ssh-groupcommand/libstrtokdup.c

   1
   2 #include <string.h>
   3 #include <stdio.h>
   4 #include <ctype.h>
   5
   6 #include "libmallocab.h"
   7
   8 #define DEBUG_LIBSTRTOKDUP 0
   9
  10 /*
  11    Return a pointer to a copy of n-th word of a string.
  12    Return NULL if there are not enough words.
  13    Count starts at 1.
  14    Words are separated by whitespace
  15    Caller is responsible to free() the returning pointer.
  16  */
  17
  18 char* strtokdup(const char* s, unsigned int nth)
  19 {
  20         char* r;
  21         unsigned int i, L;
  22
  23         #if DEBUG_LIBSTRTOKDUP
  24         fprintf(stderr, "strtokdup('%s', %d)\n", s, nth);
  25         #endif
  26         if(s == NULL)
  27                 return NULL;
  28
  29         i = 0;
  30         /* Jump to nth token */
  31         while(nth > 0)
  32         {
  33                 /* Strip leading whitespace */
  34                 while(isspace(s[i]) && s[i] != '\0') i++;
  35                 if(s[i] == '\0')
  36                         return NULL;
  37                 if(nth > 1)
  38                 {
  39                         /* Skip to next whitespace */
  40                         while(!isspace(s[i]) && s[i] != '\0') i++;
  41                         if(s[i] == '\0')
  42                                 return NULL;
  43                 }
  44                 nth--;
  45         }
  46
  47         L = strcspn(s+i, " \f\n\r\t\v");
  48         r = mallocab(L+1);
  49         strncpy(r, s+i, L);
  50         r[L] = '\0';
  51         #if DEBUG_LIBSTRTOKDUP
  52         fprintf(stderr, " -> '%s'\n", r);
  53         #endif
  54         return r;
  55 }