Re: Sandboxing while I am learning
Marc wrote: Shawn, if you use perlbrew and local::lib you can test different perl versions and then different environments. I haven't looked into local::lib yet. What advantage does that give you over a plain perlbrew install? Marc I haven't used local::lib very much, because perlbrew seems to be the easiest catch-all solution for my purposes. Once I discovered the --as installation parameter (e.g. perlbrew install 5.14.1 --as perl514_sandbox2, etc.), I had very little use for local::lib. Since perlbrew sets @INC to line up with the --as in each installation, one can create multiple isolated installations of the same Perl version. In my (limited) experience, cpan worked correctly under whichever installation was marked active with perlbrew use (or switch). The downside of this approach is that I'm compiling the same version of Perl multiple times, for the sole purpose of different installation directories. That takes time and hard drive space. So I can see how local::lib may be better if those are critical issues. But for me, adding another ~70MB copy of Perl to my home directory is inconsequential when weighed against the ease of using one tool to do the job. Each to their own. Besides saved disk space and install time, I'd be interested in knowing if I've overlooked some other advantage of local::lib over perlbrew. Brian -- To unsubscribe, e-mail: beginners-unsubscr...@perl.org For additional commands, e-mail: beginners-h...@perl.org http://learn.perl.org/
Re: How to run a perl script in background on Windows?
Jose Marquez wrote: Hi there Sure I am the newbiest of all Perl newbies in this group Just have been reading some of the posts you all have sent since I subscribe to this list What I'm trying to learn these days is how I run a Perl script in background on Windows. Can anybody give a hint on it? Hi Jose, As far as I know, the Windows cmd.exe environment doesn't let you background a process the same way a unix shell does with ''. However, I have used start to achieve a similar effect when launching a script: C:\ start /b perl script.pl Type start /? at a cmd prompt to read about the /B switch. With this switch, you'll still have the cmd.exe window open, but the prompt will return immediately. Also, I use this with Strawberry Perl; I don't know if ActiveState has other tricks you can use. Brian Appreciate very much all the help you guys can provide me Cheers JM -- To unsubscribe, e-mail: beginners-unsubscr...@perl.org For additional commands, e-mail: beginners-h...@perl.org http://learn.perl.org/
Re: using Perl, How to search for files in my computer
Sayth Renshaw wrote:
Try:
my @Music_files = ();
use File::Find;
find( \want_mp3, 'd:\\' );
print $_\n for sort @Music_files;
sub want_mp3 {
push @Music_files, $File::Find::name if $_ =~ /\.mp3$/;
}
--
Just my 0.0002 million dollars worth,
Shawn
Confusion is the first step of understanding.
Programming is as much about organization and communication
as it is about coding.
The secret to great software: Fail early often.
Eliminate software piracy: use only FLOSS.
That was good to see Shawn. I kept working on it but mine was far more
convoluted, and didn't like spaces in directory names.
#!\usr\bin\perl
use warnings;
use strict;
use diagnostics;
use File::List;
use File::Find;
my $mp3;
my @musicFiles;
my $dirList;
my $dir = (c:/);
my @dirList = find(sub {print if -d}, $dir);
# old file line $mp3 = new
File::List(C:/Users/RenshawFamily/maven/Music/Foo Fighters);
foreach $dirList (@dirList) {
@musicFiles = @{ $dirList-find(\.mp3\$) };
}
@musicFiles = sort(@musicFiles);
foreach (@musicFiles)
{
print $_ , \n;
}
Sayth
Hi Sayth, et. al.,
At work I'm stuck on Winblows, and this is one of the ways Strawberry
Perl (portable install) saves me lots of time. There's nothing wrong
with the other solutions presented; I'm just adding to the variety... I
use these one-liners if I need a quick search while playing in DOS
(doesn't sort, just prints as it gets 'em):
perl -MFile::Find -wle find( sub{ /\.mp3$/i and print;}, q(.));
perl -MFile::Find -wle find( sub{ /\.mp3$/i and print
$File::Find::name;}, q(.));
The first I tend to use when I just want an existence check and I
don't need the directory info.
\Brian
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Re: using Perl, How to search for files in my computer
shawn wilson wrote:
On Sun, Jun 12, 2011 at 14:38, Brian F. Yulgabyu...@langly.dyndns.org wrote:
perl -MFile::Find -wle find( sub{ /\.mp3$/i and print;}, q(.));
just curious, what's the difference (in speed or results) between this
and 'dis/a/s/b *.mp3'?
obviously File::Find and perl are more powerful, but that doesn't seem
like the right use case for it?
