/* @deftypefn Supplemental char* tmpnam (char *@var{s}) This function attempts to create a name for a temporary file, whichwill be a valid file name yet not exist when @code{tmpnam} checks forit.  @var{s} must point to a buffer of at least @code{L_tmpnam} bytes,or be @code{NULL}.  Use of this function creates a security risk, and it mustnot be used in new projects.  Use @code{mkstemp} instead. @end deftypefn */ #include <stdio.h> #ifndef L_tmpnam#define L_tmpnam 100#endif#ifndef P_tmpdir#define P_tmpdir "/usr/tmp"#endif static char tmpnam_buffer[L_tmpnam];static int tmpnam_counter; extern int getpid (void); char *tmpnam (char *s){  int pid = getpid ();   if (s == NULL)    s = tmpnam_buffer;   /*  Generate the filename and make sure that there isn't one called      it already.  */   while (1)    {      FILE *f;      sprintf (s, "%s/%s%x.%x", P_tmpdir, "t", pid, tmpnam_counter);      f = fopen (s, "r");      if (f == NULL)	break;      tmpnam_counter++;      fclose (f);    }   return s;}