%% David Boyce <dsb@xxxxxxxxxx> writes:
>> According to POSIX, setting the SHELL make variable has _NO_ effect on
>> make's processing. The POSIX definition of make requires that all
>> commands be invoked "as if" passed directly to the system() function,
>> and there is no way to specify that the system() function would use a
>> different shell than the standard sh, of course.
>> The standard handles SHELL specially such that it doesn't inherit that
>> value from the environment nor put any make value for that variable back
>> into the environment of subcommands, but neither does it provide for
>> make to use the command provided by $(SHELL) rather than system() (or
>> sh).
db> Could you cite the relevant C&V please? I don't have access to
db> POSIX.1 (unless it's become freely available since I last looked?)
db> but SUSv3 says only this:
db> The SHELL macro shall be treated specially. It shall be provided by
db> make and set to the pathname of the shell command language
db> interpreter (see sh ). The SHELL environment variable shall not
db> affect the value of the SHELL macro. If SHELL is defined in the
db> makefile or is specified on the command line, it shall replace the
db> original value of the SHELL macro, but shall not affect the SHELL
db> environment variable. *Other effects of defining SHELL in the
db> makefile or on the command line are implementation-defined.*
db> (emphasis mine). Does POSIX flatly contradict this? Surprising if
db> true. And are you looking at a new or relatively old rev of POSIX?
No, this is what I mean.
I guess I wasn't quite clear above: I didn't mean that POSIX disallowed
what GNU make (and other makes) do with the SHELL variable.
I only meant that POSIX doesn't _require_ that setting SHELL would change
the way commands were invoked.
And in fact, elsewhere in the make standard it says explicitly:
Command execution shall be as if the makefile command line were the
argument to the system() function.
I suppose you could still do something like this:
system("$(SHELL) -c <command>");
and be conforming :).
--
-------------------------------------------------------------------------------
Paul D. Smith <psmith@xxxxxxx> Find some GNU make tips at:
http://www.gnu.org http://make.paulandlesley.org
"Please remain calm...I may be mad, but I am a professional." --Mad Scientist
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