| Message ID | 20240214180039.57527-1-anthony.perard@citrix.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [XEN,v2] build: Replace `which` with `command -v` | expand |
On 14/02/2024 6:00 pm, Anthony PERARD wrote: > The `which` command is not standard, may not exist on the build host, > or may not behave as expected by the build system. It is recommended > to use `command -v` to find out if a command exist and have its path, > and it's part of a POSIX shell standard (at least, it seems to be > mandatory since IEEE Std 1003.1-2008, but was optional before). > > Signed-off-by: Anthony PERARD <anthony.perard@citrix.com> > Tested-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com> Acked-by: Andrew Cooper <andrew.cooper3@citrix.com> I expect we want fixes tags for c8a8645f1ef (python) and 3b47bcdb6d383 (figlet). Both my fault it turns out... Happy to fix on commit. ~Andrew
On 14.02.2024 19:00, Anthony PERARD wrote: > The `which` command is not standard, may not exist on the build host, > or may not behave as expected by the build system. It is recommended > to use `command -v` to find out if a command exist and have its path, > and it's part of a POSIX shell standard (at least, it seems to be > mandatory since IEEE Std 1003.1-2008, but was optional before). > > Signed-off-by: Anthony PERARD <anthony.perard@citrix.com> > Tested-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com> Reviewed-by: Jan Beulich <jbeulich@suse.com>
On Wed, Feb 14, 2024 at 06:06:38PM +0000, Andrew Cooper wrote: > On 14/02/2024 6:00 pm, Anthony PERARD wrote: > > The `which` command is not standard, may not exist on the build host, > > or may not behave as expected by the build system. It is recommended > > to use `command -v` to find out if a command exist and have its path, > > and it's part of a POSIX shell standard (at least, it seems to be > > mandatory since IEEE Std 1003.1-2008, but was optional before). > > > > Signed-off-by: Anthony PERARD <anthony.perard@citrix.com> > > Tested-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com> > > Acked-by: Andrew Cooper <andrew.cooper3@citrix.com> > > I expect we want fixes tags for c8a8645f1ef (python) and 3b47bcdb6d383 > (figlet). Both my fault it turns out... Sounds good. I saw this patch as an improvement rather than a bug fix so I didn't think about fixes tags. It's one less build dependency, so I guess it's nice to have and backport. It's common to use `which` to find a path to a binary, and unfortunately not well known that `command -v` is a more portable alternative. So not exactly your fault. It's looks like there's a nice write up about this here: https://unix.stackexchange.com/questions/85249/why-not-use-which-what-to-use-then/85250#85250 Cheers,
diff --git a/xen/Makefile b/xen/Makefile index 21832d6402..767e47d6c7 100644 --- a/xen/Makefile +++ b/xen/Makefile @@ -25,8 +25,8 @@ export XEN_BUILD_HOST := $(shell hostname) endif # Best effort attempt to find a python interpreter, defaulting to Python 3 if -# available. Fall back to just `python` if `which` is nowhere to be found. -PYTHON_INTERPRETER := $(word 1,$(shell which python3 python python2 2>/dev/null) python) +# available. Fall back to just `python`. +PYTHON_INTERPRETER := $(word 1,$(shell command -v python3 || command -v python || command -v python2) python) export PYTHON ?= $(PYTHON_INTERPRETER) export CHECKPOLICY ?= checkpolicy diff --git a/xen/build.mk b/xen/build.mk index 26dd5a8e87..0f490ca71b 100644 --- a/xen/build.mk +++ b/xen/build.mk @@ -1,6 +1,6 @@ quiet_cmd_banner = BANNER $@ define cmd_banner - if which figlet >/dev/null 2>&1 ; then \ + if command -v figlet >/dev/null 2>&1 ; then \ echo " Xen $(XEN_FULLVERSION)" | figlet -f $< > $@.tmp; \ else \ echo " Xen $(XEN_FULLVERSION)" > $@.tmp; \