CODEWITHSUNDEEP
regexperl
Jasmine Lognnes
Jasmine Lognnes

Reputation: 7087

\Q is ignored it seams

Can someone tell me why my script below search/replace when I am using \Q$btype when it works when I hard code with center instead?

The script is suppose to insert $$ after \end{center}.

#!/usr/bin/perl

my $line = '\end{tabular}
\end{center}
end:text
';

my $btype = "center";
$line =~ s/\\end\{\Q$btype\}/\\end\{\Q$btype\}\$\$/g;
print "$line\n";

Upvotes: 0

Views: 85

Answers (1)

Toto
Toto

Reputation: 91385

You need to stop the escaping:

$line =~ s/\\end\{\Q$btype\E\}/\\end\{$btype\}\$\$/g;
#                  here __^^

it could be reduce to:

$line =~ s/\\end\{\Q$btype\E\}\K/\$\$/g;    # 5.10+

or

$line =~ s/(\\end\{\Q$btype\E\})/$1\$\$/g;

or

$line =~ s/\\end\{\Q$btype\E\}/$&\$\$/g;

From ThisSuitIsBlackNot's comment:
Don't use it with perl before v5.20 because of performance issue.

or

$line =~ s/(?<=\\end\{\Q$btype\E\})/\$\$/g;

Upvotes: 6

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