| Message ID | 20200512234213.63651-2-emilyshaffer@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | bugreport: collect shell settings | expand |
On 2020-05-12 at 23:42:12, Emily Shaffer wrote: > It may be useful to know which shell Git was built to try to point to, > in the event that shell-based Git commands are failing. $SHELL_PATH is > set during the build and used to launch the manpage viewer, as well as > by git-compat-util.h, and it's used during tests. 'git version > --build-options' is encouraged for use in bug reports, so it makes sense > to include this information there. > > Signed-off-by: Emily Shaffer <emilyshaffer@google.com> > --- > help.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/help.c b/help.c > index 1de9c0d589..44cee69c11 100644 > --- a/help.c > +++ b/help.c > @@ -641,6 +641,7 @@ void get_version_info(struct strbuf *buf, int show_build_options) > strbuf_addstr(buf, "no commit associated with this build\n"); > strbuf_addf(buf, "sizeof-long: %d\n", (int)sizeof(long)); > strbuf_addf(buf, "sizeof-size_t: %d\n", (int)sizeof(size_t)); > + strbuf_addf(buf, "shell-path: %s\n", SHELL_PATH); > /* NEEDSWORK: also save and output GIT-BUILD_OPTIONS? */ > } > } This seems straightforward and logical (as does the rest of the series), but I wondered if it might be a good idea to try to interrogate the shell for more information. The reason I mention it is that Debian permits any shell that meets certain standards to be /bin/sh, and all programs that invoke /bin/sh must depend on only those features. The default is dash, but people could use bash, which is more featureful, or posh, which is intentionally designed to provide the bare minimum /bin/sh experience[0], among others. A value of "/bin/sh" doesn't necessarily tell us very much on Debian (or on macOS, for that matter). Now, that of course does mean that we have to have some way to distinguish between shells, and that is the hard part, so I'm completely fine with us leaving it out until we have a good way to do it (or until we decide we need it, which may be never). I just wanted to mention it as a potential approach for the future. I'm happy with this series as it stands right now. [0] Quite literally, in that it's supposed to be a tool for testing compatibility with the policy requirements.
"brian m. carlson" <sandals@crustytoothpaste.net> writes: > This seems straightforward and logical (as does the rest of the series), > but I wondered if it might be a good idea to try to interrogate the > shell for more information. The reason I mention it is that Debian > permits any shell that meets certain standards to be /bin/sh, and all > programs that invoke /bin/sh must depend on only those features. The > default is dash, but people could use bash, which is more featureful, or > posh, which is intentionally designed to provide the bare minimum > /bin/sh experience[0], among others. A value of "/bin/sh" doesn't > necessarily tell us very much on Debian (or on macOS, for that matter). Good point. Perhaps readlink(3) on it, then? lrwxrwxrwx 1 root root 9 Mar 11 2018 /bin/sh -> /bin/bash > Now, that of course does mean that we have to have some way to > distinguish between shells, and that is the hard part, so I'm completely > fine with us leaving it out until we have a good way to do it (or until > we decide we need it, which may be never). I just wanted to mention it > as a potential approach for the future. I'm happy with this series as > it stands right now. > > [0] Quite literally, in that it's supposed to be a tool for testing > compatibility with the policy requirements.
On Wed, May 13, 2020 at 1:02 AM Junio C Hamano <gitster@pobox.com> wrote: > "brian m. carlson" <sandals@crustytoothpaste.net> writes: > > [...] A value of "/bin/sh" doesn't > > necessarily tell us very much on Debian (or on macOS, for that matter). > > Good point. Perhaps readlink(3) on it, then? > > lrwxrwxrwx 1 root root 9 Mar 11 2018 /bin/sh -> /bin/bash That wouldn't help on Mac OS: $ ls -l /bin/sh /bin/bash -r-xr-xr-x 1 root wheel 618448 Mar 18 22:04 /bin/bash -r-xr-xr-x 1 root wheel 618512 Mar 18 22:04 /bin/sh Although /bin/sh is neither a hard link nor a symbolic link to /bin/bash, nor is the file size the same, it is nevertheless Bash (in some form or another).
On Wed, May 13, 2020 at 01:10:36AM -0400, Eric Sunshine wrote: > > On Wed, May 13, 2020 at 1:02 AM Junio C Hamano <gitster@pobox.com> wrote: > > "brian m. carlson" <sandals@crustytoothpaste.net> writes: > > > [...] A value of "/bin/sh" doesn't > > > necessarily tell us very much on Debian (or on macOS, for that matter). > > > > Good point. Perhaps readlink(3) on it, then? > > > > lrwxrwxrwx 1 root root 9 Mar 11 2018 /bin/sh -> /bin/bash > > That wouldn't help on Mac OS: > > $ ls -l /bin/sh /bin/bash > -r-xr-xr-x 1 root wheel 618448 Mar 18 22:04 /bin/bash > -r-xr-xr-x 1 root wheel 618512 Mar 18 22:04 /bin/sh > > Although /bin/sh is neither a hard link nor a symbolic link to > /bin/bash, nor is the file size the same, it is nevertheless Bash (in > some form or another). Hum. It seems some useful things exist like $BASH_VERSION and $ZSH_VERSION, but I'm not terribly excited about the idea of making a list and checking each one in bugreport (as it's sure to be nonexhaustive). I found a few more heuristics in a SO post[1] but this approach generally looks like a pain, and somewhat unreliable. Most other alternatives I found with a cursory Google involve checking the name of the shell, which I think will have the same issues as checking $SHELL: - `ps -p $$` for info about the current process (didn't reveal bash when I `cp /bin/bash ~/bin/nish && ~/bin/nish`) - `echo $0` since it's coming from the command line, of course will be the same as $SHELL I suppose if we wanted to do the heuristics it'd be a better experience for us, the bugreport receivers, to have the bugreport library collect the heuristics and try to make a guess, rather than just dump all the heuristics and let the humans try to remember which shell has $PS4 and which shell has $version and so on. But to me that sounds prone to rot at best. - Emily [1]: https://stackoverflow.com/a/3327022
diff --git a/help.c b/help.c index 1de9c0d589..44cee69c11 100644 --- a/help.c +++ b/help.c @@ -641,6 +641,7 @@ void get_version_info(struct strbuf *buf, int show_build_options) strbuf_addstr(buf, "no commit associated with this build\n"); strbuf_addf(buf, "sizeof-long: %d\n", (int)sizeof(long)); strbuf_addf(buf, "sizeof-size_t: %d\n", (int)sizeof(size_t)); + strbuf_addf(buf, "shell-path: %s\n", SHELL_PATH); /* NEEDSWORK: also save and output GIT-BUILD_OPTIONS? */ } }
It may be useful to know which shell Git was built to try to point to, in the event that shell-based Git commands are failing. $SHELL_PATH is set during the build and used to launch the manpage viewer, as well as by git-compat-util.h, and it's used during tests. 'git version --build-options' is encouraged for use in bug reports, so it makes sense to include this information there. Signed-off-by: Emily Shaffer <emilyshaffer@google.com> --- help.c | 1 + 1 file changed, 1 insertion(+)