RE: question about grep
Eric, > -Original Message- > From: Hawley, Eric [mailto:[EMAIL PROTECTED]] > actually I think I see what is wrong with the code. At > first I was reading the wrong variable which was producing > just the word "Status" and second after looking at the grep > function again it looks as though I will have to store the > file into a data structure and grep from that data structure > to get the desired results. There is, however, a really nice feature of the magical diamond "<>" that can help you. If you're writing one-shot code it can be a real time saver, but should not be used in production code as it's mostly silent when things go wrong. # pretend we got a whole load of lines from the command line @ARGV=<*.txt>; # grep the magical <> my @results = grep /^Status/, <>; As if by magic... Alistair --- Registered Office: Marks & Spencer p.l.c Michael House, Baker Street, London, W1U 8EP Registered No. 214436 in England and Wales. Telephone (020) 7935 4422 Facsimile (020) 7487 2670 www.marksandspencer.com Please note that electronic mail may be monitored. This e-mail is confidential. If you received it by mistake, please let us know and then delete it from your system; you should not copy, disclose, or distribute its contents to anyone nor act in reliance on this e-mail, as this is prohibited and may be unlawful. The registered office of Marks and Spencer Financial Services PLC, Marks and Spencer Unit Trust Management Limited, Marks and Spencer Life Assurance Limited and Marks and Spencer Savings and Investments Limited is Kings Meadow, Chester, CH99 9FB. ___ Perl-Win32-Users mailing list [EMAIL PROTECTED] To unsubscribe: http://listserv.ActiveState.com/mailman/mysubs
RE: question about grep
I'm gonna de-lurk for this one.
If you look at Peter's example, you will note that grep applies a block-or-something
to a list and returns a list.
You are applying it to the file name, not the contents. Perl grep doesn't read files.
If this wasn't the win32 perl list, I would just advise that you really want the
shell's grep
[ like $lines = `grep "^Status" $project_file` to get the Status line(s) from one file
]
Strictly within perl, you would need to open the file and snarf in its contents to
grep.
Maybe it would look like this (off the cuff, if errors, please point them out, to add
value for readers):
open (IFILE, "<$project_file" ) or die "useful message here:$!";
@lines = grep /^Status/, ;
close (IFILE);
# At this point, @lines has all the lines from $project_file that start with Status.
# If these files are HUGE, it might be better to roll your own match loop with while
() {...}
HTH,
Joe Dial
-Original Message-
From: Hawley, Eric [mailto:[EMAIL PROTECTED]]
Sent: Thursday, February 13, 2003 1:49 PM
To: 'Peter Guzis'; Perl-Win32 (E-mail)
Subject: RE: question about grep
I tried what you did suggested and it only pulled out the word Status, here
is the code below;
#location contains the path for the report to be stored
$report_location = $location;
$report_location =~ s/\//\\/;
$report_location = "$report_location" . "\\Reports";
unless( -e $report_location) ){
mkdir( $report_location ) or die "died creating Report Directory";
}
#open Report HTML file
open( FILE, "> $report_location\\$year_$month_$date_Report.htm" ) or die
"Dead creating Report";
#print intial html to report file
print FILE
"\n\n$year_$month_$date_report\n\n\n
";
#file paths include paths to the files, that Status should be greped from
#ex) C:\\Test.htm
foreach $project_file ( @file_paths ){
#grep Status line from $project_file
@status_line = grep /^Status/, $project_file;
}
print FILE "\n\n";
close(FILE);
Hope this can point to any failures.
Thanks
Eric
--
-Original Message-----
From: Peter Guzis [mailto:[EMAIL PROTECTED]]
Sent: Thursday, February 13, 2003 1:33 PM
To: Perl-Win32 (E-mail)
Subject: RE: question about grep
@matches = grep /^Status/, @data;
If this doesn't do it you might consider posting some sample data.
Peter Guzis
Web Administrator, Sr.
ENCAD, Inc.
- A Kodak Company
email: [EMAIL PROTECTED]
www.encad.com
-Original Message-
From: Hawley, Eric [mailto:[EMAIL PROTECTED]]
Sent: Thursday, February 13, 2003 10:23 AM
To: Perl-Win32 (E-mail)
Subject: question about grep
I got a question concerning grep. I would like to use it to pull out all
full lines of text, that starts with the word "Status", from a list of
files. I am not really too experienced with using Metacharacters and
Metasymbols and do not know how to go about doing this with grep. Can
someone help me out with this?
Thanks in advanced
Eric
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RE: question about grep
Eric
I'm in a pretty-code-mode at the moment, my apologies for the overkill.
> #location contains the path for the report to be stored
> $report_location = $location;
> $report_location =~ s/\//\\/;
To make this regex look a bit better you can use a different delimiter
rather than "/". Also you probably want to replace all "\" chars with "/" in
which case you need a 'g' at the end to make it a global replacement. Perl
has a much faster construct for replacing one character with another, i.e.
"tr".
