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 (void); 28 29char * 30tmpnam (char *s) 31{ 32 int pid = getpid (); 33 34 if (s == NULL) 35 s = tmpnam_buffer; 36 37 /* Generate the filename and make sure that there isn't one called 38 it already. */ 39 40 while (1) 41 { 42 FILE *f; 43 sprintf (s, "%s/%s%x.%x", P_tmpdir, "t", pid, tmpnam_counter); 44 f = fopen (s, "r"); 45 if (f == NULL) 46 break; 47 tmpnam_counter++; 48 fclose (f); 49 } 50 51 return s; 52} 53