include/optutils.h

   1 /*
   2  * No copyright is claimed.  This code is in the public domain; do with
   3  * it what you wish.
   4  */
   5 #ifndef UTIL_LINUX_OPTUTILS_H
   6 #define UTIL_LINUX_OPTUTILS_H
   7
   8 #include <assert.h>
   9
  10 #include "c.h"
  11 #include "nls.h"
  12 #include "cctype.h"
  13
  14 static inline const char *option_to_longopt(int c, const struct option *opts)
  15 {
  16         const struct option *o;
  17
  18         assert(!(opts == NULL));
  19         for (o = opts; o->name; o++)
  20                 if (o->val == c)
  21                         return o->name;
  22         return NULL;
  23 }
  24
  25 #ifndef OPTUTILS_EXIT_CODE
  26 # define OPTUTILS_EXIT_CODE EXIT_FAILURE
  27 #endif
  28
  29 /*
  30  * Check collisions between options.
  31  *
  32  * The conflicts between options are described in ul_excl_t array. The
  33  * array contains groups of mutually exclusive options. For example
  34  *
  35  *      static const ul_excl_t excl[] = {
  36  *              { 'Z','b','c' },                // first group
  37  *              { 'b','x' },                    // second group
  38  *              { 0 }
  39  *      };
  40  *
  41  *      int excl_st[ARRAY_SIZE(excl)] = UL_EXCL_STATUS_INIT;
  42  *
  43  *      while ((c = getopt_long(argc, argv, "Zbcx", longopts, NULL)) != -1) {
  44  *
  45  *              err_exclusive_options(c, longopts, excl, excl_st);
  46  *
  47  *              switch (c) {
  48  *              case 'Z':
  49  *                 ....
  50  *              }
  51  *      }
  52  *
  53  * The array excl[] defines two groups of the mutually exclusive options. The
  54  * option '-b' is in the both groups.
  55  *
  56  * Note that the options in the group have to be in ASCII order (ABC..abc..) and
  57  * groups have to be also in ASCII order.
  58  *
  59  * The maximal number of the options in the group is 15 (size of the array is
  60  * 16, last is zero).
  61  *
  62  * The current status of options is stored in excl_st array. The size of the array
  63  * must be the same as number of the groups in the ul_excl_t array.
  64  *
  65  * If you're unsure then see sys-utils/mount.c or misc-utils/findmnt.c.
  66  */
  67 #define UL_EXCL_STATUS_INIT     { 0 }
  68 typedef int ul_excl_t[16];
  69
  70 static inline void err_exclusive_options(
  71                         int c,
  72                         const struct option *opts,
  73                         const ul_excl_t *excl,
  74                         int *status)
  75 {
  76         int e;
  77
  78         for (e = 0; excl[e][0] && excl[e][0] <= c; e++) {
  79                 const int *op = excl[e];
  80
  81                 for (; *op && *op <= c; op++) {
  82                         if (*op != c)
  83                                 continue;
  84                         if (status[e] == 0)
  85                                 status[e] = c;
  86                         else if (status[e] != c) {
  87                                 size_t ct = 0;
  88
  89                                 fprintf(stderr, _("%s: mutually exclusive "
  90                                                   "arguments:"),
  91                                                 program_invocation_short_name);
  92
  93                                 for (op = excl[e];
  94                                      ct + 1 < ARRAY_SIZE(excl[0]) && *op;
  95                                      op++, ct++) {
  96                                         const char *n = option_to_longopt(*op, opts);
  97                                         if (n)
  98                                                 fprintf(stderr, " --%s", n);
  99                                         else if (c_isgraph(*op))
 100                                                 fprintf(stderr, " -%c", *op);
 101                                 }
 102                                 fputc('\n', stderr);
 103                                 exit(OPTUTILS_EXIT_CODE);
 104                         }
 105                         break;
 106                 }
 107         }
 108 }
 109
 110 #endif
 111