Multiple expressions

Apply multiple substitutions in one command

sed -e 's/foo/bar/g' -e 's/baz/qux/g' file.txt

More sed commands

Strip leading/trailing whitespace

sed 's/^[[:space:]]*//;s/[[:space:]]*$//' file.txt

Trim leading and trailing whitespace from each line
Address range substitution

sed '5,15s/DEBUG/INFO/g' app.log

Apply substitution only to lines 5 through 15
Extract value from key=value file

sed -n 's/^DB_HOST=//p' .env

Print the value of DB_HOST from a .env file
Substitute first match per line

sed 's/foo/bar/' file.txt

Replace the first occurrence of 'foo' with 'bar' per line
Substitute all matches (global)

sed 's/foo/bar/g' file.txt

Replace every occurrence per line with the /g flag