sed

The article introduces GNU sed, a non-interactive command-line text editor commonly used to filter text through pattern matching or substitution. It provides examples of its use, such as deleting the fourth line of a file or replacing a string within a specified range of lines. The article also includes a table of contents with links to various resources related to sed, including the latest source, downloads, and mailing lists for support and bug reports. The Free Software Foundation (FSF), which supports the development of GNU sed, is a nonprofit organization dedicated to promoting computer user freedom. The article offers ways to get involved with the development of GNU sed, such as subscribing to the mailing list or reporting bugs. The article ends with information about the FSF and links to related projects and resources.