1*148ee845SSimon J. Gerraty# $NetBSD: varname-dollar.mk,v 1.4 2023/06/01 20:56:35 rillig Exp $ 22c3632d1SSimon J. Gerraty# 32c3632d1SSimon J. Gerraty# Tests for the expression "$$", which looks as if it referred to a variable, 42c3632d1SSimon J. Gerraty# but simply expands to a single '$' sign. 52c3632d1SSimon J. Gerraty# 62c3632d1SSimon J. Gerraty# If there really were a special variable named '$', the expressions ${${DOLLAR}} 72c3632d1SSimon J. Gerraty# and $$ would always expand to the same value. 82c3632d1SSimon J. Gerraty 92c3632d1SSimon J. Gerraty# Using the dollar sign in variable names is tricky and not recommended. 102c3632d1SSimon J. Gerraty# To see that using this variable indeed affects the variable '$', run the 112c3632d1SSimon J. Gerraty# test individually with the -dv option. 122c3632d1SSimon J. GerratyDOLLAR= $$ 132c3632d1SSimon J. Gerraty 142c3632d1SSimon J. Gerraty# At this point, the variable '$' is not defined. Therefore the second line 152c3632d1SSimon J. Gerraty# returns an empty string. 16*148ee845SSimon J. Gerraty# expect+1: dollar is $. 172c3632d1SSimon J. Gerraty.info dollar is $$. 18*148ee845SSimon J. Gerraty# expect+1: dollar in braces is . 192c3632d1SSimon J. Gerraty.info dollar in braces is ${${DOLLAR}}. 202c3632d1SSimon J. Gerraty 212c3632d1SSimon J. Gerraty# Now overwrite the '$' variable to see whether '$$' really expands to that 222c3632d1SSimon J. Gerraty# variable, or whether '$$' is handled by the parser. 232c3632d1SSimon J. Gerraty${DOLLAR}= dollar 242c3632d1SSimon J. Gerraty 252c3632d1SSimon J. Gerraty# At this point, the variable '$' is defined, therefore its value is printed 262c3632d1SSimon J. Gerraty# in the second .info directive. 27*148ee845SSimon J. Gerraty# expect+1: dollar is $. 282c3632d1SSimon J. Gerraty.info dollar is $$. 29*148ee845SSimon J. Gerraty# expect+1: dollar in braces is dollar. 302c3632d1SSimon J. Gerraty.info dollar in braces is ${${DOLLAR}}. 312c3632d1SSimon J. Gerraty 322c3632d1SSimon J. Gerratyall: 332c3632d1SSimon J. Gerraty @:; 34