1# $NetBSD: varmod-shell.mk,v 1.10 2024/07/05 19:47:22 rillig Exp $ 2# 3# Tests for the ':!cmd!' variable modifier, which runs the shell command 4# given by the variable modifier and returns its output. 5# 6# This modifier has been added on 2000-04-29. 7# 8# See also: 9# ApplyModifier_ShellCommand 10 11# The command to be run is enclosed between exclamation marks. 12# The previous value of the expression is irrelevant for this modifier. 13# The :!cmd! modifier turns an undefined expression into a defined one. 14.if ${:!echo word!} != "word" 15. error 16.endif 17 18# If the command exits with non-zero, an error message is printed. 19# XXX: Processing continues as usual though. 20# 21# Between 2000-04-29 and 2020-11-17, the error message mentioned the previous 22# value of the expression (which is usually an empty string) instead of the 23# command that was executed. 24# expect+1: warning: while evaluating "${:!echo word; (exit 13)!} != "word"" with value "word": Command "echo word; (exit 13)" exited with status 13 25.if ${:!echo word; (exit 13)!} != "word" 26. error 27.endif 28# expect+1: warning: while evaluating "${:Uprevious value:!echo word; (exit 13)!} != "word"" with value "word": Command "echo word; (exit 13)" exited with status 13 29.if ${:Uprevious value:!echo word; (exit 13)!} != "word" 30. error 31.endif 32 33 34.MAKEFLAGS: -dv # to see the "Capturing" debug output 35# expect+1: warning: while evaluating "${:!echo word; ${:U(exit 13)}!}" with value "word": Command "echo word; (exit 13)" exited with status 13 36_:= ${:!echo word; ${:U(exit 13)}!} 37.MAKEFLAGS: -d0 38 39 40all: 41