Editing M4 (computer language) (section)

{{lowercase|m4}}
{{Short description|General-purpose macro processor}}
{{Infobox programming language
| name                   = m4
| logo                   = 
| paradigm               = [[macro (computer science)|macro]]
| year                   = {{Start date and age|1977}}
| designer               = [[Brian Kernighan]], [[Dennis Ritchie]]
| developer              = 
| latest_release_version = 
| latest_release_date    = 
| implementations        = [[GNU m4]]
| typing                 = 
| influenced_by          = 
| operating_system       = 
| license                = 
| website                = 
}}
'''m4''' is a [[general-purpose macro processor]] included in most [[Unix-like]] operating systems, and is a component of the [[POSIX]] standard.

The language was designed by [[Brian Kernighan]] and [[Dennis Ritchie]] for the original versions of [[UNIX]]. It is an extension of an earlier macro processor, m3, written by Ritchie for an unknown AP-3 minicomputer.<ref name='KR1977'>Brian W. Kernighan and Dennis M. Ritchie. The m4 macro processor. Technical report, Bell Laboratories, Murray Hill, New Jersey, USA, 1977. [http://wolfram.schneider.org/bsd/7thEdManVol2/m4/m4.pdf pdf]</ref>

The macro [[preprocessor]] operates as a text-replacement tool. It is employed to re-use text templates, typically in [[computer programming]] applications, but also in text editing and text-processing applications. Most users require m4 as a dependency of GNU [[autoconf]] and [[GNU Bison]].