| 1 | /* |
| 2 | |
| 3 | @deftypefn Supplemental char* tmpnam (char *@var{s}) |
| 4 | |
| 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. |
| 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 | |
| 24 | static char tmpnam_buffer[L_tmpnam]; |
| 25 | static int tmpnam_counter; |
| 26 | |
| 27 | extern int getpid (void); |
| 28 | |
| 29 | char * |
| 30 | tmpnam (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 | } |