1/* 2 3@deftypefn Supplemental char* tmpnam (char *@var{s}) 4 5This function attempts to create a name for a temporary file, which 6will be a valid file name yet not exist when @code{tmpnam} checks for 7it. @var{s} must point to a buffer of at least @code{L_tmpnam} bytes, 8or be @code{NULL}. Use of this function creates a security risk, and it must 9not be used in new projects. Use @code{mkstemp} instead. 10 11@end deftypefn 12 13*/ 14 15#include <stdio.h> 16 17#ifndef L_tmpnam 18#define L_tmpnam 100 19#endif 20#ifndef P_tmpdir 21#define P_tmpdir "/usr/tmp" 22#endif 23 24static char tmpnam_buffer[L_tmpnam]; 25static int tmpnam_counter; 26 27extern int getpid (); 28 29char * 30tmpnam (s) 31 char *s; 32{ 33 int pid = getpid (); 34 35 if (s == NULL) 36 s = tmpnam_buffer; 37 38 /* Generate the filename and make sure that there isn't one called 39 it already. */ 40 41 while (1) 42 { 43 FILE *f; 44 sprintf (s, "%s/%s%x.%x", P_tmpdir, "t", pid, tmpnam_counter); 45 f = fopen (s, "r"); 46 if (f == NULL) 47 break; 48 tmpnam_counter++; 49 fclose (f); 50 } 51 52 return s; 53} 54