Editing Make (software) (section)

===Pattern rules ===

Suffix rules cannot have any prerequisites of their own.<ref>{{cite web|url=https://www.gnu.org/software/make/manual/html_node/Suffix-Rules.html#Suffix-Rules|title=GNU make manual: suffix rules|publisher=Free Software Foundation|access-date=2014-05-24|archive-date=2014-05-22|archive-url=https://web.archive.org/web/20140522130224/http://www.gnu.org/software/make/manual/html_node/Suffix-Rules.html#Suffix-Rules|url-status=live}}</ref> If they have any, they are treated as normal files with unusual names, not as suffix rules. GNU Make supports suffix rules for compatibility with old makefiles but otherwise encourages usage of ''pattern rules''.<ref>{{cite web|url=https://www.gnu.org/software/make/manual/html_node/Pattern-Rules.html#Pattern-Rules|title=GNU make manual: pattern rules|publisher=Free Software Foundation|access-date=2014-05-24|archive-date=2014-05-28|archive-url=https://web.archive.org/web/20140528170600/http://www.gnu.org/software/make/manual/html_node/Pattern-Rules.html#Pattern-Rules|url-status=live}}</ref>

A pattern rule looks like an ordinary rule, except that its target contains exactly one  {{code|%}} character within the string. The target is considered a pattern for matching file names: the {{code|%}} can match any substring of zero or more characters,<ref>[http://www.lehman.cuny.edu/cgi-bin/man-cgi?make+1 See section ''Pattern Matching Rules'' in the SunPro man page]  {{webarchive|url=https://web.archive.org/web/20140529103302/http://www.lehman.cuny.edu/cgi-bin/man-cgi?make%201 |date=May 29, 2014 }}</ref> while other characters match only themselves. The prerequisites likewise use {{code|%}} to show how their names relate to the target name.

The example above of a suffix rule would look like the following pattern rule:
<syntaxhighlight lang="make">
# From %.html to %.txt
%.txt : %.html 
	lynx -dump $< > $@
</syntaxhighlight>