$report_location =~ s!\/!\\!g; # better
$report_location =~ tr!\\!//!; # best;
See "perlop" for more info on "s" and "tr"
> $report_location = "$report_location" . "\\Reports";
A more explicit way of saying this using the ".=" construct. It saves you
having to double check that your left hand side is exactly the same as you
right hand side. It seems trivial here but is a godsend when debugging
something like $x[10101]{$y[101]]}= $x[10101]{$y[101]]} + $y[101];
$report_location.="\\Reports"
> unless( -e $report_location) ){
> mkdir( $report_location ) or die "died creating Report Directory";
> }
The -e operator tells you that a file exists. We have inherited from Unix
that a directory is a file. You might also want to check that
$report_location exists and is a directory. Id also suggest being a little
more informative to your users. Tell them what went wrong with the $!
variable. Also the idiom _this_ or _that_ can be IMHO elegantly extended
here
-d $report_location or
mkdir $report_location or
die "died creating Report Directory '$report_location': $!";
> #open Report HTML file
> open( FILE, ">
> $report_location\\$year_$month_$date_Report.htm" ) or die
> "Dead creating Report";
Note that perl will interpret this as "$year_"."$month_" etc. You probably
called your variables $year $month etc. So, to force perl to recognise where
the end of you variables are use {}'s. Make sure you put "use strict;" at
the top of your code and "my" all your variables otherwise perl will
silently evaluate them to "".
my $report_name=$report_location\\${year}_${month}_${date}_Report.htm";
open FILE, ">$report_name") or
die "Cannot write to $report_name : $!";
> #print intial html to report file
> print FILE
> "\n\n$year_$month_$date_report\n ead>\n\n
> ";
A more elegant construct for printing long strings is the "<
$year_$month_$date_report
Etc,
END_OF_HTML_HEADER
> foreach $project_file ( @file_paths ){
> #grep Status line from $project_file
> @status_line = grep /^Status/, $project_file;
> }
Note, $project_file will be a file name, not the contents of that file. You
need to open it and read :
foreach my $project_file ( @file_paths ){
open PROJFILE, $project_file or die "Cannot read $project_file :
$!";
my @status_lines = grep /^Status/, ; # Using the file in
an array context;
close PROJFILE;
DoStuff(@status_lines);
}
HTH
Alistair
---
Registered Office:
Marks & Spencer p.l.c
Michael House, Baker Street,
London, W1U 8EP
Registered No. 214436 in England and Wales.
Telephone (020) 7935 4422
Facsimile (020) 7487 2670
www.marksandspencer.com
Please note that electronic mail may be monitored.
This e-mail is confidential. If you received it by mistake, please let us know and
then delete it from your system; you should not copy, disclose, or distribute its
contents to anyone nor act in reliance on this e-mail, as this is prohibited and may
be unlawful.
The registered office of Marks and Spencer Financial Services PLC, Marks and Spencer
Unit Trust Management Limited, Marks and Spencer Life Assurance Limited and Marks and
Spencer Savings and Investments Limited is Kings Meadow, Chester, CH99 9FB.
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RE: question about grep
actually I think I see what is wrong with the code. At first I was reading the wrong variable which was producing just the word "Status" and second after looking at the grep function again it looks as though I will have to store the file into a data structure and grep from that data structure to get the desired results. Thanks for your input Eric -Original Message- From: Peter Guzis To: Perl-Win32 (E-mail) Sent: 2/13/03 1:32 PM Subject: RE: question about grep @matches = grep /^Status/, @data; If this doesn't do it you might consider posting some sample data. Peter Guzis Web Administrator, Sr. ENCAD, Inc. - A Kodak Company email: [EMAIL PROTECTED] www.encad.com -Original Message- From: Hawley, Eric [mailto:[EMAIL PROTECTED]] Sent: Thursday, February 13, 2003 10:23 AM To: Perl-Win32 (E-mail) Subject: question about grep I got a question concerning grep. I would like to use it to pull out all full lines of text, that starts with the word "Status", from a list of files. I am not really too experienced with using Metacharacters and Metasymbols and do not know how to go about doing this with grep. Can someone help me out with this? Thanks in advanced Eric ___ Perl-Win32-Users mailing list [EMAIL PROTECTED] To unsubscribe: http://listserv.ActiveState.com/mailman/mysubs ___ Perl-Win32-Users mailing list [EMAIL PROTECTED] To unsubscribe: http://listserv.ActiveState.com/mailman/mysubs ___ Perl-Win32-Users mailing list [EMAIL PROTECTED] To unsubscribe: http://listserv.ActiveState.com/mailman/mysubs
RE: question about grep
Do you want to pull out lines FROM files, or from a list of files?