Hi Shawn,
Good point... For a simple printing of results, 'dir' is noticeably
faster and gives the same results. Actually, before I learned how to
use File::Find, I used to pipe the output from 'dir' to perl to filter
results with a regex:
dir /s /b | perl -wnle /regex/ and print;
...essentially using perl as 'grep', and it's faster than the File::Find
solution (well, I don't have benchmarks to prove it, but File::Find
seemed slower to me). Although in my rather basic uses, the performance
difference is inconsequential, and either way beats using the Windows
Search Companion.
\Brian
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Re: how do i push a hashref into another hashref
Leo Lapworth wrote:
Hi Agnello,
On 7 June 2011 07:47, Agnello Georgeagnello.dso...@gmail.com wrote:
I got the following hashref
snip
now i need to push $select_all_website into $selet_domU_data
I think this is what you want...
use strict;
use warnings;
my $hash_ref_1 = {
a = 1,
b = 2,
};
my $hash_ref_2 = {
a = 3,
c = 4,
};
my $new_hash_ref = {
%{$hash_ref_1},
%{$hash_ref_2}
};
use Data::Dumper;
print Dumper($new_hash_ref);
Which produces:
$VAR1 = {
'c' = 4,
'a' = 3,
'b' = 2
};
Hi Leo,
You are probably close to what the OP wanted; it is hard to read minds
since pushing onto hashes makes no sense. I would call it merging
two hashes. For the OP's data maybe this isn't an issue (and hence why
you didn't state it), but in your sample data, the value for key 'a' in
hash_ref_1 is overwritten by the value in hash_ref_2 during the merge.
Even though your way is short and concise, perhaps it's safer to check
each key before assignment? I suppose the decision to check depends on
the predictability of the source data...
my $combined_hash = { %$hash_ref_1 };
foreach my $key_in_hsh2 ( keys %$hash_ref_2 ) {
if (exists $hash_ref_1-{$key_in_hsh2} ) {
# some algorithm to deal with duplicate keys or alert user
warn found duplicate key '$key_in_hsh2', keeping original
value\n;
} else {
$combined_hash-{$key_in_hsh2} = $hash_ref_2-{$key_in_hsh2}
}
}
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Re: Real Beginner
Tiago Hori wrote: Hey Guys, I am a real beginner so at the risk of being slammed by some, I wanted to get some input. I'm a beginner, too. I've worked through this chapter somewhat recently, so my advice shouldn't be too hard to understand :-) Hopefully _I_ don't get slammed! I was trying to do exercise 5 of the 5th edition of learning perl: You forgot to include Chapter 4 but that's ok, it wasn't hard to find based on the context since I had the book right here :-) I'll snip most of your code to the part that I think may be what's slowing you down. my @peoplec = @people; my $lastperson = shift @peoplec; my $beforelast = shift @peoplec; I think I see what you did, but you can probably make it easier by taking advantage of how 'print' handles arrays as a whole. An example: #!/usr/bin/perl -wl use strict; my @designations = ( 'red', 'two', 'rogue', 'leader' ); print my array contains: @designations; # displays the following # my array contains: red two rogue leader Then you shouldn't have to iterate through each item of the array, or 'shift' off items from a duplicated array. The problem didn't include commas in the output, which (for me), signaled that I could probably just 'print' the entire array at once. ground. I have to say this list is a bit daunting and does not look like a beginners list at all. I think it, as Cat Stevens would say, a wild world out there, but some of us are just trying to get by. That's my view from outside, really outside. I hear ya! Keep trying :-) Brian -- To unsubscribe, e-mail: beginners-unsubscr...@perl.org For additional commands, e-mail: beginners-h...@perl.org http://learn.perl.org/
Re: Nature of this list
Randal L. Schwartz wrote: If they don't have a thick skin already, they'd better get one soon, or they'll be useless as an advanced programmer. Without thick skin, they won't be able to submit their code for review regardless of how much their ego is invested in it. I've been following this list for a few months now, and I've posted a handful of times (both for questions and possible solutions). The first time I ventured some guesses in unknown territory, I got struck down pretty fast. It does kind of suck to spend some time thinking about how things work, post an idea, and then read a you're completely wrong-style, blunt reply. I can see how some newbies could get scared away by this atmosphere, and indeed I have thought twice before posting questions or replying too quickly. But, I have accepted it almost like a Perl initiation