getopt.c

   1 /*
   2  * getopt() - command option parsing
   3  *
   4  * Gunnar Ritter, Freiburg i. Br., Germany, March 2002.
   5  */
   6
   7 #include "config.h"
   8
   9 #ifndef USE_BUILTIN_GETOPT
  10 typedef int avoid_empty_file_compiler_warning;
  11 #else
  12
  13 # include <sys/types.h>
  14 # ifdef HAVE_ALLOCA
  15 #  ifdef HAVE_ALLOCA_H
  16 #   include <alloca.h>
  17 #  else
  18 #   include <stdlib.h>
  19 #  endif
  20 # endif
  21 # include <string.h>
  22
  23 # ifdef HAVE_ALLOCA
  24 #  define ac_alloc(n)   alloca(n)
  25 #  define ac_free(n)
  26 # else
  27 extern void *smalloc(size_t);
  28 #  define ac_alloc(n)   smalloc(n)
  29 #  define ac_free(n)    free(n)
  30 # endif
  31
  32 # ifndef HAVE_SSIZE_T
  33 typedef long    ssize_t;
  34 # endif
  35
  36 /*
  37  * One should not think that re-implementing this is necessary, but
  38  *
  39  * - Some libcs print weird messages.
  40  *
  41  * - GNU libc getopt() is totally brain-damaged, as it requires special
  42  *   care _not_ to reorder parameters and can't be told to work correctly
  43  *   with ':' as first optstring character at all.
  44  */
  45
  46 char    *optarg;
  47 int     optind = 1;
  48 int     opterr = 1;
  49 int     optopt;
  50
  51 static void
  52 error(const char *s, int c)
  53 {
  54         /*
  55          * Avoid including <unistd.h>, in case its getopt() declaration
  56          * conflicts.
  57          */
  58         extern ssize_t  write(int, const void *, size_t);
  59         const char      *msg = 0;
  60         char    *buf, *bp;
  61
  62         switch (c) {
  63         case '?':
  64                 msg = ": illegal option -- ";
  65                 break;
  66         case ':':
  67                 msg = ": option requires an argument -- ";
  68                 break;
  69         }
  70         bp = buf = ac_alloc(strlen(s) + strlen(msg) + 2);
  71         while (*s)
  72                 *bp++ = *s++;
  73         while (*msg)
  74                 *bp++ = *msg++;
  75         *bp++ = optopt;
  76         *bp++ = '\n';
  77         write(2, buf, bp - buf);
  78         ac_free(buf);
  79 }
  80
  81 int
  82 getopt(int argc, char *const argv[], const char *optstring)
  83 {
  84         int     colon;
  85         static const char       *lastp;
  86         const char      *curp;
  87
  88         if (optstring[0] == ':') {
  89                 colon = 1;
  90                 optstring++;
  91         } else
  92                 colon = 0;
  93         if (lastp) {
  94                 curp = lastp;
  95                 lastp = 0;
  96         } else {
  97                 if (optind >= argc || argv[optind] == 0 ||
  98                                 argv[optind][0] != '-' ||
  99                                 argv[optind][1] == '\0')
 100                         return -1;
 101                 if (argv[optind][1] == '-' && argv[optind][2] == '\0') {
 102                         optind++;
 103                         return -1;
 104                 }
 105                 curp = &argv[optind][1];
 106         }
 107         optopt = curp[0] & 0377;
 108         while (optstring[0]) {
 109                 if (optstring[0] == ':') {
 110                         optstring++;
 111                         continue;
 112                 }
 113                 if ((optstring[0] & 0377) == optopt) {
 114                         if (optstring[1] == ':') {
 115                                 if (curp[1] != '\0') {
 116                                         optarg = (char *)&curp[1];
 117                                         optind++;
 118                                 } else {
 119                                         if ((optind += 2) > argc) {
 120                                                 if (!colon && opterr)
 121                                                         error(argv[0], ':');
 122                                                 return colon ? ':' : '?';
 123                                         }
 124                                         optarg = argv[optind - 1];
 125                                 }
 126                         } else {
 127                                 if (curp[1] != '\0')
 128                                         lastp = &curp[1];
 129                                 else
 130                                         optind++;
 131                                 optarg = 0;
 132                         }
 133                         return optopt;
 134                 }
 135                 optstring++;
 136         }
 137         if (!colon && opterr)
 138                 error(argv[0], '?');
 139         if (curp[1] != '\0')
 140                 lastp = &curp[1];
 141         else
 142                 optind++;
 143         optarg = 0;
 144         return '?';
 145 }
 146
 147 # ifdef __APPLE__
 148 /*
 149  * Starting with Mac OS 10.5 Leopard, <unistd.h> turns getopt()
 150  * into getopt$UNIX2003() by default. Consequently, this function
 151  * is called instead of the one defined above. However, optind is
 152  * still taken from this file, so in effect, options are not
 153  * properly handled. Defining an own getopt$UNIX2003() function
 154  * works around this issue.
 155  */
 156 int
 157 getopt$UNIX2003(int argc, char *const argv[], const char *optstring)
 158 {
 159         return getopt(argc, argv, optstring);
 160 }
 161 # endif /* __APPLE__ */
 162 #endif /* USE_BUILTIN_GETOPT */