GNU sed – GNU Project – Free Software Foundation

GNU sed sed


flow editor) is a

non-interactive command-line text editor. # Example: delete the 4th line in a file $ sed ‘4d’ input.txt > output.txt # Example: Replace each occurrence of ‘hello’ with ‘world’ on the lines 10-20$ sed ‘10,20s/hello/world/’ input.txt > output.txt

sed is commonly used to filter text, i.e. it takes text input, performs some operation (or set of operations) on it, and generates the modified text. SED is typically used to extract part of a file by matching patterns or substituting multiple occurrences of a string within a file.

Get help

Read the manual

  • locally using info sed or view the latest manual online
  • . Search the archives for questions and answers above: questions, development, and general discussion: sed-devel mailing list

    • ;

    • Error reports: BUG-sed mailing list
    • . General sed resources are available in, including

    • : documentation

  • ,

    • FAQs, one-liners
    • , books,

    • and
    • sample scripts
  • . Send translation requests to the

  • Translation Project language team. Send
  • general questions or suggestions
  • to the mailing list on <>.

  • Report errors, including version and distribution variant, to the list in <>. Before submitting the error, check the FAQ and mailing list files (above). Often, these perceived errors are simply due to incorrect use of the program. For more information about reporting bugs, see Getting Help with GNU Software.


Stable source code versions are available on the main GNU download server (HTTPS, HTTP, FTP) and its mirrors. Please use a mirror if possible.

Most recent


The last source with revision history can be browsed using cgit or gitweb. Assuming you have git installed, you can retrieve the latest version with this command: git

clone git:// Please

note that we do not suggest using trial versions of sed for production use


Mailing lists

You do not need to be subscribed to post messages on any GNU mailing list. However, non-subscribers are moderated by humans, so be patient when waiting for your email to arrive.

You can subscribe to any GNU mailing list via the web as described below. Or you can send an empty email with a header line Subject: from simply “subscribe” to the relevant request list. For example, to subscribe to the main sed-devel list, you would send a full-bodied email to <> and a header line Subject: of just “subscribe”.

It has been necessary to moderate the sed mailing lists to avoid the avalanche of spam. Posts on lists are maintained for publication by the list moderator. Sometimes moderators are not available for short periods of time. Please be patient when posting. If you finally don’t see the message in the list file, then it wasn’t published.

Important announcements

about GNU sed and most other GNU programs are also made on the mailing list

The main discussion list for all things GNU sed is If you have questions, comments, or other general discussion about thirst, this is the mailing list for that discussion. If you don’t know where to start, then this is the place to start. You can browse and search for previous posts in the sed-devel file.


you think you have found an error in GNU sed, send as complete a bug report as possible to, and it will be automatically entered into the sed bug tracker. A very useful and often referenced guide on how to write bug reports and ask good questions is the document How to Ask Questions Smartly. You can browse previous posts and search the error file.

Platform testing Testing the

latest trial version (when available) is always appreciated. Thirst trial versions are usually advertised on the platform testers mailing list.

Enhancement requests

If you would like any new features to be included in future versions of sed, please submit a request to This is the general discussion list and a good place to start discussing a new feature. After considering it, you may be asked to log a request in the error tracker so that the problem is not lost. If you want to implement it yourself, note that non-trivial changes require the assignment of copyright to the FSF as detailed in the “Copyright Assignment” section of the GNU coreutils HACKING notes.

Mailing list tag

Please do not send messages encoded as HTML or encoded as base64 MIME or included as multiple formats. Please send messages as plain text. Please include a descriptive subject line. If all themes are bug, then it is impossible to differentiate them. Avoid sending large messages, such as log files, system call trace output, and other content that results in messages larger than 40 kB, to contactless mailing lists. It is best to send them directly to those who request that information after the initial contact.

Please remember that GNU sed development is a voluntary effort, and you can also contribute to its development. For information on how to contribute to the GNU Project, please read How to Help GNU.

GNU Maintainers are currently being maintained by Jim Meyering <>, and Assaf Gordon <>.