trial. I figure, if I stick with it long enough, I can be helped past the newbie level of Perl understanding. Indeed, this list has been an amazing resource for me. Since I'm learning Perl on my own, this list is like a virtual classroom. I enjoy seeing variations on a theme (good and bad), even after a question has been answered, because it gives me insight on how to think about these problems in different ways. If I have to thicken my skin a bit to accept criticism of my code, it's worth it for the knowledge and understanding gained. As a side note, I must confess a slight sense of awe (and much appreciation), that the authors of modules I've used, and even author of two BOOKS I am learning from, are willing to take any amount of time to answer our beginner questions. When I first decided to tackle Perl, I did not expect to have such live expert advice readily available. Since this is a community effort, and the experts aren't getting monetarily compensated for their contributions here, I can understand the tendency toward blunt responses. But it is commendable that some contributors (Shlomi, et.al.) are trying to make the community a little more friendly to newcomers. To be perfectly honest, I'm glad that both camps exist here. It helps in my Perl education, but also prepares me for the real world. I'd much rather have my code ripped apart here on this list, rather than later when it is my entry-level IT job on the line during a code review. I may as well be humbled early on! On the flip side, for the hobbyist programmer, without some hand-holding, they might bail and switch to an easier (or more trendy) language to learn (I don't dare give names ;-) I guess this community has to decide if it wants the list to cater to beginning IT professionals, amateur programming hobbyists, or both. From my newbie perspective, I think this list does a pretty good job with both overall. Even in the context of the current debate, I feel the viewpoints people have contributed to the list are all insightful, and not excessively negative in tone. Shall we all say bygones and move on? ;-) Brian -- To unsubscribe, e-mail: beginners-unsubscr...@perl.org For additional commands, e-mail: beginners-h...@perl.org http://learn.perl.org/
Re: How to test for 2 words from a list in a form field?
shawn wilson wrote:
On Sat, Apr 9, 2011 at 3:29 PM,sono...@fannullone.us wrote:
my $address_count = () = $str =~ /box|street|avenue|lane|apo/ig;
what does print $var = () = $str =~ /regex/; do?
particularly the '= () ='?
According to Effective Perl Programming (2nd Ed.), Item 9 (Know the
difference between lists and arrays)...
(I couldn't find the text online, so my apologies for poorly
paraphrasing the book)
Since the assignment operator is right associative, the '() = ...'
happens first, which forces the assignment operator to act in list
context on the regex match on the right. Then the '$var =' to the left
is the assignment operator in scalar context, which returns the number
of elements from the list on the right.
This code can be used to count the number of matches from your regex, if
you don't care to do anything with the actual matches.
my $count =()= m/(.)/g;
Apparently this is called the goatse operator. no kidding; that's
what the book says.
per the question, maybe something like this:
my @match = [ qr/one/i, qr/two/i, qr/etc/i ];
my @words = split /[^\s]+/, $fields;
my $count = 0;
foreach my $word (@words) {
$count++ if( $word ~~ @match );
}
print cool\n if $count= 2;
How does this code work? For one thing, you have @match = [ ]; which is
assigning an array reference to an array? Maybe I'm not understanding
something... I tweaked your code to the following, since I had problems
compiling it as you wrote it:
my $match = [ qr/one/i, qr/two/i, qr/etc/i ];
my @words = split /\s/, $fields;
my $count = 0;
foreach my $word (@words) {
foreach (@$match) {
if ( $word =~ $_ ) {
$count++;
last;
}
}
}
print cool\n if $count = 2;
It's certainly not as short as your code. Is this basically the same
logic you were going for?
Here's a slightly different take I thought a 'map' or 'grep' might
be a cleaner way to go.
my @mail_types = qw( avenue road box lane );
my @words = split /\s/, $fields;
my $count = grep {
my $found;
foreach my $street ( @mail_types ) {
if ( /\b$street\b/i ) {
$found++;
last;
}
}
$found;
} @words;
print qq(found $count address types\n) if ( $count 1);
I think I was wrong; this is even longer, and too convoluted I'm
sure there's a better way...
Brian
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Re: How to test for 2 words from a list in a form field?
