diff options
Diffstat (limited to 'parse-options.c')
| -rw-r--r-- | parse-options.c | 167 |
1 files changed, 167 insertions, 0 deletions
diff --git a/parse-options.c b/parse-options.c new file mode 100644 index 0000000..7bdffdb --- /dev/null +++ b/parse-options.c @@ -0,0 +1,167 @@ +#include "git-compat-util.h" +#include "parse-options.h" +#include "strbuf.h" + +#define OPT_SHORT 1 +#define OPT_UNSET 2 + +struct optparse_t { + const char **argv; + int argc; + const char *opt; +}; + +static inline const char *get_arg(struct optparse_t *p) +{ + if (p->opt) { + const char *res = p->opt; + p->opt = NULL; + return res; + } + p->argc--; + return *++p->argv; +} + +static inline const char *skip_prefix(const char *str, const char *prefix) +{ + size_t len = strlen(prefix); + return strncmp(str, prefix, len) ? NULL : str + len; +} + +static int opterror(const struct option *opt, const char *reason, int flags) +{ + if (flags & OPT_SHORT) + return error("switch `%c' %s", opt->short_name, reason); + if (flags & OPT_UNSET) + return error("option `no-%s' %s", opt->long_name, reason); + return error("option `%s' %s", opt->long_name, reason); +} + +static int get_value(struct optparse_t *p, + const struct option *opt, int flags) +{ + const char *s; + + if (p->opt && (flags & OPT_UNSET)) + return opterror(opt, "takes no value", flags); + + switch (opt->type) { + case OPTION_BOOLEAN: + if (!(flags & OPT_SHORT) && p->opt) + return opterror(opt, "takes no value", flags); + if (flags & OPT_UNSET) + *(int *)opt->value = 0; + else + (*(int *)opt->value)++; + return 0; + + case OPTION_STRING: + if (flags & OPT_UNSET) { + *(const char **)opt->value = (const char *)NULL; + return 0; + } + if (!p->opt && p->argc <= 1) + return opterror(opt, "requires a value", flags); + *(const char **)opt->value = get_arg(p); + return 0; + + case OPTION_INTEGER: + if (flags & OPT_UNSET) { + *(int *)opt->value = 0; + return 0; + } + if (!p->opt && p->argc <= 1) + return opterror(opt, "requires a value", flags); + *(int *)opt->value = strtol(get_arg(p), (char **)&s, 10); + if (*s) + return opterror(opt, "expects a numerical value", flags); + return 0; + + default: + die("should not happen, someone must be hit on the forehead"); + } +} + +static int parse_short_opt(struct optparse_t *p, const struct option *options) +{ + for (; options->type != OPTION_END; options++) { + if (options->short_name == *p->opt) { + p->opt = p->opt[1] ? p->opt + 1 : NULL; + return get_value(p, options, OPT_SHORT); + } + } + return error("unknown switch `%c'", *p->opt); +} + +static int parse_long_opt(struct optparse_t *p, const char *arg, + const struct option *options) +{ + for (; options->type != OPTION_END; options++) { + const char *rest; + int flags = 0; + + if (!options->long_name) + continue; + + rest = skip_prefix(arg, options->long_name); + if (!rest) { + if (strncmp(arg, "no-", 3)) + continue; + flags |= OPT_UNSET; + rest = skip_prefix(arg + 3, options->long_name); + if (!rest) + continue; + } + if (*rest) { + if (*rest != '=') + continue; + p->opt = rest + 1; + } + return get_value(p, options, flags); + } + return error("unknown option `%s'", arg); +} + +int parse_options(int argc, const char **argv, const struct option *options, + const char *usagestr, int flags) +{ + struct optparse_t args = { argv + 1, argc - 1, NULL }; + int j = 0; + + for (; args.argc; args.argc--, args.argv++) { + const char *arg = args.argv[0]; + + if (*arg != '-' || !arg[1]) { + argv[j++] = args.argv[0]; + continue; + } + + if (arg[1] != '-') { + args.opt = arg + 1; + do { + if (*args.opt == 'h') + usage(usagestr); + if (parse_short_opt(&args, options) < 0) + usage(usagestr); + } while (args.opt); + continue; + } + + if (!arg[2]) { /* "--" */ + if (!(flags & PARSE_OPT_KEEP_DASHDASH)) { + args.argc--; + args.argv++; + } + break; + } + + if (!strcmp(arg + 2, "help")) + usage(usagestr); + if (parse_long_opt(&args, arg + 2, options)) + usage(usagestr); + } + + memmove(argv + j, args.argv, args.argc * sizeof(*argv)); + argv[j + args.argc] = NULL; + return j + args.argc; +} |