Sed

Check the APO unix pages for more.

Tricks

sed 's/\r//' filename > newfilename

dos2unix substitute, remove all dos line endings.

sed -i 'commands' filename

Edit the file directly (inplace) by default the result is sent to standard output

Basics

sed 's/<old_string>/<new_string>/g' <file>

Substitute, no whitespace is allowed after the command (s), the first character following s is the fieldseperator./g substitutes all matching patterns in a line.

sed 's/pattern(with)sub(patterns)/\1 newpartofstring \2/' <file>

\1 and \2 refer to the subpatterns between brackets ().

sed '/<pattern>/d'

Delete matching line. !d negates the match => delete all lines not matching.