Brian F. Yulga wrote:
my @mail_types = qw( avenue road box lane );
my @words = split /\s/, $fields;
my $count = grep {
my $found;
foreach my $street ( @mail_types ) {
if ( /\b$street\b/i ) {
$found++;
last;
}
}
$found;
} @words;
print qq(found $count address types\n) if ( $count 1);
I think I was wrong; this is even longer, and too convoluted I'm
sure there's a better way...
Of course, two minutes after I send to the list, I get a much better
idea. My apologies for spamming all of you How about this:
my @mail_types = qw( street road box lane );
my $regex;
$regex .= q(\b) . $_ . q(\b|) foreach ( @mail_types );
$regex = substr $regex, 0, -1;
my $count = grep /$regex/i, @words;
print qq(found $count\n) if ( $count 1);
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Re: Filling in an online form.
Dennis Wicks wrote: Greetings; I want to setup a form on a web page that a visitor can fill in then send it back to me by email so I can browse it online and print it out locally in the correct format. I have the way to define the input form figured out, but the transmission and browsing and printing the form are giving me trouble, to say the least! My public web server (Apache) is not local. I have a local Apache2 web server that I use for testing. Can anybody point me to a tutorial or example of how to do this? (Using perl, of course!) Many TIA! Dennis I'm pretty new to Perl, but I'll try to tackle this one with what I know so far First of all, I'm not sure about what you mean by browse it online; do you want to store the content in a database? From my perspective your question seems vague. You'll have to define that more precisely... For the first half of your problem that I think I understand, I'll assume you need information on using CGI coupled with sending e-mail. I recently learned some of the basics of using Perl with the web through Chapter 14 - Introduction to CGI, of Beginning Perl, (3rd Ed.) by James Lee. It's not complete (for example, lacks security considerations), but the chapter reads like a tutorial and I found it easy to follow along and build the example script at the end of the chapter (webchess.pl). The book also refers the reader to Official Guide to Programming with CGI.pm by Lincoln Stein (the module's author). For official PerlDoc online documentation with an example, check out: http://perldoc.perl.org/CGI.html#A-COMPLETE-EXAMPLE-OF-A-SIMPLE-FORM-BASED-SCRIPT Working with the example above, the do_work() subroutine processes the form parameters. You should be able to apply the same concept to your problem, and have do_work() grab the posted data ( via the keys in the param() method ) and output to an e-mail, using the Mail::Mailer module: http://perldoc.perl.org/perlfaq9.html#How-do-I-send-mail? http://search.cpan.org/~markov/MailTools-2.07/lib/Mail/Mailer.pod Hope that gets you a start. Brian -- To unsubscribe, e-mail: beginners-unsubscr...@perl.org For additional commands, e-mail: beginners-h...@perl.org http://learn.perl.org/
Re: Using regex special characters from a string
Uri Guttman wrote:
BL == Ben Lavery ben.lav...@gmail.com writes:
BL #Here, using a hash looks much cleaner than
iterating through an array
hashes are almost always better for token lookups than scanning
arrays. don't doubt yourself in this area.
Jim Gibson wrote:
On 3/8/11 Tue Mar 8, 2011 2:51 PM, Ben Lavery ben.lav...@gmail.com
scribbled:
I'm wondering if I need to convert my hash of valid words into an
array, then
iterate through each entry with something like:
if($word_list[i] =~ m/$temp_word/){
push(@all_combinations, $temp_word);
}
You can use the built-in grep function to compare each of the words
in your
word list to your specified pattern, used as a regular expression, and
return all that match. In that case, the period is fine, as it will match
any character:
my @matches = grep( /^$temp_word$/i, @word_list );
push( @all_combinations, @matches );
Uri and Jim have hit upon one of my major stumbling blocks with learning
Perl. There seems to be a difference of opinion on the proper times to
use hashes vs. arrays/lists...and how best to use them. For those that
have heard of this book, I'm currently digesting this piece of information:
Effective Perl Programming, 2nd Ed., Item 9: Know the difference
between lists and arrays.
