tldr/pages/common/perl.md

perl

The Perl 5 language interpreter. More information: https://www.perl.org.

• Parse and execute a Perl script:

perl {{script.pl}}

• Check syntax errors on a Perl script:

perl -c {{script.pl}}

• Parse and execute a Perl statement:

perl -e {{perl_statement}}

• Run a Perl script in debug mode, using perldebug:

perl -d {{script.pl}}

• Loo[p] over all lines of a file, editing them [i]n-place using a find/replace [e]xpression:

perl -p -i -e 's/{{find}}/{{replace}}/g' {{filename}}

• Run a find/replace expression on a file, saving the original file with a given extension:

perl -p -i'.old' -e 's/{{find}}/{{replace}}/g' {{filename}}

• Run a multi-line find/replace expression on a file, and save the result in another file:

perl -p0e 's/{{foo\nbar}}/{{foobar}}/g' {{input_file}} > {{output_file}}

• Run a regular expression on stdin, printing out the first capture group for each line:

cat {{path/to/input_file}} | perl -nle 'if (/.*({{foo}}).*/) {print "$1"; last;}'