One other small thing that may or may not be obvious: if your
estimationkmer.py script fails (returns non-zero), you won't be
notified (and ESTK will likely end up empty).
Paul, is there any chance of adding a different version of $(shell)
that fails noisily if the given shell command returns non-zero?
I often use this goofy function:
# This function works almost exactly like the built-in shell command, except it
# stops everything with an error if the shell command given as its argument
# returns non-zero when executed. The other difference is that the output
# is passed through the strip make function (the shell function strips
# only the last trailing newline). In practice this doesn't matter much
# since the output is usually collapsed by the surrounding make context
# to the same result produced by strip. WARNING: don't try to nest calls
# to this function.
SHELL_CHECKED = \
$(strip \
$(if $(shell (($1) 1>/tmp/SC_so) || echo 'non-empty'), \
$(error shell command '$1' failed. Its stderr should be above \
somewhere. Its stdout is available for review in '/tmp/SC_so'), \
$(shell cat /tmp/SC_so)))
Britton
On Wed, Mar 25, 2015 at 3:55 AM, Paul Smith <psm...@gnu.org> wrote:
> On Wed, 2015-03-25 at 02:54 -0700, guylobster wrote:
>> this is the first time I do a makefile.
>> But I block to assign the result of my python script to a variable of my
>> makefile.
>> The function works. Here the function and the result.
>>
>> *My makefile*
>> G_SIZE=10
>> Quake:
>> python estimationkmer.py $(G_SIZE)
>> ESTK=$(python estimationkmer.py $(G_SIZE))
>> echo $(ESTK)
>
> You have three problems here:
>
> First you have to escape dollar signs which you want to be passed to the
> shell:
>
> ESTK=$$(python estimationkmer.py $(G_SIZE))
>
> (note the double "$$" here) to escape the "$" so make passes it to your
> shell.
>
> The second problem is that make invokes every line of a recipe as a
> separate shell script, so variables assigned in one line are lost before
> the next line. If you want to set a shell variable and use it again you
> have to put both commands in the same shell:
>
> ESTK=$$(python estimationkmer.py $(G_SIZE)) ; \
> echo $$ESTK
>
> Finally, note this is setting a SHELL variable.
>
> You can't set a MAKE variable from within a recipe, because recipes are
> passed to the shell and run there. If you want to set a make variable
> you have to do it outside of a recipe, using make's shell function:
>
> ESTK := $(shell python estimationkmer.py $(G_SIZE))
>
> Quake:
> echo $(ESTK)
>
>
> _______________________________________________
> Help-make mailing list
> Help-make@gnu.org
> https://lists.gnu.org/mailman/listinfo/help-make
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