I have this suspicion that it relates to how C/C++ programmers write C
programs in Perl, rather than Perl programs. For instance, someone in
the C mindset might be tempted to write the above 'grep' as (following
code is a bad idea, I know...):
foreach ( @word_list ) {
if ( /^$temp_word$/i ) {
push( @all_combinations, ( $_ ));
}
}
I understand that this is very inefficient in Perl, and (please correct
me if I'm wrong) that Perl is optimized to search and manipulate hashes
and lists as a whole, rather than executing code over each item
one-at-a-time. So, I get the idea that I should treat a list of items
as a LIST (as a whole), rather than the conventional thinking of
enumerating each item of a list into an array. Please tell me, gurus,
if I'm on the right track! ;-)
So, my question becomes, why is hash manipulation more efficient than
list manipulation?? Uri states that hashes are better for for token
lookups than scanning arrays. But each key in the hash has an unused
associated value (1) in this case, which increases the amount of data
stored in memory. Maybe that's inconsequential. But, if we grep a
list (as Jim suggests) instead of scan an array, shouldn't the list
manipulation be more efficient (or at least equivalently efficient) to a
hash lookup?
Thanks in advance for your sharing your thoughts...
Brian
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Re: Using regex special characters from a string
Jim Gibson wrote:
On 3/9/11 Wed Mar 9, 2011 9:22 AM, Brian F. Yulga
byu...@langly.dyndns.org scribbled:
foreach ( @word_list ) { if ( /^$temp_word$/i ) { push(
@all_combinations, ( $_ )); } }
That is pretty much what the grep function is doing. It has to
iterate over the entire array and evaluate its code block for each
element and form a list of the array elements that evaluate to true.
There is no way to eliminate the requirement to scan the entire
array.
Ah, my (poor) assumption was that 'grep' was more magical in its
internal mechanisms for searching. Since it still acts on each member
of the list, the rest of my argument is defunct.
I understand that this is very inefficient in Perl, and (please
correct me if I'm wrong)
You are wrong.
each item of a list into an array. Please tell me, gurus, if I'm
on the right track! ;-)
You are not.
Ouch. Well, I'm here to learn.
So, my question becomes, why is hash manipulation more efficient
than list manipulation??
Because to find an element in a hash does not require iterating over
the entire hash. Perl can find a (key,value) pair by evaluating the
hash of the key, then going right to where the value is stored. It is
almost like finding the element of an array knowing the index value,
rather than having to scan the entire array looking for a certain
value.
so... key converts to hash in one step, then jumps directly to that
position (if hash for that key is defined). And if you're only looking
up the existence of the key in the table, no additional resources are
used to read the value from memory. I can see how that's way more
efficient than scanning all array indexes and reading each value.
Especially for large lists. But, there must be a slight trade-off...
the processing required to initialize the hash table with it's keys and
values is probably more intensive than defining an array with its
respective values? Unless, internally, Perl stores arrays as hashes,
with the indexes as the keys.
But, if we grep a list (as Jim suggests) instead of scan an
array, shouldn't the list manipulation be more efficient (or at
least equivalently efficient) to a hash lookup?
No, grep has to scan the entire array, one element at a time. Using
grep instead of a for loop might be more efficient, because of the
internal mechanisms of Perl, but the time required is still
proportional to the number of elements in the array. There is no way
around that.
Not much can be done with the list as a whole. You can take a
reference to it and find out how many elements, but anything else
productive will almost surely involve scanning the array and
accessing the elements, one at a time.
Thanks much for the explanation...now I understand Uri's comments! and
I can appreciate that hashes are more powerful and flexible than I
originally gave them credit for (I always thought of hashes as just
fancy arrays with strings instead of numbers for indexes).
It also makes me wonder if the time spent learning linked lists in C
programming class would have been better spent learning useful
programming theory with Perl...
