How can I get the temporary filename by using the tmpfile ()

Question

tmpfile () functions says that:

The temporary file created is automatically deleted when the stream is closed (fclose) or when the program terminates normally. If the program terminates abnormally, whether the file is deleted depends on the specific system and library implementation."

tmpfile () function returns a stream pointer to the temporary file created and not the path of file. I need temporary filename path as it needed to pass other library function.

My application can exit abnormally so tmpfile () function can work here on abnormal exit.

How can I get the temporary file path and file automatically delete on exit

If you need a file name then there is no point in using tmpfile() — marom, Mar 09 '16 at 11:08
Are you targeting a specific system (e.g. Linux or POSIX) or do you need it to be portable? — jotik, Mar 09 '16 at 11:13
What about using [`mktemp()`](http://linux.die.net/man/3/mktemp) instead? — πάντα ῥεῖ, Mar 09 '16 at 11:15
Some useful answers here : http://stackoverflow.com/questions/1022487/how-to-create-a-temporary-text-file-in-c — vcp, Mar 09 '16 at 11:15
How about creating your own RAII `tempfile` class that automatically deletes the file it points to when it's destroyed? — Simon Kraemer, Mar 09 '16 at 11:45

score 1 · Answer 1 · edited Mar 29 '22 at 11:54

Instead of using tmpfile(), you could use tmpnam().

It will return a filename that can be used to create a temporary file.

See the following example (extracted from http://www.cplusplus.com/reference/cstdio/tmpnam/) :

#include <stdio.h>

int main ()
{
   char buffer [L_tmpnam];
   char *pointer;

   tmpnam (buffer);
   printf ("Tempname #1: %s\n", buffer);

   pointer = tmpnam (NULL);
   printf ("Tempname #2: %s\n", pointer);

   return 0;  
}

You can then use this filename to create your file and delete it upon exit.

Edit:

The name return by tmpnam doesn't specify any path. The default path used by fopen will be your current working directory.
It is up to you to delete the file. It will not be done automatically. You can do it by calling remove.

How can I get the temporary file path and file automatically delete on exit — , Mar 09 '16 at 13:41
@hafiz: you probably want [atexit](http://man7.org/linux/man-pages/man3/atexit.3.html). — Caleb Gray, Oct 17 '16 at 12:43

How can I get the temporary filename by using the tmpfile ()

1 Answers1