simplify getopt_long argv permutation loop logic
[musl] / src / misc / getopt_long.c
1 #define _GNU_SOURCE
2 #include <stddef.h>
3 #include <getopt.h>
4 #include <stdio.h>
5
6 extern int __optpos, __optreset;
7
8 static void permute(char *const *argv, int dest, int src)
9 {
10         char **av = (char **)argv;
11         char *tmp = av[src];
12         int i;
13         for (i=src; i>dest; i--)
14                 av[i] = av[i-1];
15         av[dest] = tmp;
16 }
17
18 static int __getopt_long_core(int argc, char *const *argv, const char *optstring, const struct option *longopts, int *idx, int longonly);
19
20 static int __getopt_long(int argc, char *const *argv, const char *optstring, const struct option *longopts, int *idx, int longonly)
21 {
22         int ret, skipped, resumed;
23         if (!optind || __optreset) {
24                 __optreset = 0;
25                 __optpos = 0;
26                 optind = 1;
27         }
28         if (optind >= argc || !argv[optind]) return -1;
29         skipped = optind;
30         if (optstring[0] != '+' && optstring[0] != '-') {
31                 int i;
32                 for (i=optind; ; i++) {
33                         if (i >= argc || !argv[i]) return -1;
34                         if (argv[i][0] == '-' && argv[i][1]) break;
35                 }
36                 optind = i;
37         }
38         resumed = optind;
39         ret = __getopt_long_core(argc, argv, optstring, longopts, idx, longonly);
40         if (resumed > skipped) {
41                 int i, cnt = optind-resumed;
42                 for (i=0; i<cnt; i++)
43                         permute(argv, skipped, optind-1);
44                 optind = skipped + cnt;
45         }
46         return ret;
47 }
48
49 static int __getopt_long_core(int argc, char *const *argv, const char *optstring, const struct option *longopts, int *idx, int longonly)
50 {
51
52         if (longopts && argv[optind][0] == '-' &&
53                 ((longonly && argv[optind][1]) ||
54                  (argv[optind][1] == '-' && argv[optind][2])))
55         {
56                 int i, cnt, match;
57                 char *opt;
58                 for (cnt=i=0; longopts[i].name; i++) {
59                         const char *name = longopts[i].name;
60                         opt = argv[optind]+1;
61                         if (*opt == '-') opt++;
62                         for (; *name && *name == *opt; name++, opt++);
63                         if (*opt && *opt != '=') continue;
64                         match = i;
65                         if (!*name) {
66                                 cnt = 1;
67                                 break;
68                         }
69                         cnt++;
70                 }
71                 if (cnt==1) {
72                         i = match;
73                         optind++;
74                         if (*opt == '=') {
75                                 if (!longopts[i].has_arg) return '?';
76                                 optarg = opt+1;
77                         } else {
78                                 if (longopts[i].has_arg == required_argument) {
79                                         if (!(optarg = argv[optind]))
80                                                 return ':';
81                                         optind++;
82                                 } else optarg = NULL;
83                         }
84                         if (idx) *idx = i;
85                         if (longopts[i].flag) {
86                                 *longopts[i].flag = longopts[i].val;
87                                 return 0;
88                         }
89                         return longopts[i].val;
90                 }
91                 if (argv[optind][1] == '-') {
92                         optind++;
93                         return '?';
94                 }
95         }
96         return getopt(argc, argv, optstring);
97 }
98
99 int getopt_long(int argc, char *const *argv, const char *optstring, const struct option *longopts, int *idx)
100 {
101         return __getopt_long(argc, argv, optstring, longopts, idx, 0);
102 }
103
104 int getopt_long_only(int argc, char *const *argv, const char *optstring, const struct option *longopts, int *idx)
105 {
106         return __getopt_long(argc, argv, optstring, longopts, idx, 1);
107 }