setting a variable to be the result of severla shell commands...

[richard offer]

I'm trying to set a variable (build number) to be the result of several
commands, so far I have :-

# usage build-ver <upstream release number>
#
define build-ver
BUILD_NUM=$(shell [ -f .build_num ] && cat .build_num )
NUM=$(if $(BUILD_NUM),$(shell expr $(BUILD_NUM) + 1),1)
$(strip $(1)build$(NUM))
endef


REL=$(call build-ver,4)

all:: $(REL).fred # just for testing...


The intention being that if the file .build_num exists that the contents
are incremented by 1 and used to set REL, ie the first build would set REL
=  4build1, then, 4build2 etc (the code to write the result back to
.build_num is not shown).

Looking at the output of make -p, I'm getting....

make: *** No rule to make target `BUILD_NUM=
NUM=1
4build.fred', needed by `make.build'.  Stop.

Any thoughts ?


I could do all this in a external shell script, but I'd like to keep it in
the makefile if at all possible.

richard.


PS: using := instead of = gives me the error

Makefile:35: *** target pattern contains no `%'. 


-- 
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Richard Offer                     Technical Lead, Trust Technology, SGI
"Specialization is for insects"
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