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authorPierre Habouzit <madcoder@debian.org>2007-10-14 23:35:37 (GMT)
committerJunio C Hamano <gitster@pobox.com>2007-10-30 04:03:30 (GMT)
commit4a59fd131229968b08af9bdf221c341f54c52983 (patch)
treea8ef53eb16f801c0aee2dde11f6dee7c283e170a /parse-options.c
parent09149c7809a37a52b38d8d7a0621e2fb8943d8fe (diff)
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Add a simple option parser.
The option parser takes argc, argv, an array of struct option and a usage string. Each of the struct option elements in the array describes a valid option, its type and a pointer to the location where the value is written. The entry point is parse_options(), which scans through the given argv, and matches each option there against the list of valid options. During the scan, argv is rewritten to only contain the non-option command line arguments and the number of these is returned. Aggregation of single switches is allowed: -rC0 is the same as -r -C 0 (supposing that -C wants an arg). Every long option automatically support the option with the same name, prefixed with 'no-' to unset the switch. It assumes that initial value for strings are "NULL" and for integers is "0". Long options are supported either with '=' or without: --some-option=foo is the same as --some-option foo Acked-by: Kristian Høgsberg <krh@redhat.com> Signed-off-by: Pierre Habouzit <madcoder@debian.org> Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Diffstat (limited to 'parse-options.c')
-rw-r--r--parse-options.c167
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;
+}