tmpfile(3) - Linux man page

Name

tmpfile - create a temporary file

Synopsis

#include <stdio.h>
FILE *tmpfile(void);

Description

The tmpfile() function opens a unique temporary file in binary read/write (w+b) mode. The file will be automatically deleted when it is closed or the program terminates.

Return Value

The tmpfile() function returns a stream descriptor, or NULL if a unique filename cannot be generated or the unique file cannot be opened. In the latter case, errno is set to indicate the error.

Errors

EACCES: Search permission denied for directory in file's path prefix.
EEXIST: Unable to generate a unique filename.
EINTR: The call was interrupted by a signal.
EMFILE: Too many file descriptors in use by the process.
ENFILE: Too many files open in the system.
ENOSPC: There was no room in the directory to add the new filename.
EROFS: Read-only file system.

Conforming to

SVr4, 4.3BSD, C89, C99, SUSv2, POSIX.1-2001.

Notes

POSIX.1-2001 specifies: an error message may be written to stdout if the stream cannot be opened.

The standard does not specify the directory that tmpfile() will use. Glibc will try the path prefix P_tmpdir defined in <stdio.h>, and if that fails the directory /tmp.

Referenced By

exit(2), explain(1), explain(3), explain_tmpfile(3), explain_tmpfile_or_die(3), getpid(2), mkdtemp(3)