mkstemp.c

   1 #include <fcntl.h>
   2 #include <string.h>
   3
   4 static int tmpid;
   5 static char *digs = "0123456789abcdef";
   6
   7 int mkstemp(char *t)
   8 {
   9         char *x = t + strlen(t) - 6;
  10         int fd;
  11         int i;
  12         if (strlen(t) < 6)
  13                 return -1;
  14         for (i = 0; i < 6; i++)
  15                 x[i] = '0';
  16         while ((fd = open(t, O_RDWR | O_EXCL | O_CREAT, 0600)) == -1) {
  17                 int n = ++tmpid;
  18                 for (i = 0; i < 6; i++) {
  19                         x[5 - i] = digs[n & 0x0f];
  20                         n <<= 4;
  21                 }
  22         }
  23         unlink(t);
  24         return fd;
  25 }