2018-11-09 Richard Biener <rguenther@suse.de>
[official-gcc.git] / libiberty / tmpnam.c
blobcc343336642f61009e03f8d9592b0d9ae635a9e0
1 /*
3 @deftypefn Supplemental char* tmpnam (char *@var{s})
5 This function attempts to create a name for a temporary file, which
6 will be a valid file name yet not exist when @code{tmpnam} checks for
7 it. @var{s} must point to a buffer of at least @code{L_tmpnam} bytes,
8 or be @code{NULL}. Use of this function creates a security risk, and it must
9 not be used in new projects. Use @code{mkstemp} instead.
11 @end deftypefn
15 #include <stdio.h>
17 #ifndef L_tmpnam
18 #define L_tmpnam 100
19 #endif
20 #ifndef P_tmpdir
21 #define P_tmpdir "/usr/tmp"
22 #endif
24 static char tmpnam_buffer[L_tmpnam];
25 static int tmpnam_counter;
27 extern int getpid (void);
29 char *
30 tmpnam (char *s)
32 int pid = getpid ();
34 if (s == NULL)
35 s = tmpnam_buffer;
37 /* Generate the filename and make sure that there isn't one called
38 it already. */
40 while (1)
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);
51 return s;