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
Also be able to generate the usage automatically.
Acked-by: Kristian Høgsberg <krh@xxxxxxxxxx>
Signed-off-by: Pierre Habouzit <madcoder@xxxxxxxxxx>
---
Makefile | 2 +-
parse-options.c | 227 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
parse-options.h | 37 +++++++++
3 files changed, 265 insertions(+), 1 deletions(-)
create mode 100644 parse-options.c
create mode 100644 parse-options.h
diff --git a/Makefile b/Makefile
index 62bdac6..d90e959 100644
--- a/Makefile
+++ b/Makefile
@@ -310,7 +310,7 @@ LIB_OBJS = \
alloc.o merge-file.o path-list.o help.o unpack-trees.o $(DIFF_OBJS) \
color.o wt-status.o archive-zip.o archive-tar.o shallow.o utf8.o \
convert.o attr.o decorate.o progress.o mailmap.o symlinks.o remote.o \
- transport.o bundle.o
+ transport.o bundle.o parse-options.o
BUILTIN_OBJS = \
builtin-add.o \
diff --git a/parse-options.c b/parse-options.c
new file mode 100644
index 0000000..07abb50
--- /dev/null
+++ b/parse-options.c
@@ -0,0 +1,227 @@
+#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 *skippfx(const char *str, const char *prefix)
+{
+ size_t len = strlen(prefix);
+ return strncmp(str, prefix, len) ? NULL : str + len;
+}
+
+static int opterror(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, struct option *opt, int flags)
+{
+ 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;
+ } else {
+ 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;
+ } else {
+ const char *s;
+ if (!p->opt && p->argc < 1)
+ return opterror(opt, "requires a value", flags);
+ *(int *)opt->value = strtol(*p->argv, (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, struct option *options, int count)
+{
+ int i;
+
+ for (i = 0; i < count; i++) {
+ if (options[i].short_name == *p->opt) {
+ p->opt = p->opt[1] ? p->opt + 1 : NULL;
+ return get_value(p, options + i, OPT_SHORT);
+ }
+ }
+ return error("unknown switch `%c'", *p->opt);
+}
+
+static int parse_long_opt(struct optparse_t *p, const char *arg,
+ struct option *options, int count)
+{
+ int i;
+
+ for (i = 0; i < count; i++) {
+ const char *rest;
+ int flags = 0;
+
+ if (!options[i].long_name)
+ continue;
+
+ rest = skippfx(arg, options[i].long_name);
+ if (!rest && !strncmp(arg, "no-", 3)) {
+ rest = skippfx(arg + 3, options[i].long_name);
+ flags |= OPT_SHORT;
+ }
+ if (!rest)
+ continue;
+ if (*rest) {
+ if (*rest != '=')
+ continue;
+ p->opt = rest + 1;
+ }
+ return get_value(p, options + i, flags);
+ }
+ return error("unknown option `%s'", arg);
+}
+
+int parse_options(int argc, const char **argv,
+ struct option *options, int count,
+ const char * const usagestr[], int flags)
+{
+ struct optparse_t optp = { argv + 1, argc - 1, NULL };
+ int j = 0;
+
+ for (; optp.argc; optp.argc--, optp.argv++) {
+ const char *arg = optp.argv[0];
+
+ if (*arg != '-' || !arg[1]) {
+ argv[j++] = optp.argv[0];
+ continue;
+ }
+
+ if (arg[1] != '-') {
+ optp.opt = arg + 1;
+ do {
+ if (*optp.opt == 'h')
+ make_usage(usagestr, options, count);
+ if (parse_short_opt(&optp, options, count) < 0)
+ make_usage(usagestr, options, count);
+ } while (optp.opt);
+ continue;
+ }
+
+ if (!arg[2]) { /* "--" */
+ if (!(flags & OPT_COPY_DASHDASH))
+ optp.argc--, optp.argv++;
+ break;
+ }
+
+ if (!strcmp(arg + 2, "help"))
+ make_usage(usagestr, options, count);
+ if (parse_long_opt(&optp, arg + 2, options, count))
+ make_usage(usagestr, options, count);
+ }
+
+ memmove(argv + j, optp.argv, optp.argc * sizeof(argv));
+ argv[j + optp.argc] = NULL;
+ return j + optp.argc;
+}
+
+#define USAGE_OPTS_WIDTH 24
+#define USAGE_GAP 2
+
+void make_usage(const char * const usagestr[], struct option *opts, int cnt)
+{
+ struct strbuf sb;
+
+ strbuf_init(&sb, 4096);
+ do {
+ strbuf_addstr(&sb, *usagestr++);
+ strbuf_addch(&sb, '\n');
+ } while (*usagestr);
+
+ if (cnt && opts->type != OPTION_GROUP)
+ strbuf_addch(&sb, '\n');
+
+ for (; cnt-- > 0; opts++) {
+ size_t pos;
+
+ if (opts->type == OPTION_GROUP) {
+ strbuf_addch(&sb, '\n');
+ if (*opts->help)
+ strbuf_addf(&sb, "%s\n", opts->help);
+ continue;
+ }
+
+ pos = sb.len;
+ strbuf_addstr(&sb, " ");
+ if (opts->short_name) {
+ strbuf_addf(&sb, "-%c", opts->short_name);
+ }
+ if (opts->long_name) {
+ strbuf_addf(&sb, opts->short_name ? ", --%s" : "--%s",
+ opts->long_name);
+ }
+ switch (opts->type) {
+ case OPTION_INTEGER:
+ strbuf_addstr(&sb, " <n>");
+ break;
+ case OPTION_STRING:
+ if (opts->argh) {
+ strbuf_addf(&sb, " <%s>", opts->argh);
+ } else {
+ strbuf_addstr(&sb, " ...");
+ }
+ break;
+ default:
+ break;
+ }
+ if (sb.len - pos <= USAGE_OPTS_WIDTH) {
+ int pad = USAGE_OPTS_WIDTH - (sb.len - pos) + USAGE_GAP;
+ strbuf_addf(&sb, "%*s%s\n", pad, "", opts->help);
+ } else {
+ strbuf_addf(&sb, "\n%*s%s\n", USAGE_OPTS_WIDTH + USAGE_GAP, "",
+ opts->help);
+ }
+ }
+ usage(sb.buf);
+}
diff --git a/parse-options.h b/parse-options.h
new file mode 100644
index 0000000..4b33d17
--- /dev/null
+++ b/parse-options.h
@@ -0,0 +1,37 @@
+#ifndef PARSE_OPTIONS_H
+#define PARSE_OPTIONS_H
+
+enum option_type {
+ OPTION_BOOLEAN,
+ OPTION_STRING,
+ OPTION_INTEGER,
+ OPTION_GROUP,
+};
+
+struct option {
+ enum option_type type;
+ int short_name;
+ const char *long_name;
+ void *value;
+ const char *argh;
+ const char *help;
+};
+
+#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_GROUP(h) { OPTION_GROUP, 0, NULL, NULL, NULL, (h) }
+
+#define OPT_COPY_DASHDASH 1
+
+/* parse_options() will filter out the processed options and leave the
+ * non-option argments in argv[].
+ * Returns the number of arguments left in argv[].
+ */
+extern int parse_options(int argc, const char **argv,
+ struct option *options, int count,
+ const char * const usagestr[], int flags);
+
+extern NORETURN void make_usage(const char * const usagestr[],
+ struct option *options, int cnt);
+#endif
--
1.5.3.GIT
-
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