test2.pl
line 14, DATA line 2.
07/19/2008Totals 0.00
1147.9907/19/2008Totals 0.00
1172.9807/19/2008Totals 235.00 [EMAIL PROTECTED] ~]#
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Re: perlpacktut ... not sure what I am doing wrong while following the example.. Explanation please
John W. Krahn wrote:
Richard Lee wrote:
just trying to learn pack/unpack function in perl..
http://perldoc.perl.org/perlpacktut.html
You *should* have the documentation for Perl installed on your hard
drive which will be more relevant to the version of Perl you are using.
I thought i followed pretty much to the teeth from the tutorial
itself and when I type them into my linux box , it didn't exactly
work the way
I expected them to.. What am I doing wrong?
[EMAIL PROTECTED] ~]# cat -A pack_test2.pl
cat -A? You're really trying to make it difficult to just copy and
run your code?
#!/usr/bin/perl$
$
use strict;$
use warnings;$
$
my $tot_income;$
my $tot_expend;$
use POSIX;$
$
my $date = POSIX::strftime(%m/%d/%Y, localtime);$
$
while (DATA) {$
my($date, $desc, $income, $expend) = unpack(A10 A27 A7 A*, $_);$
Your unpack() format defines the fields as:
01/24/2001 Ahmed's Camel Emporium 1147.99
01/28/2001 Flea spray24.99
01/29/2001 Camel rides to tourists 235.00
^ ^ ^ ^
123456789012345678901234567890123456789012345678901234567890
The second field includes leading whitespace which you don't need.
The third field is not long enough and cuts off the decimal portion of
the number. The fourth field includes the decimal portion from the
third field which in numerical context will be interpreted as the
fourth field instead of the actual fourth field.
You probably want something like this instead:
unpack 'A11 A26 A9 A*', $_;
$tot_income += $income;$
$tot_expend += $expend;$
To suppress the isn't numeric warning you can do this:
$tot_income += $income || 0;
$tot_expend += $expend || 0;
print_this($tot_income,$tot_expend);$
}$
$
sub print_this {$
my($tot_income,$tot_expend) = @_;$
$tot_income = sprintf(%.2f, $tot_income); # Get them into $
$tot_expend = sprintf(%.2f, $tot_expend); # financial format$
print pack(A10 A27 A7 A*, $date, Totals, $tot_income,
$tot_expend);$
And don't forget to add a newline at the end of each output line:
print pack( 'A10 A27 A7 A*', $date, 'Totals', $tot_income,
$tot_expend ), \n;
}$
$
__END__$
01/24/2001 Ahmed's Camel Emporium 1147.99$
01/28/2001 Flea spray24.99$
01/29/2001 Camel rides to tourists 235.00$
But it's not working out well..
[EMAIL PROTECTED] ~]# ./!$
./././././././pack_test2.pl
Argument isn't numeric in addition (+) at
./././././././pack_test2.pl line 14, DATA line 1.
Argument isn't numeric in addition (+) at
./././././././pack_test2.pl line 14, DATA line 2.
07/19/2008Totals 0.00
1147.9907/19/2008Totals 0.00
1172.9807/19/2008Totals 235.00 [EMAIL PROTECTED] ~]#
John
Thanks John and others for explanation. I understand now.
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how do you do this in one step instead of two
is there way to do this in one step? push @array, ($direction, $source); push @hh, [EMAIL PROTECTED] push @hh \($direction,$source) doesn't seem to work.. or not the samething -- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] http://learn.perl.org/
what is wrong w/ this program? (getting undefined value.. but I don't understand) please help
what is wrong w/ below program???
use warnings;
use strict;
use diagnostics;
#open 'PASSWD', '', '/etc/passwd' or die cannot open: $!\n;
open (PASSWD1, /etc/passwd) or die cannot open: $!\n;
my $line;
while ( chomp($line = PASSWD1) ) {
print ---$line---\n if $line =~ /root/;
}
seek(PASSWD1, 0, 0) or die $!\n;
while(PASSWD1) { print if /ellie/;}
close PASSWD1;
Use of uninitialized value in chomp at ./seek_.pl line 11 (#1)
(W uninitialized) An undefined value was used as if it were already
defined. It was interpreted as a or a 0, but maybe it was a mistake.
To suppress this warning assign a defined value to your variables.
To help you figure out what was undefined, perl tells you what operation
you used the undefined value in. Note, however, that perl optimizes
your
program and the operation displayed in the warning may not necessarily
appear literally in your program. For example, that $foo is
usually optimized into that . $foo, and the warning will refer to
the concatenation (.) operator, even though there is no . in your
program.
