libc/stdlib/mkstemp.c

   1 /*
   2  *  ZeX/OS
   3  *  Copyright (C) 2009  Tomas 'ZeXx86' Jedrzejek (zexx86@zexos.org)
   4  *
   5  *  This program is free software: you can redistribute it and/or modify
   6  *  it under the terms of the GNU General Public License as published by
   7  *  the Free Software Foundation, either version 3 of the License, or
   8  *  (at your option) any later version.
   9  *
  10  *  This program is distributed in the hope that it will be useful,
  11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  *  GNU General Public License for more details.
  14  *
  15  *  You should have received a copy of the GNU General Public License
  16  *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19
  20 #include <time.h>
  21 #include <fcntl.h>
  22 #include <errno.h>
  23 #include <stdio.h>
  24 #include <stdlib.h>
  25 #include <string.h>
  26
  27 int mkstemp (char *tmplate)
  28 {
  29         static const char letters[] = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
  30         int len, r;
  31         char *c;
  32
  33         errno = 0;
  34
  35         len = strlen (tmplate);
  36
  37         if (len >= 6) {
  38                 c = tmplate + len - 6;
  39                 srand((unsigned int) time (0));
  40
  41                 if (strncmp (c, "XXXXXX", 6) == 0) {
  42                         int iChr;
  43                         for (iChr = 0; iChr < 6; iChr ++) {
  44                                 r = rand() / 528.5;
  45                                 *(c ++) = letters[r > 0 ? r - 1 : 0];
  46                         }
  47                 } else {
  48                         errno = EINVAL;
  49                         return -1;
  50                 }
  51         } else {
  52                 errno = EINVAL;
  53                 return -1;
  54         }
  55
  56         return open (tmplate, O_CREAT | O_RDWR);
  57 }