The Basics 1sed -e '…' -e '…' # Several execution 2sed -i # Replace in place 3sed -r # Play with REGEX 4 5# The most usefull 6sed -e '/^[ ]*#/d' -e '/^$/d' <fich.> # openfile without empty or commented lines 7sed 's/ -/\n -/g' # replace all "-" with new lines 8sed 's/my_match.*/ /g' # remove from the match till end of line 9sed -i '4048d;3375d' ~/.ssh/known_hosts # delete lines Number 10 11# Buffer 12s/.*@(.*)/$1/; # keep what is after @ put it in buffer ( ) and reuse it with $1. 13sed -e '/^;/! s/.*-reserv.*/; Reserved: &/' file.txt # resuse search with & 14 15# Search a line 16sed -e '/192.168.130/ s/^/#/g' -i /etc/hosts # Comment a line 17sed -re 's/^;(r|R)eserved:/; Reserved:/g' file.txt # Search several string 18 19# Insert - add two lines below a match pattern 20sed -i '/.*\"description\".*/s/$/ \n \"after\" : \"network.target\"\,\n \"requires\" : \"network.target\"\,/g' my_File 21 22# Append 23sed '/WORD/ a Add this line after every line with WORD' 24 25# if no occurence, then add it after "use_authtok" 26sed -e '/remember=10/!s/use_authtok/& remember=10/' -i /etc/pam.d/system-auth-permanent