sponge(1)

sponge1

Soak up standard input and write to a file

Usage

sed {' ... ' file | grep ' ... ' | sponge [-a] file}

Overview

sponge reads standard input and writes it out to the specified file. Unlike a shell redirect, sponge soaks up all its input before writing the output file. This allows constructing pipelines that read from and write to the same file.

sponge preserves the permissions of the output file if it already exists.

When possible, sponge creates or updates the output file atomically by renaming a temp file into place. (This cannot be done if TMPDIR is not in the same filesystem.)

If the output file is a special file or symlink, the data will be written to it, non-atomically.

If no file is specified, sponge outputs to stdout.

Options

FC-aF[0]

Replace the file with a new file that contains the file's original content, with the standard input appended to it. This is done atomically when possible.

Releases

11 releases since Debian 4.0 (Etch); the text changed 7 times.

  1. 4.0
  2. 5.0
  3. 6.0
  4. 7
  5. 8
  6. 9–10
  7. 11–13
  8. Arch

-a until Debian 13 (Trixie).

Author

Colin Watson and Tollef Fog Heen

From moreutils 0.70-1 in Arch Linux 2026-11-01. Parsed by carta from the page's man source.