path: root/mkdtemp.c

/* taken from XFCE's Xarchiver, made to work without glib for mutt */

#include <sys/stat.h>
#include <unistd.h>
#include <errno.h>
#include <time.h>
#include <string.h>

/* mkdtemp function for systems which don't have one */
char *mkdtemp (char *tmpl)
{
  static const char LETTERS[] = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
  static unsigned long value = 0;
  unsigned long     v;
  int               len;
  int               i, j;

  len = strlen (tmpl);
  if (len < 6 || strcmp (&tmpl[len - 6], "XXXXXX") != 0)
  {
    errno = EINVAL;
    return NULL;
  }

  value += ((unsigned long) time (NULL)) ^ getpid ();

  for (i = 0; i < 7 ; ++i, value += 7777)
  {
    /* fill in the random bits */
    for (j = 0, v = value; j < 6; ++j)
    {
      tmpl[(len - 6) + j] = LETTERS[v % 62];
      v /= 62;
    }

    /* try to create the directory */
    if (mkdir (tmpl, 0700) == 0)
      return tmpl;
    else if (errno != EEXIST)
      return NULL;
  }

  errno = EEXIST;
  return NULL;
}