Perl One-liner

collection of one-liners.

# run contents of "my_file" as a program
perl my_file

# run debugger "stand-alone"
perl -d -e 42

# run program, but with warnings
perl -w my_file

# run program under debugger
perl -d my_file

# just check syntax, with warnings
perl -wc my_file

# useful at end of "find foo -print"
perl -nle unlink

# simplest one-liner program
perl -e 'print "hello world!\n"'

# add first and penultimate columns
perl -lane 'print $F[0] + $F[-2]'

# just lines 15 to 17
perl -ne 'print if 15 .. 17' *.pod

# print lines beween START and END in foo.txt to STDOUT
perl -ne 'print if /^START$/ .. /^END$/' foo.txt

# change all words "foo"s to "bar"s in every .c file and keep backups
perl -p -i.bak -e 's/\bfoo\b/bar/g' *.c

# substitute "xyz.math" to "abc.math" in every .html file and keep backups
perl -p -i.bak -e 's/xyz\.math/abc\.math/g' *.html

# insert department name after each title and keep backup
perl -p -i.bak -e 's#