mkstemp.c

   1 #include <fcntl.h>
   2 #include <string.h>
   3 #include <unistd.h>
   4
   5 static int tmpid;
   6 static char *digs = "0123456789abcdef";
   7
   8 int mkstemp(char *t)
   9 {
  10         char *x = t + strlen(t) - 6;
  11         int fd;
  12         int i;
  13         if (strlen(t) < 6)
  14                 return -1;
  15         for (i = 0; i < 6; i++)
  16                 x[i] = '0';
  17         while ((fd = open(t, O_RDWR | O_EXCL | O_CREAT, 0600)) == -1) {
  18                 int n = ++tmpid;
  19                 for (i = 0; i < 6; i++) {
  20                         x[5 - i] = digs[n & 0x0f];
  21                         n <<= 4;
  22                 }
  23         }
  24         unlink(t);
  25         return fd;
  26 }