CODEWITHSUNDEEP
regexperl
divakar.scm
divakar.scm

Reputation: 1266

Perl reg expression to match end of string doesnt work

Not sure what is wrong in my perl script. unable to match the end of line using regular expression

[rmdev01@inches-rmdev01 SISPortal]$ forever logs
info:    Logs for running Forever processes
data:        script logfile
data:    [0] server /home/rmdev01/.forever/WusC.log
data:    [1] Server /home/rmdev01/.forever/2hai.log

script:

[rmdev01@inches-rmdev01 SISPortal]$ cat forever.pl
#! /usr/bin/perl

@logs=`forever logs`;

chomp(@logs);

foreach my $log (@logs)
{
        print "checking log at end of string $log\n";
        if ($log =~ /log$/)
        {
                print "$log\n";
        }
}

Output of script:

[rmdev01@inches-rmdev01 SISPortal]$ ./forever.pl
checking log at end of string info:    Logs for running Forever processes
checking log at end of string data:        script logfile
checking log at end of string data:    [0] server /home/rmdev01/.forever/WusC.log
checking log at end of string data:    [1] Server /home/rmdev01/.forever/2hai.log

Upvotes: 0

Views: 88

Answers (2)

ikegami
ikegami

Reputation: 385590

chomp only removes a line feed[1], while you apparently have other trailing whitespace (such as a carriage return).

s/\s+\z// removes all trailing whitespace, so it's using that is usually a better pratice than using chomp.

#!/usr/bin/perl

use strict;
use warnings qw( all );

for (`forever logs`) {
    s/\s+\n//;
    print if /log$/;   # Or /\blog$/ as Tim Pietzcker suggested.
}
  1. Technically, whatever the value of $/ is. But $/ start off containing a line feed.

Upvotes: 1

Tim Pietzcker
Tim Pietzcker

Reputation: 336108

It appears that there are some space/tab characters before the end of the string (chomp() only removes newlines, but no other whitespace characters).

Allow those trailing whitespace characters (and perhaps avoid matches like Blog by using a word boundary anchor):

if ($log =~ /\blog\s*$/)

Upvotes: 3

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