Perl: Command-line regex

A few command-line tricks for Perl:

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• **Filter based on regex (like grep -E) ** cat file.txt | perl -n -e ‘print if /regex.*matched/’

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• Replace based on regex cat file.txt | perl -n -e ‘s/regex.*matched/replacement/gi’

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• **Replace based on regex inside file (will change file) ** perl -pi -e ‘s/regex.*matched/replacement/gi’ *.txt

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• **Replace based on regex inside file (will change file) and make a backup of original file with .bak extension. ** perl -pi.bak -e ‘s/regex.*matched/replacement/gi’ *.txt