Re: [PATCH v3 03/12] bisect--helper: introduce new `write_in_file()` function

[Johannes Schindelin <Johannes.Schindelin@gmx.de>]

Hi Miriam,

On Thu, 23 Apr 2020, Miriam Rubio wrote:

> Let's refactor code adding a new `write_in_file()` function
> that opens a file for writing a message and closes it.

Don't we have that already?
https://github.com/git/git/blob/v2.27.0-rc1/wrapper.c#L625-L638

If that function does not meet the bill, it would make more sense to
extend it (or refactor it, providing a new global function that does meet
the bill).

> This helper will be used in later steps and makes the code
> simpler and easier to understand.

Makes a lot of sense to me!

> Mentored-by: Christian Couder <chriscool@tuxfamily.org>
> Mentored-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
> Signed-off-by: Miriam Rubio <mirucam@gmail.com>
> ---
>  builtin/bisect--helper.c | 29 +++++++++++++++++++++++------
>  1 file changed, 23 insertions(+), 6 deletions(-)
>
> diff --git a/builtin/bisect--helper.c b/builtin/bisect--helper.c
> index 0fbd924aac..d3b2b33df0 100644
> --- a/builtin/bisect--helper.c
> +++ b/builtin/bisect--helper.c
> @@ -74,6 +74,28 @@ static int one_of(const char *term, ...)
>  	return res;
>  }
>
> +static int write_in_file(const char *path, const char *mode, const char *format,...)

I wonder whether there is _ever_ a case where we want to set `mode` to
anything else than `"w"`? Ah...

> +{
> +	FILE *fp = NULL;
> +	va_list args;
> +	int res = 0;
> +
> +	if (!strcmp(mode, "a") && !strcmp(mode, "w"))
> +		return error(_("wrong writing mode '%s'"), mode);

... rather than doing this, I would prefer a pair of functions (that can
call the same helper function doing the actual work): `write_to_file()`
and `append_to_file()`.

Apart from that, the patch looks good to me,
Dscho

> +	fp = fopen(path, mode);
> +	if (!fp)
> +		return error_errno(_("cannot open file '%s' in mode '%s'"), path, mode);
> +	va_start(args, format);
> +	res = vfprintf(fp, format, args);
> +	va_end(args);
> +	if (!res) {
> +		fclose(fp);
> +		return error_errno(_("could not write to file '%s'"), path);
> +	}
> +
> +	return fclose(fp);
> +}
> +
>  static int check_term_format(const char *term, const char *orig_term)
>  {
>  	int res;
> @@ -104,7 +126,6 @@ static int check_term_format(const char *term, const char *orig_term)
>
>  static int write_terms(const char *bad, const char *good)
>  {
> -	FILE *fp = NULL;
>  	int res;
>
>  	if (!strcmp(bad, good))
> @@ -113,12 +134,8 @@ static int write_terms(const char *bad, const char *good)
>  	if (check_term_format(bad, "bad") || check_term_format(good, "good"))
>  		return -1;
>
> -	fp = fopen(git_path_bisect_terms(), "w");
> -	if (!fp)
> -		return error_errno(_("could not open the file BISECT_TERMS"));
> +	res = write_in_file(git_path_bisect_terms(), "w", "%s\n%s\n", bad, good);
>
> -	res = fprintf(fp, "%s\n%s\n", bad, good);
> -	res |= fclose(fp);
>  	return (res < 0) ? -1 : 0;
>  }
>
> --
> 2.25.0
>
>