UNIX tools vs Perl

This article compares how simple tasks are done using UNIX tools and Perl one-liners.

sed

task	sed	perl
Replace 12 with twelve	sed 's/12/twelve/g'	perl -pe 's/12/twelve/g'
Replace the word sh with Bourne Shell	sed -e 's/ sh / Bourne Shell /g'	perl -pe 's/\bsh\b/Bourne Shell/g'
Remove lines 2 to 4 from stream	sed '2,4d'	perl -nle 'print if $.<2 || $.>4'

awk

task	awk	perl
Print second field (whitespace-separated)	awk '{print $2}'	perl -lane 'print $F[1]'
Count lines starting with X	awk '/^X/ {++x} END {print x}'	perl -nle '++$x if /^X/; print $x if eof'
Add numbers in second column and print sum	awk '{sum+=$2} END {print sum}'	perl -lane '$sum+=$F[1]; print $sum if eof'

tr

task	tr	perl
ROT13	tr 'A-Za-z' 'N-ZA-Mn-za-m'	perl -pe 'y/A-Za-z/N-ZA-Mn-za-m/'
Remove carriage return from DOS files	tr -d '\r'	perl -pe 'tr/\r//d'

grep

task	grep	perl
Print only lines containing 12	grep '12'	perl -nle 'print if /12/'
Print only lines not containing 12	grep -v '12'	perl -nle 'print if !/12/'

nl

task	nl	perl
Insert line numbers (lined up)	nl -ba	perl -nle 'printf "%6s %s\n", $., $_'