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Re: Using regex special characters from a string
Ben Lavery wrote: there must be a slight trade-off... the processing required to initialize the hash table with it's keys and values is probably more intensive than defining an array with its respective values? Unless, internally, Perl stores arrays as hashes, with the indexes as the keys. I would have thought there would be more of a hit for initialising hashes over arrays, but the gains in efficiency later would outweigh that hit I'd have though? Initially I was going to ask: Comparing hashes to arrays, at what scale is the extra time required for hash initialization offset by the decreased time in searching? 10 items? 100? 1000? But, I realized that the problem isn't that simple, because it depends on the operations you perform on the hash after you initialize it. I get the impression (from reading this mailing list and other sources) that in most cases, the performance hit of initialization is relatively minor, compared to the performance gains later on. In other words, if there is a relatively direct (or natural) way to put your data into a hash instead of an array, it's worth it. And for some situations, if the values are unique, to define a mirrored hash (value = key) so that it's faster to search for values as key lookups instead. -- To unsubscribe, e-mail: beginners-unsubscr...@perl.org For additional commands, e-mail: beginners-h...@perl.org http://learn.perl.org/
Re: Using regex special characters from a string
Thanks for the reading suggestions! Brian Fraser wrote: On Wed, Mar 9, 2011 at 2:22 PM, Brian F. Yulga byu...@langly.dyndns.org mailto:byu...@langly.dyndns.org wrote: Uri and Jim have hit upon one of my major stumbling blocks with learning Perl. There seems to be a difference of opinion on the proper times to use hashes vs. arrays/lists...and how best to use them. http://perldoc.perl.org/perlfaq4.html#How-can-I-remove-duplicate-elements-from-a-list-or-array%3f Use a hash. When you think the words unique or duplicated, think hash keys. Very informative! Also in the following section, How can I tell whether a certain element is contained in a list or array? Hearing the word in is an indication that you probably should have used a hash, not a list or array, to store your data. Also the Hashes chapter of Learning Perl has a section called something like Why use Hashes, which seems fitting enough. counting words is the fourth example :-) That section mentions that hashes are useful for related data, or database-like data, but wasn't entirely convincing for me because it didn't mention performance. Same with the Hashes part of Modern Perl ( http://www.onyxneon.com/books/modern_perl/index.html ), in the The Perl Language chapter. For those that have heard of this book, I'm currently digesting this piece of information: Effective Perl Programming, 2nd Ed., Item 9: Know the difference between lists and arrays. See Item 13: Use arrays or hashes to group data. Also, www.effectiveperlprogramming.com http://www.effectiveperlprogramming.com. A useful read, but similar to Learning Perl, it doesn't mention the performance aspect. In this situation, I think the perlfaq provides the most convincing argument. I don't know if others had this problem when learning Perl, but the TMTOWTDI philosophy sometimes makes it difficult for me to discover better ways of doing things after I find one clunky way that works (hence my recent purchase of Effective Perl Programming, with the intention of acquiring Perl Best Practices in the future). -- To unsubscribe, e-mail: beginners-unsubscr...@perl.org For additional commands, e-mail: beginners-h...@perl.org http://learn.perl.org/
Re: Auto correction of typos
shawn wilson wrote: On Mar 7, 2011 11:37 AM, Brandon McCaig bamcc...@gmail.com wrote: On Mon, Mar 7, 2011 at 5:22 AM, Ramprasad Prasad ramprasad...@gmail.com wrote: 1) Create a hash of aliases for frequently used domains and their typos For eg gmaill.com = gmail.com hotmal.com = hotmail.com etc when I get the email id with these typos , I will prompt the user for correction , If accepted then thats fine It's difficult to predict every possible typo that a user is going to make. They could have their hands off-by-one and type something completely different. Perhaps you could instead just store a list of common mail domains and warn the user to double-check if their E-mail address doesn't match any of them. Yeah. However if he's going to go that far, he might as well just check for an mx record for the domain. Also, that hash is going to get unwieldy pretty quick. If there's no db already, might want to use sqlite. Heh, too bad he didn't like my capcha of the email address for confirmation. I kinda think that was one of my better ideas. :) I agree -- I think you would spend considerable time attempting to predict typos, when a simpler validation model could be written and implemented relatively quickly. For instance, I would tackle this problem with some straightforward client-side JavaScript. Before passing the form results back to the server for processing (and further validation if desired), you could use the prompt() or confirm() methods of the Window object. With prompt(), you could require the user to enter the address a second time. With confirm(), you could force them to inspect the address before continuing on with submission. I'm not sure if web bots could work through this logic and still spam you... I'm not a big fan of my own suggestion, since encountering dialog boxes while browsing can be annoying to the user. But, I think most types of entry validation annoy users, even if it's for their own good. IMO, the Capcha idea is probably the best bang for the buck; requires only moderate coding (some are just copy-paste code snippets) and gives you a high level of human authentication. The downside is that the capcha phrases are sometimes ambiguous, and the user might have to try more than once to submit. A quick Google search revealed an article you may find useful, if you'd still like to tackle the problem with your original idea: http://www.infoq.com/articles/lucene-did-you-mean Granted, it's not a Perl solution, but it is the same programming logic you would need. Notice that it requires a suitable dictionary of reference words (e-mail domains for your case) so you would still have a lot of work to do... Good Luck! Brian -- To unsubscribe, e-mail: beginners-unsubscr...