@matheusbsbs / matheus-bagliano / commits / afaef55e23

git-compat-util: introduce skip_to_optional_arg()

We often accept both a "--key" option and a "--key=<val>" option. These options currently are parsed using something like: if (!strcmp(arg, "--key")) { /* do something */ } else if (skip_prefix(arg, "--key=", &arg)) { /* do something with arg */ } which is a bit cumbersome compared to just: if (skip_to_optional_arg(arg, "--key", &arg)) { /* do something with arg */ } This also introduces skip_to_optional_arg_default() for the few cases where something different should be done when the first argument is exactly "--key" than when it is exactly "--key=". In general it is better for UI consistency and simplicity if "--key" and "--key=" do the same thing though, so that using skip_to_optional_arg() should be encouraged compared to skip_to_optional_arg_default(). Note that these functions can be used to parse any "key=value" string where "key" is also considered as valid, not just command line options. Signed-off-by: Christian Couder <chriscool@tuxfamily.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Christian Couder committed Dec 9, 2017 at 21:40 UTC afaef55e230c6fcfb4e8a27c1b970f7e6400a7f6
2 files changed +45
git-compat-util.h
+23
@@ -484,6 +484,29 @@ static inline int skip_prefix(const char *str, const char *prefix,
484 return 0;
485 }
486
487 +/*
488 + * If the string "str" is the same as the string in "prefix", then the "arg"
489 + * parameter is set to the "def" parameter and 1 is returned.
490 + * If the string "str" begins with the string found in "prefix" and then a
491 + * "=" sign, then the "arg" parameter is set to "str + strlen(prefix) + 1"
492 + * (i.e., to the point in the string right after the prefix and the "=" sign),
493 + * and 1 is returned.
494 + *
495 + * Otherwise, return 0 and leave "arg" untouched.
496 + *
497 + * When we accept both a "--key" and a "--key=<val>" option, this function
498 + * can be used instead of !strcmp(arg, "--key") and then
499 + * skip_prefix(arg, "--key=", &arg) to parse such an option.
500 + */
501 +int skip_to_optional_arg_default(const char *str, const char *prefix,
502 + const char **arg, const char *def);
503 +
504 +static inline int skip_to_optional_arg(const char *str, const char *prefix,
505 + const char **arg)
506 +{
507 + return skip_to_optional_arg_default(str, prefix, arg, "");
508 +}
509 +
510 /*
511 * Like skip_prefix, but promises never to read past "len" bytes of the input
512 * buffer, and returns the remaining number of bytes in "out" via "outlen".
strbuf.c
+22
@@ -11,6 +11,28 @@ int starts_with(const char *str, const char *prefix)
11 return 0;
12 }
13
14 +int skip_to_optional_arg_default(const char *str, const char *prefix,
15 + const char **arg, const char *def)
16 +{
17 + const char *p;
18 +
19 + if (!skip_prefix(str, prefix, &p))
20 + return 0;
21 +
22 + if (!*p) {
23 + if (arg)
24 + *arg = def;
25 + return 1;
26 + }
27 +
28 + if (*p != '=')
29 + return 0;
30 +
31 + if (arg)
32 + *arg = p + 1;
33 + return 1;
34 +}
35 +
36 /*
37 * Used as the default ->buf value, so that people can always assume
38 * buf is non NULL and ->buf is NUL terminated even for a freshly