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}}`