4 ms·

The reasons outlined for not using Perl actually all apply to purl as well, except maybe "not just for one-liners". But perl allows one-liners to emulate grep

The reasons outlined for not using Perl actually all apply to purl as well, except maybe "not just for one-liners". But perl allows one-liners to emulate grep (filter and exclude) and sed (replace): perl -p -e 's/FROM/HELLO/' # replace perl -n -e 'print if /FROM/' # filter perl -n -e 'print if not /FROM/' # exclude

rml 3y ago
more examples (from https://softpanorama.org/Scripting/Perlorama/One-liners/tom_christiansen_one-liners.shtml https://softpanorama.org/Scripting/Perlorama/One-liners/tom_...) # add first and penultimate columns perl -lane 'print $F[0] + $F[-2]' # print just lines 15 to 17 perl -ne 'print if 15 .. 17' *.pod # in-place edit of *.c files changing all foo to bar perl -p -i.bak -e 's/\bfoo\b/bar/g' *.c # command-line that prints the first 50 lines (cheaply) perl -pe 'exit if $. > 50' f1 f2 f3 ... # delete first 10 lines perl -i.old -ne 'print unless 1 .. 10' foo.txt # change all the isolated oldvar occurrences to newvar perl -i.old -pe 's{\boldvar\b}{newvar}g' *.[chy] # command-line that reverses the whole file by lines perl -e 'print reverse <>' file1 file2 file3 .... # find palindromes perl -lne 'print if $_ eq reverse' /usr/dict/words # command-line that reverse all the bytes in a file perl -0777e 'print scalar reverse <>' f1 f2 f3 ... # command-line that reverses the whole file by paragraphs perl -00 -e 'print reverse <>' file1 file2 file3 .... # increment all numbers found in these files perl i.tiny -pe 's/(\d+)/ 1 + $1 /ge' file1 file2 .... # command-line that shows each line with its characters backwards perl -nle 'print scalar reverse $_' file1 file2 file3 .... # delete all but lines between START and END perl -i.old -ne 'print unless /^START$/ .. /^END$/' foo.txt # binary edit (careful!) perl -i.bak -pe 's/Mozilla/Slopoke/g' /usr/local/bin/netscape # look for dup words perl -0777 -ne 'print "$.: doubled $_\n" while /\b(\w+)\b\s+\b\1\b/gi' # command-line that prints the last 50 lines (expensively) perl -e 'lines = <>; print @@lines[ $#lines .. $#lines-50' f1 f2 f3 ...

rml 3y ago

more examples (from https://softpanorama.org/Scripting/Perlorama/One-liners/tom_christiansen_one-liners.shtml https://softpanorama.org/Scripting/Perlorama/One-liners/tom_...) # add first and penultimate columns perl -lane 'print $F[0] + $F[-2]' # print just lines 15 to 17 perl -ne 'print if 15 .. 17' *.pod # in-place edit of *.c files changing all foo to bar perl -p -i.bak -e 's/\bfoo\b/bar/g' *.c # command-line that prints the first 50 lines (cheaply) perl -pe 'exit if $. > 50' f1 f2 f3 ... # delete first 10 lines perl -i.old -ne 'print unless 1 .. 10' foo.txt # change all the isolated oldvar occurrences to newvar perl -i.old -pe 's{\boldvar\b}{newvar}g' *.[chy] # command-line that reverses the whole file by lines perl -e 'print reverse <>' file1 file2 file3 .... # find palindromes perl -lne 'print if $_ eq reverse' /usr/dict/words # command-line that reverse all the bytes in a file perl -0777e 'print scalar reverse <>' f1 f2 f3 ... # command-line that reverses the whole file by paragraphs perl -00 -e 'print reverse <>' file1 file2 file3 .... # increment all numbers found in these files perl i.tiny -pe 's/(\d+)/ 1 + $1 /ge' file1 file2 .... # command-line that shows each line with its characters backwards perl -nle 'print scalar reverse $_' file1 file2 file3 .... # delete all but lines between START and END perl -i.old -ne 'print unless /^START$/ .. /^END$/' foo.txt # binary edit (careful!) perl -i.bak -pe 's/Mozilla/Slopoke/g' /usr/local/bin/netscape # look for dup words perl -0777 -ne 'print "$.: doubled $_\n" while /\b(\w+)\b\s+\b\1\b/gi' # command-line that prints the last 50 lines (expensively) perl -e 'lines = <>; print @@lines[ $#lines .. $#lines-50' f1 f2 f3 ...