From ffe659f94d793375fca97dd296422fc10c155016 Mon Sep 17 00:00:00 2001 From: Pierre Habouzit Date: Mon, 15 Oct 2007 01:45:45 +0200 Subject: [PATCH] parse-options: make some arguments optional, add callbacks. * add the possibility to use callbacks to parse some options, this can help implementing new options kinds with great flexibility. struct option gains a callback pointer and a `defval' where callbacks user can put either integers or pointers. callbacks also can use the `value' pointer for anything, preferably to the pointer to the final storage for the value though. * add a `flag' member to struct option to make explicit that this option may have an optional argument. The semantics depends on the option type. For INTEGERS, it means that if the switch is not used in its --long-form= form, and that there is no token after it or that the token does not starts with a digit, then it's assumed that the switch has no argument. For STRING or CALLBACK it works the same, except that the condition is that the next atom starts with a dash. This is needed to implement backward compatible behaviour with existing ways to parse the command line. Its use for new options is discouraged. Signed-off-by: Pierre Habouzit Signed-off-by: Shawn O. Pearce --- parse-options.c | 45 +++++++++++++++++++++++++++++++++++++-------- parse-options.h | 16 ++++++++++++++++ 2 files changed, 53 insertions(+), 8 deletions(-) diff --git a/parse-options.c b/parse-options.c index 89c5f52be..c751ebf60 100644 --- a/parse-options.c +++ b/parse-options.c @@ -39,7 +39,8 @@ static int opterror(const struct option *opt, const char *reason, int flags) static int get_value(struct optparse_t *p, const struct option *opt, int flags) { - const char *s; + const char *s, *arg; + arg = p->opt ? p->opt : (p->argc > 1 ? p->argv[1] : NULL); if (p->opt && (flags & OPT_UNSET)) return opterror(opt, "takes no value", flags); @@ -59,17 +60,34 @@ static int get_value(struct optparse_t *p, *(const char **)opt->value = (const char *)NULL; return 0; } - if (!p->opt && p->argc <= 1) + if (opt->flags & PARSE_OPT_OPTARG && (!arg || *arg == '-')) { + *(const char **)opt->value = (const char *)opt->defval; + return 0; + } + if (!arg) return opterror(opt, "requires a value", flags); *(const char **)opt->value = get_arg(p); return 0; + case OPTION_CALLBACK: + if (flags & OPT_UNSET) + return (*opt->callback)(opt, NULL, 1); + if (opt->flags & PARSE_OPT_OPTARG && (!arg || *arg == '-')) + return (*opt->callback)(opt, NULL, 0); + if (!arg) + return opterror(opt, "requires a value", flags); + return (*opt->callback)(opt, get_arg(p), 0); + case OPTION_INTEGER: if (flags & OPT_UNSET) { *(int *)opt->value = 0; return 0; } - if (!p->opt && p->argc <= 1) + if (opt->flags & PARSE_OPT_OPTARG && (!arg || !isdigit(*arg))) { + *(int *)opt->value = opt->defval; + return 0; + } + if (!arg) return opterror(opt, "requires a value", flags); *(int *)opt->value = strtol(get_arg(p), (char **)&s, 10); if (*s) @@ -201,13 +219,24 @@ void usage_with_options(const char * const *usagestr, switch (opts->type) { case OPTION_INTEGER: - pos += fprintf(stderr, " "); + if (opts->flags & PARSE_OPT_OPTARG) + pos += fprintf(stderr, " []"); + else + pos += fprintf(stderr, " "); break; case OPTION_STRING: - if (opts->argh) - pos += fprintf(stderr, " <%s>", opts->argh); - else - pos += fprintf(stderr, " ..."); + case OPTION_CALLBACK: + if (opts->argh) { + if (opts->flags & PARSE_OPT_OPTARG) + pos += fprintf(stderr, " [<%s>]", opts->argh); + else + pos += fprintf(stderr, " <%s>", opts->argh); + } else { + if (opts->flags & PARSE_OPT_OPTARG) + pos += fprintf(stderr, " [...]"); + else + pos += fprintf(stderr, " ..."); + } break; default: break; diff --git a/parse-options.h b/parse-options.h index 3006a769c..2b8e7624d 100644 --- a/parse-options.h +++ b/parse-options.h @@ -7,12 +7,20 @@ enum parse_opt_type { OPTION_BOOLEAN, OPTION_STRING, OPTION_INTEGER, + OPTION_CALLBACK, }; enum parse_opt_flags { PARSE_OPT_KEEP_DASHDASH = 1, }; +enum parse_opt_option_flags { + PARSE_OPT_OPTARG = 1, +}; + +struct option; +typedef int parse_opt_cb(const struct option *, const char *arg, int unset); + struct option { enum parse_opt_type type; int short_name; @@ -20,6 +28,12 @@ struct option { void *value; const char *argh; const char *help; + + int flags; + parse_opt_cb *callback; + /* holds default value for PARSE_OPT_OPTARG, + though callbacks can use it like they want */ + intptr_t defval; }; #define OPT_END() { OPTION_END } @@ -27,6 +41,8 @@ struct option { #define OPT_BOOLEAN(s, l, v, h) { OPTION_BOOLEAN, (s), (l), (v), NULL, (h) } #define OPT_INTEGER(s, l, v, h) { OPTION_INTEGER, (s), (l), (v), NULL, (h) } #define OPT_STRING(s, l, v, a, h) { OPTION_STRING, (s), (l), (v), (a), (h) } +#define OPT_CALLBACK(s, l, v, a, h, f) \ + { OPTION_CALLBACK, (s), (l), (v), (a), (h), 0, (f) } /* parse_options() will filter out the processed options and leave the * non-option argments in argv[]. -- 2.30.2