Subject: Re: [PATCH v3 09/10] various *.c: use isatty(1|2), not isatty(STDIN_FILENO|STDERR_FILENO)

From: Emily Shaffer <[email-masked]>
Date: Thu, 21 Oct 2021 20:39:31 -0700

On Thu, Oct 14, 2021 at 12:28:25AM +0200, Ævar Arnfjörð Bjarmason wrote:
> 
> We have over 50 uses of "isatty(1)" and "isatty(2)" in the codebase,
> only these two used the stdlib.h macros to refer to them.
> 
> Let's change these for consistency, and because a subsequent commit's
> commit message outlines a recipe to change all of these for ad-hoc
> testing, not needing to match these with that ad-hoc regex will make
> things easier to explain.
> 
> Signed-off-by: Ævar Arnfjörð Bjarmason <[email-masked]>

Usually I'd really rather see this go the other way and reduce the
number of "magic numbers" in the codebase, but I think file handles are
pretty well-known, so I guess for the sake of brevity it's ok...

Reviewed-by: Emily Shaffer <[email-masked]>

> ---
>  builtin/bisect--helper.c | 2 +-
>  builtin/bundle.c         | 2 +-
>  compat/mingw.c           | 2 +-
>  3 files changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/builtin/bisect--helper.c b/builtin/bisect--helper.c
> index 28a2e6a5750..1727cb051fb 100644
> --- a/builtin/bisect--helper.c
> +++ b/builtin/bisect--helper.c
> @@ -830,7 +830,7 @@ static int bisect_autostart(struct bisect_terms *terms)
>  	fprintf_ln(stderr, _("You need to start by \"git bisect "
>  			  "start\"\n"));
>  
> -	if (!isatty(STDIN_FILENO))
> +	if (!isatty(1))
>  		return -1;
>  
>  	/*
> diff --git a/builtin/bundle.c b/builtin/bundle.c
> index 5a85d7cd0fe..df69c651753 100644
> --- a/builtin/bundle.c
> +++ b/builtin/bundle.c
> @@ -56,7 +56,7 @@ static int parse_options_cmd_bundle(int argc,
>  
>  static int cmd_bundle_create(int argc, const char **argv, const char *prefix) {
>  	int all_progress_implied = 0;
> -	int progress = isatty(STDERR_FILENO);
> +	int progress = isatty(2);
>  	struct strvec pack_opts;
>  	int version = -1;
>  	int ret;
> diff --git a/compat/mingw.c b/compat/mingw.c
> index 9e0cd1e097f..0f545c1a7d1 100644
> --- a/compat/mingw.c
> +++ b/compat/mingw.c
> @@ -2374,7 +2374,7 @@ int mingw_raise(int sig)
>  	switch (sig) {
>  	case SIGALRM:
>  		if (timer_fn == SIG_DFL) {
> -			if (isatty(STDERR_FILENO))
> +			if (isatty(2))
>  				fputs("Alarm clock\n", stderr);
>  			exit(128 + SIGALRM);
>  		} else if (timer_fn != SIG_IGN)
> -- 
> 2.33.1.1346.g48288c3c089
>