CODEWITHSUNDEEP
regexperl
Asuka
Asuka

Reputation: 21

perl $ anchor failed to match end of line

Example: my $pattern = "mkdir a &"

As you can see, my patterns are commands and I want to do a pattern match for "&+EOL" to distinguish whether this command runs on background or not.

I tried with /&$/, /&\$/ but failed.

What is wrong? What is your suggestion with this pattern match?

45: if ($command =~ /&$/) {

DB<2> p $command

mkdir a &

DB<3> s

54: print $_;print "\n";

Upvotes: 1

Views: 5997

Answers (2)

baddger964
baddger964

Reputation: 1237

Try using this : /&\n|&$/.

$ match the end of the string so if yours commands are all in the same string the pattern will not work.

\n match a newline.

Upvotes: 0

Borodin
Borodin

Reputation: 126762

Your pattern works fine

use strict;
use warnings 'all';
use feature 'say';

my $pattern = 'mkdir a &';

say $pattern =~ /&$/ ? 'match' : 'no match';

output

match

It is impossible to tell from your question, but it is likely that you have some whitespace at the end of the string you are trying to match. Perhaps you have a space or a linefeed there, or perhaps you are processing a file that has originated on Windows and you have removed only the LF, leaving a terminating CR.

You can fix this by adding optional whitespace at the end of your regex pattern, like this

say $pattern =~ /&\s*$/ ? 'match' : 'no match';

You can see exactly what your string contains using Data::Dumper, like this

use Data::Dumper;
$Data::Dumper::Useqq = 1;

print Dumper $pattern;

In this instance it produces $VAR1 = "mkdir a &";, and you will be able to see if there are any superfluous characters after the &.

Upvotes: 5

Related Questions