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}}

• Edit all file lines [i]n-place with a specific replacement [e]xpression and save a file with a new extension:

perl -p -i'.{{extension}}' -e 's/{{regular_expression}}/{{replacement}}/g' {{path/to/file}}

• Run a multi-line replacement [e]xpression on a file, and save the result in a specific file:

perl -p -e 's/{{foo\nbar}}/{{foobar}}/g' {{path/to/input_file}} > {{path/to/output_file}}

• Run a regular [e]xpression on stdin, printing matching [l]ines:

cat {{path/to/file}} | perl -n -l -e 'print if /{{regular_expression}}/'

• Run a regular [e]xpression on stdin, printing only the first capture group for each matching [l]ine:

cat {{path/to/file}} | perl -n -l -e 'print $1 if /{{before}}({{regular_expression}}){{after}}/'