git-commit-vandalism/parse-options.c
Alex Riesen f389c808b6 Rework make_usage to print the usage message immediately
Signed-off-by: Alex Riesen <raa.lkml@gmail.com>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2007-10-29 21:03:30 -07:00

228 lines
5.1 KiB
C

#include "git-compat-util.h"
#include "parse-options.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 * const 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_with_options(usagestr, options);
if (parse_short_opt(&args, options) < 0)
usage_with_options(usagestr, options);
} while (args.opt);
continue;
}
if (!arg[2]) { /* "--" */
if (!(flags & PARSE_OPT_KEEP_DASHDASH)) {
args.argc--;
args.argv++;
}
break;
}
if (!strcmp(arg + 2, "help"))
usage_with_options(usagestr, options);
if (parse_long_opt(&args, arg + 2, options))
usage_with_options(usagestr, options);
}
memmove(argv + j, args.argv, args.argc * sizeof(*argv));
argv[j + args.argc] = NULL;
return j + args.argc;
}
#define USAGE_OPTS_WIDTH 24
#define USAGE_GAP 2
void usage_with_options(const char * const *usagestr,
const struct option *opts)
{
fprintf(stderr, "usage: %s\n", *usagestr++);
while (*usagestr && **usagestr)
fprintf(stderr, " or: %s\n", *usagestr++);
while (*usagestr)
fprintf(stderr, " %s\n", *usagestr++);
if (opts->type != OPTION_GROUP)
fputc('\n', stderr);
for (; opts->type != OPTION_END; opts++) {
size_t pos;
int pad;
if (opts->type == OPTION_GROUP) {
fputc('\n', stderr);
if (*opts->help)
fprintf(stderr, "%s\n", opts->help);
continue;
}
pos = fprintf(stderr, " ");
if (opts->short_name)
pos += fprintf(stderr, "-%c", opts->short_name);
if (opts->long_name && opts->short_name)
pos += fprintf(stderr, ", ");
if (opts->long_name)
pos += fprintf(stderr, "--%s", opts->long_name);
switch (opts->type) {
case OPTION_INTEGER:
pos += fprintf(stderr, " <n>");
break;
case OPTION_STRING:
if (opts->argh)
pos += fprintf(stderr, " <%s>", opts->argh);
else
pos += fprintf(stderr, " ...");
break;
default:
break;
}
if (pos <= USAGE_OPTS_WIDTH)
pad = USAGE_OPTS_WIDTH - pos;
else {
fputc('\n', stderr);
pad = USAGE_OPTS_WIDTH;
}
fprintf(stderr, "%*s%s\n", pad + USAGE_GAP, "", opts->help);
}
fputc('\n', stderr);
exit(129);
}