Unix Filter IO Scheme

A filter is a command that accepts input from stdin, transforms it in some way and outputs the transformed contents into stdout.

• Filters are very easy to compose into UNIX pipelines.
• Extremely handy when editing text in a text editor that allows selecting text, running it through a filter and replacing the selected text with the output. (vi and vim, even emacs, etc)

Filters are of two types:

• Line filters - program transforms the input line by line
• File filters - program transforms the whole input received via stdin at once

Related:

• 20220112092321 CLI IO Schemes/Methods
• 20220112095121 Adding filter capabilities to any Bash function

Reference:

• What is a UNIX/Linux Filter - by rwxrob: https://github.com/rwxrob/zet/blob/e2ab6dbfdc73d54d3aef1634fa659d29d609b1c1/20210809223847/README.md

Tags:

#literature-note #unix #cli