klib/ketopt.h

121 lines
3.9 KiB
C

#ifndef KETOPT_H
#define KETOPT_H
#include <string.h> /* for strchr() and strncmp() */
#define ko_no_argument 0
#define ko_required_argument 1
#define ko_optional_argument 2
typedef struct {
int ind; /* equivalent to optind */
int opt; /* equivalent to optopt */
char *arg; /* equivalent to optarg */
int longidx; /* index of a long option; or -1 if short */
/* private variables not intended for external uses */
int i, pos, n_args;
} ketopt_t;
typedef struct {
char *name;
int has_arg;
int val;
} ko_longopt_t;
static ketopt_t KETOPT_INIT = { 1, 0, 0, -1, 1, 0, 0 };
static void ketopt_permute(char *argv[], int j, int n) /* move argv[j] over n elements to the left */
{
int k;
char *p = argv[j];
for (k = 0; k < n; ++k)
argv[j - k] = argv[j - k - 1];
argv[j - k] = p;
}
/**
* Parse command-line options and arguments
*
* This fuction has a similar interface to GNU's getopt_long(). Each call
* parses one option and returns the option name. s->arg points to the option
* argument if present. The function returns -1 when all command-line arguments
* are parsed. In this case, s->ind is the index of the first non-option
* argument.
*
* @param s status; shall be initialized to KETOPT_INIT on the first call
* @param argc length of argv[]
* @param argv list of command-line arguments; argv[0] is ignored
* @param permute non-zero to move options ahead of non-option arguments
* @param ostr option string
* @param longopts long options
*
* @return ASCII for a short option; ko_longopt_t::val for a long option; -1 if
* argv[] is fully processed; '?' for an unknown option or an ambiguous
* long option; ':' if an option argument is missing
*/
static int ketopt(ketopt_t *s, int argc, char *argv[], int permute, const char *ostr, const ko_longopt_t *longopts)
{
int opt = -1, i0, j;
if (permute) {
while (s->i < argc && (argv[s->i][0] != '-' || argv[s->i][1] == '\0'))
++s->i, ++s->n_args;
}
s->arg = 0, s->longidx = -1, i0 = s->i;
if (s->i >= argc || argv[s->i][0] != '-' || argv[s->i][1] == '\0') {
s->ind = s->i - s->n_args;
return -1;
}
if (argv[s->i][0] == '-' && argv[s->i][1] == '-') { /* "--" or a long option */
if (argv[s->i][2] == '\0') { /* a bare "--" */
ketopt_permute(argv, s->i, s->n_args);
++s->i, s->ind = s->i - s->n_args;
return -1;
}
s->opt = 0, opt = '?', s->pos = -1;
if (longopts) { /* parse long options */
int k, n_exact = 0, n_partial = 0;
const ko_longopt_t *o = 0, *o_exact = 0, *o_partial = 0;
for (j = 2; argv[s->i][j] != '\0' && argv[s->i][j] != '='; ++j) {} /* find the end of the option name */
for (k = 0; longopts[k].name != 0; ++k)
if (strncmp(&argv[s->i][2], longopts[k].name, j - 2) == 0) {
if (longopts[k].name[j - 2] == 0) ++n_exact, o_exact = &longopts[k];
else ++n_partial, o_partial = &longopts[k];
}
if (n_exact > 1 || (n_exact == 0 && n_partial > 1)) return '?';
o = n_exact == 1? o_exact : n_partial == 1? o_partial : 0;
if (o) {
s->opt = opt = o->val, s->longidx = o - longopts;
if (argv[s->i][j] == '=') s->arg = &argv[s->i][j + 1];
if (o->has_arg == 1 && argv[s->i][j] == '\0') {
if (s->i < argc - 1) s->arg = argv[++s->i];
else opt = ':'; /* missing option argument */
}
}
}
} else { /* a short option */
const char *p;
if (s->pos == 0) s->pos = 1;
opt = s->opt = argv[s->i][s->pos++];
p = strchr((char*)ostr, opt);
if (p == 0) {
opt = '?'; /* unknown option */
} else if (p[1] == ':') {
if (argv[s->i][s->pos] == 0) {
if (s->i < argc - 1) s->arg = argv[++s->i];
else opt = ':'; /* missing option argument */
} else s->arg = &argv[s->i][s->pos];
s->pos = -1;
}
}
if (s->pos < 0 || argv[s->i][s->pos] == 0) {
++s->i, s->pos = 0;
if (s->n_args > 0) /* permute */
for (j = i0; j < s->i; ++j)
ketopt_permute(argv, j, s->n_args);
}
s->ind = s->i - s->n_args;
return opt;
}
#endif