e.g.: to print a list of lines beginning with 'my' from a directory of perl
scripts:
while (<*>){
open IN, "$_";
@matches = grep {/^my/} ;
close IN;
}
print @matches
HTH
From: "Hawley, Eric" <[EMAIL PROTECTED]>
To: "'Peter Guzis'" <[EMAIL PROTECTED]>, "Perl-Win32 \(E-mail\)"
<[EMAIL PROTECTED]>
Subject: RE: question about grep
Date: Thu, 13 Feb 2003 13:49:20 -0500
I tried what you did suggested and it only pulled out the word Status, here
is the code below;
#location contains the path for the report to be stored
$report_location = $location;
$report_location =~ s/\//\\/;
$report_location = "$report_location" . "\\Reports";
unless( -e $report_location) ){
mkdir( $report_location ) or die "died creating Report Directory";
}
#open Report HTML file
open( FILE, "> $report_location\\$year_$month_$date_Report.htm" ) or die
"Dead creating Report";
#print intial html to report file
print FILE
"\n\n$year_$month_$date_report\n\n\n
";
#file paths include paths to the files, that Status should be greped from
#ex) C:\\Test.htm
foreach $project_file ( @file_paths ){
#grep Status line from $project_file
@status_line = grep /^Status/, $project_file;
}
print FILE "\n\n";
close(FILE);
Hope this can point to any failures.
Thanks
Eric
------
-----Original Message-
From: Peter Guzis [mailto:[EMAIL PROTECTED]]
Sent: Thursday, February 13, 2003 1:33 PM
To: Perl-Win32 (E-mail)
Subject: RE: question about grep
@matches = grep /^Status/, @data;
If this doesn't do it you might consider posting some sample data.
Peter Guzis
Web Administrator, Sr.
ENCAD, Inc.
- A Kodak Company
email: [EMAIL PROTECTED]
www.encad.com
-Original Message-
From: Hawley, Eric [mailto:[EMAIL PROTECTED]]
Sent: Thursday, February 13, 2003 10:23 AM
To: Perl-Win32 (E-mail)
Subject: question about grep
I got a question concerning grep. I would like to use it to pull out all
full lines of text, that starts with the word "Status", from a list of
files. I am not really too experienced with using Metacharacters and
Metasymbols and do not know how to go about doing this with grep. Can
someone help me out with this?
Thanks in advanced
Eric
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RE: question about grep
I tried what you did suggested and it only pulled out the word Status, here
is the code below;
#location contains the path for the report to be stored
$report_location = $location;
$report_location =~ s/\//\\/;
$report_location = "$report_location" . "\\Reports";
unless( -e $report_location) ){
mkdir( $report_location ) or die "died creating Report Directory";
}
#open Report HTML file
open( FILE, "> $report_location\\$year_$month_$date_Report.htm" ) or die
"Dead creating Report";
#print intial html to report file
print FILE
"\n\n$year_$month_$date_report\n\n\n
";
#file paths include paths to the files, that Status should be greped from
#ex) C:\\Test.htm
foreach $project_file ( @file_paths ){
#grep Status line from $project_file
@status_line = grep /^Status/, $project_file;
}
print FILE "\n\n";
close(FILE);
Hope this can point to any failures.
Thanks
Eric
--
-Original Message-
From: Peter Guzis [mailto:[EMAIL PROTECTED]]
Sent: Thursday, February 13, 2003 1:33 PM
To: Perl-Win32 (E-mail)
Subject: RE: question about grep
@matches = grep /^Status/, @data;
If this doesn't do it you might consider posting some sample data.
Peter Guzis
Web Administrator, Sr.
ENCAD, Inc.
- A Kodak Company
email: [EMAIL PROTECTED]
www.encad.com
-Original Message-
From: Hawley, Eric [mailto:[EMAIL PROTECTED]]
Sent: Thursday, February 13, 2003 10:23 AM
To: Perl-Win32 (E-mail)
Subject: question about grep
I got a question concerning grep. I would like to use it to pull out all
full lines of text, that starts with the word "Status", from a list of
files. I am not really too experienced with using Metacharacters and
Metasymbols and do not know how to go about doing this with grep. Can
someone help me out with this?
Thanks in advanced
Eric
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RE: question about grep
@matches = grep /^Status/, @data; If this doesn't do it you might consider posting some sample data. Peter Guzis Web Administrator, Sr. ENCAD, Inc. - A Kodak Company email: [EMAIL PROTECTED] www.encad.com -Original Message- From: Hawley, Eric [mailto:[EMAIL PROTECTED]] Sent: Thursday, February 13, 2003 10:23 AM To: Perl-Win32 (E-mail) Subject: question about grep I got a question concerning grep. I would like to use it to pull out all full lines of text, that starts with the word "Status", from a list of files. I am not really too experienced with using Metacharacters and Metasymbols and do not know how to go about doing this with grep. Can someone help me out with this? Thanks in advanced Eric ___ Perl-Win32-Users mailing list [EMAIL PROTECTED] To unsubscribe: http://listserv.ActiveState.com/mailman/mysubs ___ Perl-Win32-Users mailing list [EMAIL PROTECTED] To unsubscribe: http://listserv.ActiveState.com/mailman/mysubs
