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// MIT License
//
// Copyright (c) 2020 Tyge Løvset, NORCE, www.norceresearch.no
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.
// Inspired by https://attractivechaos.wordpress.com/2018/08/31/a-survey-of-argument-parsing-libraries-in-c-c
// Fixed major bugs with option arguments (both long and short), and shows a useful demo of the features.
// Has a more consistent API, written in C99.
#ifndef CGETOPT__H__
#define CGETOPT__H__
#include <string.h>
#include <stdbool.h>
enum {
copt_no_argument = 0,
copt_required_argument = 1,
copt_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
int _i, _pos, _nargs;
} copt_t;
struct copt_option {
char *name;
int has_arg;
int val;
};
static const copt_t copt_init = {1, 0, 0, -1, 1, 0, 0};
static void _copt_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. opt->arg points to the option
// argument if present. The function returns -1 when all command-line arguments
// are parsed. In this case, opt->ind is the index of the first non-option
// argument.
//
// @param opt output; must be initialized to copt_init on first call
// @param permute true: move options ahead of non-option arguments
// @return ASCII val for a short option; longopt.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 copt_getopt(copt_t *opt, int argc, char *argv[],
const char *shortopts, const struct copt_option *longopts,
bool permute) {
int optc = -1, i0, j;
if (permute) {
while (opt->_i < argc && (argv[opt->_i][0] != '-' || argv[opt->_i][1] == '\0'))
++opt->_i, ++opt->_nargs;
}
opt->arg = 0, opt->longidx = -1, i0 = opt->_i;
if (opt->_i >= argc || argv[opt->_i][0] != '-' || argv[opt->_i][1] == '\0') {
opt->ind = opt->_i - opt->_nargs;
return -1;
}
if (argv[opt->_i][0] == '-' && argv[opt->_i][1] == '-') { // "--" or a long option
if (argv[opt->_i][2] == '\0') { // a bare "--"
_copt_permute(argv, opt->_i, opt->_nargs);
++opt->_i, opt->ind = opt->_i - opt->_nargs;
return -1;
}
opt->opt = 0, optc = '?', opt->_pos = -1;
if (longopts) { // parse long options
int k, n_exact = 0, n_partial = 0;
const struct copt_option *o = 0, *o_exact = 0, *o_partial = 0;
for (j = 2; argv[opt->_i][j] != '\0' && argv[opt->_i][j] != '='; ++j) {} // find the end of the option name
for (k = 0; longopts[k].name != 0; ++k)
if (strncmp(&argv[opt->_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) {
opt->opt = optc = o->val, opt->longidx = o - longopts;
if (o->has_arg != copt_no_argument) {
if (argv[opt->_i][j] == '=')
opt->arg = &argv[opt->_i][j + 1];
else if (argv[opt->_i][j] == '\0' && opt->_i < argc - 1 && argv[opt->_i + 1][0] != '-')
opt->arg = argv[++opt->_i];
else if (o->has_arg == copt_required_argument)
optc = ':'; // missing option argument
}
}
}
} else { // a short option
const char *p;
if (opt->_pos == 0) opt->_pos = 1;
optc = opt->opt = argv[opt->_i][opt->_pos++];
p = strchr((char *) shortopts, optc);
if (p == 0) {
optc = '?'; // unknown option
} else if (p[1] == ':') {
if (argv[opt->_i][opt->_pos] != '\0')
opt->arg = &argv[opt->_i][opt->_pos];
else if (opt->_i < argc - 1 && argv[opt->_i + 1][0] != '-')
opt->arg = argv[++opt->_i];
else if (p[2] != ':')
optc = ':';
opt->_pos = -1;
}
}
if (opt->_pos < 0 || argv[opt->_i][opt->_pos] == 0) {
++opt->_i, opt->_pos = 0;
if (opt->_nargs > 0) // permute
for (j = i0; j < opt->_i; ++j)
_copt_permute(argv, j, opt->_nargs);
}
opt->ind = opt->_i - opt->_nargs;
return optc;
}
/* // demo:
int main(int argc, char *argv[])
{
static struct copt_option longopts[] = {
{"foo", copt_no_argument, 'f'},
{"bar", copt_required_argument, 'b'},
{"opt", copt_optional_argument, 'o'},
{NULL}
};
const char* optstr = "ab:c::";
printf("program -a -b ARG -c [ARG] --foo --bar ARG --opt [ARG] [ARGUMENTS]\n");
int c;
copt_t opt = copt_init;
while ((c = copt_getopt(&opt, argc, argv, optstr, longopts, true)) != -1) {
if (c == '?')
opt.longidx == -1 ? printf("unknown option: -%c\n", opt.opt)
: printf("unknown option: %s\n", argv[opt.ind - 1]);
else if (c == ':')
opt.longidx == -1 ? printf("missing argument for -%c\n", opt.opt)
: printf("missing argument for %s\n", argv[opt.ind - 1]);
else
printf("option: %c %s\n", c, opt.arg ? opt.arg : "");
}
printf("\nNon-option arguments:");
for (int i = opt.ind; i < argc; ++i)
printf(" %s", argv[i]);
putchar('\n');
return 0;
}
*/
#endif
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