On Thu, Jun 22, 2023 at 4:03 PM brian m. carlson
<sandals@xxxxxxxxxxxxxxxxxxxx> wrote:
> On most Unix systems, finding a suitable shell is easy: one simply uses
> "sh" with an appropriate PATH value. However, in many Windows
> environments, the shell is shipped alongside Git, and it may or may not
> be in PATH, even if Git is.
>
> In such an environment, it can be very helpful to query Git for the
> shell it's using, since other tools may want to use the same shell as
> well. To help them out, let's add a variable, GIT_SHELL_PATH, that
> points to the location of the shell.
>
> On Unix, we know our shell must be executable to be functional, so
> assume that the distributor has correctly configured their environment,
> and use that as a basic test. On Git for Windows, we know that our
> shell will be one of a few fixed values, all of which end in "sh" (such
> as "bash"). This seems like it might be a nice test on Unix as well,
> since it is customary for all shells to end in "sh", but there probably
> exist such systems that don't have such a configuration, so be careful
> here not to break them.
>
> Signed-off-by: brian m. carlson <bk2204@xxxxxxxxxx>
> ---
> diff --git a/t/t0007-git-var.sh b/t/t0007-git-var.sh
> @@ -147,6 +147,18 @@ test_expect_success 'get GIT_SEQUENCE_EDITOR with configuration and environment
> +test_expect_success POSIXPERM 'GIT_SHELL_PATH points to a valid executable' '
> + git var GIT_SHELL_PATH >shell &&
> + test -x "$(cat shell)"
> +'
This can be implemented more simply without a temporary file:
shpath=$(git var GIT_SHELL_PATH) &&
test -x "$shpath"
This is safe since the exit code of the Git command is preserved
across the `shpath=...` assignment.
> +# We know in this environment that our shell will be one of a few fixed values
> +# that all end in "sh".
> +test_expect_success MINGW 'GIT_SHELL_PATH points to a suitable shell' '
> + git var GIT_SHELL_PATH >shell &&
> + grep "sh\$" shell
> +'
Similarly, there is no need for a temporary file or an extra process.
This can all be done entirely in the shell itself:
shpath=$(git var GIT_SHELL_PATH) &&
case "$shpath" in
*sh) ;;
*) return 1
esac
