1 /* $OpenBSD: getopt.c,v 1.1 1999/10/01 01:08:29 angelos Exp $ */
2 
3 #include "config.h"
4 
5 #include <stdio.h>
6 #include <ctype.h>
7 #include <string.h>
8 
9 /*** getopt
10  *
11  *   This function is the public domain version of getopt, the command
12  *   line argument processor, and hence is NOT copyrighted by Microsoft,
13  *   IBM, or AT&T.
14  */
15 
16 #define ERR(s, c)   if(opterr){\
17    (void) fputs(argv[0], stderr);\
18    (void) fputs(s, stderr);\
19    (void) fputc(c, stderr);\
20    (void) fputc('\n', stderr);}
21 
22 int   opterr = 1;   /* flag:error message on unrecognzed options */
23 int   optind = 1;   /* last touched cmdline argument */
24 int   optopt;       /* last returned option */
25 char  *optarg;      /* argument to optopt */
26 
27 /* int    argc is the number of arguments on cmdline */
28 /* char   **argv is the pointer to array of cmdline arguments */
29 /* char   *opts is the string of all valid options   */
30 /* each char case must be given; options taking an arg are followed by =
31 ':' */
getopt(int argc,char * const * argv,const char * opts)32 int getopt(int argc, char * const *argv, const char *opts)
33 {
34    static int sp = 1;
35    register int c;
36    register char *cp;
37    if(sp == 1) {
38       /* check for end of options */
39       if(optind >= argc ||
40           (argv[optind][0] != '/' &&
41           argv[optind][0] != '-') ||
42           argv[optind][1] == '\0')
43          return(EOF);
44       else if(!strcmp(argv[optind], "--")) {
45          optind++;
46          return(EOF);
47       }
48    }
49    optopt = c = argv[optind][sp];
50    if(c == ':' || (cp=strchr(opts, c)) == NULL) {
51       /* if arg sentinel as option or other invalid option,
52          handle the error and return '?' */
53       ERR(": illegal option -- ", (char)c);
54       if(argv[optind][++sp] == '\0') {
55          optind++;
56          sp = 1;
57       }
58       return('?');
59    }
60    if(*++cp == ':') {
61       /* if option is given an argument...  */
62       if(argv[optind][sp+1] != '\0')
63          /* and the OptArg is in that CmdLineArg, return it... */
64          optarg = &argv[optind++][sp+1];
65       else if(++optind >= argc) {
66          /* but if the OptArg isn't there and the next CmdLineArg
67             isn't either, handle the error... */
68          ERR(": option requires an argument -- ", (char)c);
69          sp = 1;
70          return('?');
71       } else
72          /* but if there is another CmdLineArg there, return that */
73          optarg = argv[optind++];
74       /* and set up for the next CmdLineArg */
75       sp = 1;
76    } else {
77       /* no arg for this opt, so null arg and set up for next option */
78       if(argv[optind][++sp] == '\0') {
79          sp = 1;
80          optind++;
81       }
82       optarg = NULL;
83    }
84    return(c);
85 }
86