How to replace text in single or multiple files

sed commands change from distribution to distribution. The proposed method should be working for each distribution.

for i in *.file; do sed -i _modified 's/foo/bar/g' "$i"; mv "$i"_modified "$i"; done

If you want add filename into file, you could join another sed command. Our files have code_BLABLA.foo format:

for i in *.foo; do m="$( echo $i | sed 's/_[A-Z_]*.foo//g' )"; sed -i _ 's/#/code='$m'/g' "$i"; done

If you need add also “-” into code because it has ABC12345 format and you want ABC-12345 format:

for i in *.foo; do j="$( echo $i | sed 's/_[A-Z_]*.foo//g' )"; k="$( echo $j | sed 's/\([A-Z]*\)/\1-/' )"; sed -i _ 's/#/code='$k'/g' "$i"; done