Take the following makefile snippet:
VAR_LIST = "item1" "item2" "item 3 that has spaces" "item4"
ARGS = $(addprefix echo ,$(VAR_LIST))
What I am trying to achive is for ARGS to contain:
echo "item1" echo "item2" echo "item 3 that has spaces" echo "item4"
What I can't figure out how to resolve is that functions like addprefix act on spaces...
Not sure whether what you need is easily achievable with make because quoting strings have no effect on make functions that process words: " is a part of a word.
I would use a shell or python script for that.
You can do that with the help of gmtt entirely inside GNUmake. It is not as straightforward as in a full programming language, but at least it is portable and independent of external shell flavours and tools.
include gmtt/gmtt.mk
VAR_LIST = "item1" "item2" "item 3 that has spaces" "item4"
# make a prefix-list by splitting at ". This will yield superfluous space
# characters between the items, but we can eliminate them later
prefix-list := $(call chop-str-spc,$(VAR_LIST),A $(-alnum-as-str))
$(info $(prefix-list))
# Now we select the data payload from the prefix-list. Spaces inside items
# are still encoded as $(-spacereplace) characters, which is good as we have
# a normal make list this way
string-list := $(call get-sufx-val,$(prefix-list),A,,100)
$(info $(string-list))
# Using get-sufx-val() is fine, but we can have it even simpler, by dropping
# the prefix, as we have only one in the list anyway:
string-list := $(call drop-prfx,$(prefix-list))
# Now step through the list with a normal for loop, converting $(-spacereplace)
# back to real spaces
$(foreach item,$(string-list),$(if $(strip $(call spc-unmask,$(item))),\
$(info [$(call spc-unmask,$(item))])))
Output:
$ make
A¤item1 A¤§ A¤item2 A¤§ A¤item§3§that§has§spaces A¤§ A¤item4
item1 § item2 § item§3§that§has§spaces § item4
[item1]
[item2]
[item 3 that has spaces]
[item4]
"VAR=Some Value". Then I need to convert each of those into something that looks like:; echo "VAR=Some Value", where semicolon is the list seperator. Then I pipe that into the doxygen command. See first answer here: stackoverflow.com/questions/11032280/…. Does that make sense?; echo "VAR=some value"... but that looks like a horrible syntax to impose on the user... At the moment I am saying they can use only values without spaces (which is mostly ok).