@perl.org For additional commands, e-mail: beginners-h...@perl.org http://learn.perl.org/
Re: multidimensional array check
Rob Coops wrote: So you should now be able to retrieve the whole result set as a reference to an array containing references to arrays. And I hope that my ramblings explained a bit how you can use that reference to get to the underlying values. If you combine all of that I think you'll be able to work out the way to get your program to work the way you want it to. FWIW, I found your ramblings quite helpful, since I am working to get more comfortable with variables, arrays, and references, on my way to learning objects. Coming from a basic understanding of C, the reference variable concept sounds a lot like pointers in C. But, my Learning Perl and Intermediate Perl books do not use that terminology. Am I on a correct path to understanding by making this analogy? Thanks, Brian -- To unsubscribe, e-mail: beginners-unsubscr...@perl.org For additional commands, e-mail: beginners-h...@perl.org http://learn.perl.org/
Re: multidimensional array check
Thanks for the link. That's exactly the explanation I was looking for... I progressed quickly through the first Oreilly book (Learning Perl) but slowed down considerably in the 2nd (Intermediate Perl). I found the chapter on Subroutine References (7) more difficult than earlier material (my brain nearly exploded when reading the section returning a subroutine from a subroutine) so I decided to stop and go back to basics until I achieve a better understanding. It didn't occur to me to open up the Advanced Perl Programming book (what I intended to read as my 3rd book)! Rob Coops wrote: You are very right a really nice explanation of this you can find in the Advanced Perl Programming book by Oreilly see the link below http://oreilly.com/catalog/advperl/excerpt/ch01.html If you already went trough the other two then this is definitely a good one to read as it goes that extra step and provides you with a good insight of the underlying logic. On Fri, Mar 4, 2011 at 7:30 PM, Brian F. Yulga byu...@langly.dyndns.org mailto:byu...@langly.dyndns.org wrote: Rob Coops wrote: So you should now be able to retrieve the whole result set as a reference to an array containing references to arrays. And I hope that my ramblings explained a bit how you can use that reference to get to the underlying values. If you combine all of that I think you'll be able to work out the way to get your program to work the way you want it to. FWIW, I found your ramblings quite helpful, since I am working to get more comfortable with variables, arrays, and references, on my way to learning objects. Coming from a basic understanding of C, the reference variable concept sounds a lot like pointers in C. But, my Learning Perl and Intermediate Perl books do not use that terminology. Am I on a correct path to understanding by making this analogy? Thanks, Brian -- To unsubscribe, e-mail: beginners-unsubscr...@perl.org For additional commands, e-mail: beginners-h...@perl.org http://learn.perl.org/
Re: multidimensional array check
Shawn H Corey wrote: On 11-03-04 02:30 PM, Brian F. Yulga wrote: my brain nearly exploded when reading the section returning a subroutine from a subroutine Just wait until you get to the part where you can treat an anonymous subroutine as an object. :D For details, see `perldoc -f bless`. bless REF This function tells the thingy referenced by REF that it is now an object in the CLASSNAME package. ... 'thingy' is a great technical term. ;-) When I learned rudimentary C/C++ in school, I was taught pointers and structs/classes initially as separate concepts, and later the two were connected. It's becoming apparent to me that learning Perl objects _requires_ a solid understanding of references first... -- To unsubscribe, e-mail: beginners-unsubscr...@perl.org For additional commands, e-mail: beginners-h...@perl.org http://learn.perl.org/
Re: Testing File Contents
On Wed, 2 Mar 2011, Matt wrote:
The easiest way in my opinion is to use the 'grep' function like this:
my $searchstring=whatever;
open CFG, '', $_file || die(could not open file: $_file!);
my @data=CFG;
close CFG;
if ( grep /$searchstring/i, @data ) {
print $searchstring found\n;
}
This sorta worked. Needed a minor change.
unless ( grep /$searchstring/i, @data ) {
print $searchstring not found\n;
Thanks.
My apologies if I'm beating a dead horse here, but I'm new to Perl and
thought of a slightly different approach:
my $searchrx = qr/whatever/; # or q/whatever/ if you don't need regexp
@ARGV or die qq/you didn't specify a filename\n/;
open FH, q//, shift @ARGV or die qq/file open error: $!/;
$_ = join q//, FH;
close FH;
if ( ! m/$searchrx/s ) {
print qq/pattern not found\n/;
# do something
}
I'm not sure which is more Perlish, but I hear TMTOWTDI is supposed to
be valued, too. I welcome any criticism.
