lib/stdio/tmpnam.c

   1 /*
   2  * tmpnam.c - create a unique filename
   3  */
   4 /* $Header$ */
   5
   6 #if     defined(_POSIX_SOURCE)
   7 #include        <sys/types.h>
   8 #endif
   9 #include        <stdio.h>
  10 #include        <string.h>
  11 #include        "loc_incl.h"
  12
  13 pid_t _getpid(void);
  14
  15 char *
  16 tmpnam(char *s) {
  17         static char name_buffer[L_tmpnam] = "/tmp/tmp.";
  18         static unsigned long count = 0;
  19         static char *name = NULL;
  20
  21         if (!name) {
  22                 name = name_buffer + strlen(name_buffer);
  23                 name = _i_compute((unsigned long)_getpid(), 10, name, 5);
  24                 *name++ = '.';
  25                 *name = '\0';
  26         }
  27         if (++count > TMP_MAX) count = 1;       /* wrap-around */
  28         *_i_compute(count, 10, name, 3) = '\0';
  29         if (s) return strcpy(s, name_buffer);
  30         else return name_buffer;
  31 }