lib/roken/mkstemp.c

   1 /*
   2  * Copyright (c) 1995, 1996, 1997 Kungliga Tekniska Högskolan
   3  * (Royal Institute of Technology, Stockholm, Sweden).
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  *
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  *
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  *
  17  * 3. Neither the name of the Institute nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #include <config.h>
  35
  36 #include <string.h>
  37 #ifdef HAVE_UNISTD_H
  38 #include <unistd.h>
  39 #endif
  40 #ifdef HAVE_FCNTL_H
  41 #include <fcntl.h>
  42 #endif
  43 #include <errno.h>
  44
  45 #include <roken.h>
  46
  47 #ifndef HAVE_MKSTEMP
  48
  49 ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL
  50 mkstemp(char *template)
  51 {
  52     int start, i;
  53     pid_t val;
  54     val = getpid();
  55     start = strlen(template) - 1;
  56     while(template[start] == 'X') {
  57         template[start] = '0' + val % 10;
  58         val /= 10;
  59         start--;
  60     }
  61
  62     do{
  63         int fd;
  64         fd = open(template, O_RDWR | O_CREAT | O_EXCL, 0600);
  65         if(fd >= 0 || errno != EEXIST)
  66             return fd;
  67         i = start + 1;
  68         do{
  69             if(template[i] == 0)
  70                 return -1;
  71             template[i]++;
  72             if(template[i] == '9' + 1)
  73                 template[i] = 'a';
  74             if(template[i] <= 'z')
  75                 break;
  76             template[i] = 'a';
  77             i++;
  78         }while(1);
  79     }while(1);
  80 }
  81
  82 #endif