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Re: what is wrong w/ this program? (getting undefined value.. but I don't understand) please help
Richard Lee wrote:
what is wrong w/ below program???
use warnings;
use strict;
use diagnostics;
#open 'PASSWD', '', '/etc/passwd' or die cannot open: $!\n;
open (PASSWD1, /etc/passwd) or die cannot open: $!\n;
my $line;
while ( chomp($line = PASSWD1) ) {
print ---$line---\n if $line =~ /root/;
}
seek(PASSWD1, 0, 0) or die $!\n;
while(PASSWD1) { print if /ellie/;}
close PASSWD1;
Use of uninitialized value in chomp at ./seek_.pl line 11 (#1)
(W uninitialized) An undefined value was used as if it were already
defined. It was interpreted as a or a 0, but maybe it was a
mistake.
To suppress this warning assign a defined value to your variables.
To help you figure out what was undefined, perl tells you what
operation
you used the undefined value in. Note, however, that perl
optimizes your
program and the operation displayed in the warning may not necessarily
appear literally in your program. For example, that $foo is
usually optimized into that . $foo, and the warning will refer to
the concatenation (.) operator, even though there is no . in your
program.
I found the problem. this new fedora 9 I guess hides the /etc/passwd
file is empty file.
Sorry for the trouble guys.
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Re: what is wrong w/ this program? (getting undefined value.. but I don't understand) please help
John W. Krahn wrote: Or you could do it like this: #!/usr/bin/perl use warnings; use strict; use diagnostics; print '---', join( ':', getpwnam 'root' ), ---\n, join( ':', getpwnam 'ellie' ), \n; __END__ John Thank you for through explanation John as always!! -- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] http://learn.perl.org/
Re: using Expect.pm
was able to make it work but not sure if I am doing the right thing. use warnings; use strict; use Expect; my $exp = new Expect; my $password = 'abc123'; my $user = 'userX'; my $host = '10.3.3.1'; # typical regex pattern for end of /bin/sh prompt: my $shell_prompt = qr/[\$\#]\s*$/; my $login = /usr/bin/ssh [EMAIL PROTECTED]; $exp-spawn($login) or die Can't login to $host as $user: $!\n; ## Enables internal debugging #$exp-exp_internal( 1 ); $exp-log_file(./log_this.txt); $exp-expect(5, '-re', '(RSA)'); my @matchlist = $exp-matchlist; $exp-send(yes\n) if ( ( $exp-matchlist)[0] ); $exp-expect(5, password: ); $exp-send($password\n); $exp-expect(2, -re = $shell_prompt); $exp-send(cat /tmp/file1\n); my @result = $exp-expect(5, -re = $shell_prompt); my $ltedge_now = $result[1]; print \n\n\n $ltedge_now\n; $exp-send(exit\n); $exp-soft_close(); $exp-log_file(undef); -- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] http://learn.perl.org/
using Expect.pm
Hi guys, I was trying to use Expect.pm but it was just too hard for me to capture remote machine's output via below.. #!/usr/bin/perl use warnings; use strict; use Expect; my $exp = new Expect; my $password = 'abc123'; my $user = 'userX'; my $host = '10.3.1.2'; my $login = /usr/bin/ssh [EMAIL PROTECTED]; $exp-spawn($login) or die Can't login to $host as $user: $!\n; ## Enables internal debugging $exp-exp_internal( 1 ); $exp-log_file(./log_this.txt); $exp-expect(5, '-re', '(RSA)'); my @matchlist = $exp-matchlist; $exp-send(yes\n) if ( ( $exp-matchlist)[0] ); $exp-expect(5, password: ); $exp-send($password\n); #my @err = $exp-send(cat /etc/passwd); #print $_\n for @err; $exp-send(exit\n); $exp-log_file(undef); I thought this would capture the output of cat into log file but it does not. I also thought perhaps I can direclty capture it into the array(I have commented them out) but I could not... can someone lead me to the right path? thank you. -- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] http://learn.perl.org/
Re: user id validation
Randal L. Schwartz wrote:
Rajnikant == Rajnikant [EMAIL PROTECTED] writes:
Rajnikant Is there any such way to get home directory of user?
Is there any such way that this might be, perhaps, oh, a FAQ?
Oh, yes, let's see.
$ perldoc -q tilde
Found in /usr/libdata/perl5/pod/perlfaq5.pod
How can I translate tildes (~) in a filename?
Use the (glob()) operator, documented in perlfunc. Older versions of
Perl require that you have a shell installed that groks tildes. Recent
perl versions have this feature built in. The File::KGlob module
(available from CPAN) gives more portable glob functionality.
Within Perl, you may use this directly:
$filename =~ s{
^ ~ # find a leading tilde
( # save this in $1
[^/]# a non-slash character
* # repeated 0 or more times (0 means me)
)
}{
$1
? (getpwnam($1))[7]
: ( $ENV{HOME} || $ENV{LOGDIR} )
}ex;
OK, so you may have not known tilde. But you should be reading
the FAQ titles at least weekly until you are bored to tears from them,
and probably reading the entire FAQ at least bi-monthly.
thanks guys!!
But I guess there is no way to get user id.. ? I will read FAQ more...
(till I am bored to tears ? :-) )
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