Brian
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Re: Testing File Contents
Ken Slater wrote:
From: Brian F. Yulga [mailto:byu...@langly.dyndns.org]
On Wed, 2 Mar 2011, Matt wrote:
The easiest way in my opinion is to use the 'grep' function like
this:
my $searchstring=whatever; open CFG, '', $_file || die(could
not open file: $_file!); my @data=CFG; close CFG; if ( grep
/$searchstring/i, @data ) { print $searchstring found\n; }
This sorta worked. Needed a minor change.
unless ( grep /$searchstring/i, @data ) { print $searchstring
not found\n;
Thanks.
My apologies if I'm beating a dead horse here, but I'm new to Perl
and thought of a slightly different approach:
my $searchrx = qr/whatever/; # or q/whatever/ if you don't need
regexp
This is probably personal preference, but I prefer to provide a more
meaningful name rather than using @ARGV. Plus you have lost the
filename once you 'shifted' @ARGV in the open statement. May want to
use the file name in the open error statement or later.
I agree with you, saving the filename to a variable is probably a better
practice, in general. In this context it wasn't specified that it was
needed later, so I opted to just 'shift' it to use once.
Also, I would not use the '/' as your quote delimiter - that's too
recognizable as being used as the pattern match delimiter. Use actual
double quotes () unless there are double quotes in the string - also
less typing. Instead of '/' may want to use '{' and '}' if using qq
(see perldoc perlop, Quote and Quote-like Operators).
Good point. I started using generic quotes almost exclusively when I
discovered that they avoided some of the possible shell-interpolation
issues that arise when executing perl one-liners. I've probably taken
it too far. I can see that '/' is not a great idea. Besides '{' and
'}' as quote delimiters, do you think it's generally tolerated to use
'(', ')', '[', ']' ?
my $fileName = shift @ARGV or die You did not specify a
filename\n;
@ARGV or die qq/you didn't specify a filename\n/;
Use lexical variable for filehandle. Makes things easier - such as
passing to a function.
open my $FH,'', $fileName or die Error opening $fileName: $!\n;
open FH, q//, shift @ARGV or die qq/file open error: $!/;
Okay, I'll work on breaking that habit. My first lessons in Perl used
the open FH convention, and I just got used to it.
The join is unnecessary, set the input_record_separator ($/) to undef
or use a local copy of $/ (see perldoc perlvar). If this is
undefined, the entire file will be read into a variable.
Oh, I totally forgot about the input_record_separator ( $/ )...
That's WAY better (actually when I wrote the 'join', I was thinking that
I shouldn't need to do it that way!)
Thanks much for the suggestions,
Brian
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Re: Testing File Contents
Uri Guttman wrote:
BFY == Brian F Yulga byu...@langly.dyndns.org writes:
BFY My apologies if I'm beating a dead horse here, but I'm new to
Perl and BFY thought of a slightly different approach:
BFY my $searchrx = qr/whatever/; # or q/whatever/ if you don't need
regexp BFY @ARGV or die qq/you didn't specify a filename\n/; BFY
open FH, q//, shift @ARGV or die qq/file open error: $!/; BFY $_ =
join q//, FH;
that is very slow and clunky. perl could slurp the file for you if
you set $/ to undef. or better yet, use File::Slurp to do it
Yes, definitely better to set $/ to undef.
I'm still trying to get a handle on the libraries at my disposal --
There's so much in CPAN it's hard to know where to start. Is it
equivalently efficient to use IO::All or IO::Simple, or is File::Slurp
truly the best for this purpose?
I ask because I played with IO:All to read files, enjoyed the simple,
intuitive syntax my $filecontents io('filename'); , but (perhaps
naively) assumed the native open my $fh to be faster since it doesn't
require a use to load a library.
BFY close FH; BFY if ( ! m/$searchrx/s ) {
why are you using m//? the m isn't needed if you use // for
delimiters
Yeah, I know, I don't need it... being verbose (sometimes) keeps a
newbie like me from making silly mistakes :-)
My initial experimentation with Perl has been mostly in a line-by-line
mind-set because I have a tendency to write scripts that are used like:
some-unix-command | perl -wne 'do some processing' myresults.txt
I'm trying to expand my horizons, thanks for help,
Brian
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