perl regex with variables

Question

set release=//packages/thirdparty/release/main.txt

perl -pe"s!(//packages/thirdparty/release/main.txt *)#\d+!$1#15!;" testlog.txt

How can I use %release% (environment variable release) instead of //packages/thirdparty/release/main.txt?

I'm getting syntax error from

 perl -pe"s!(%release%! *)#\d+!$1#15!;" testlog.txt

Avinash, thank you for your help but answer provided by "Borodin" worked. — Mihir
– Mihir, Commented Mar 17, 2015 at 14:36

Borodin · Accepted Answer · 2015-03-17 14:31:13Z

3

You can use the %ENV hash to access environment variables, like this

perl -pe"s/(\Q$ENV{RELEASE}\E *)#\d+/$1#15/" testlog.txt

You can also use a positive look-behind to avoid having to replace the initial string

perl -pe"s/(?<=\Q$ENV{RELEASE}\E *)#\d+/#15/" testlog.txt

or \K if you are running version 14 or later of Perl 5

perl -pe"s/\Q$ENV{RELEASE}\E *\K#\d+/#15/" testlog.txt

answered Mar 17, 2015 at 14:31

Borodin

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