examples/misc.m4 - m4 - Git at Google

 divert(-1)
 define(`HOST', `vale')
 define(`TMP', maketemp(`/tmp/hejXXXXXX'))
 syscmd(`ypmatch' HOST `hosts | awk "{print \$1}"'  > TMP)
 define(`IP', include(TMP))
 syscmd(`rm -f' TMP)
 divert

 IP
	divert(-1)
	define(`HOST', `vale')
	define(`TMP', maketemp(`/tmp/hejXXXXXX'))
	syscmd(`ypmatch' HOST `hosts \| awk "{print \$1}"' > TMP)
	define(`IP', include(TMP))
	syscmd(`rm -f' TMP)
	divert

	IP