sed cheat sheet, feed command line by line to other command

S-command - Extract part of string

sed -n -r "s/(<string to search for>)/\\1/p"


-n = Do not print, without this the command will output everything but replace the search string with the replacement.
-r = Use extended regular expressions
p = Print what is matched
\1 = Output string between first set of parentheses ( ... ).

[[:space:]] is used instead of \s for spaces.

Feed output of one command line by line to another

This feeds the output of a command to echo:

command| while IFS= read -r line; do echo $line; done;

-r = Do not treat and remove backslashes
IFS=  = Do not truncate beginning of lines

Source: https://unix.stackexchange.com/questions/18886/why-is-while-ifs-read-used-so-often-instead-of-ifs-while-read/18936#18936