tldr/pages/linux/sed.md

sed

GNU stream editor for filtering and transforming text. See also: awk, ed. More information: https://www.gnu.org/software/sed/manual/sed.html.

• Replace apple with mango on all lines using basic regex, print to stdout:

{{command}} | sed 's/apple/mango/g'

• Replace apple with APPLE on all lines using extended regex, print to stdout:

{{command}} | sed {{[-E|--regexp-extended]}} 's/(apple)/\U\1/g'

• Use basic regex to replace apple with mango and orange with lime in-place in a file (overwriting original file):

sed {{[-i|--in-place]}} -e 's/apple/mango/g' -e 's/orange/lime/g' {{path/to/file}}

• Execute a specific sed script file and print the result to stdout:

{{command}} | sed {{[-f|--file]}} {{path/to/script.sed}}

• [p]rint only the first line to stdout:

{{command}} | sed {{[-n|--quiet]}} '1p'

• [d]elete lines 1 to 5 of a file and back up the original file with a .orig extension:

sed {{[-i|--in-place=]}}{{.orig}} '1,5d' {{path/to/file}}

• [i]nsert a new line at the beginning of a file, overwriting the original file in-place:

sed {{[-i|--in-place]}} '1i\your new line text\' {{path/to/file}}

• Delete blank lines (with or without spaces/tabs) from a file, overwriting the original file in-place:

sed {{[-i|--in-place]}} '/^[[:space:]]*$/d' {{path/to/file}}