tmpfile - create a temporary file

       For an explanation of the terms used in this section, see attributes(7).
       ┌─────────────────────────────────────────────────────────────────────────────┬───────────────┬─────────┐
       │ Interface                                                                   │ Attribute     │ Value   │
       ├─────────────────────────────────────────────────────────────────────────────┼───────────────┼─────────┤
       │ tmpfile()                                                                   │ Thread safety │ MT-Safe │
       └─────────────────────────────────────────────────────────────────────────────┴───────────────┴─────────┘

       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.

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; see signal(7).

       EMFILE The per-process limit on the number of open file descriptors has been reached.

       ENFILE The system-wide limit on the total number of open files has been reached.

       ENOSPC There was no room in the directory to add the new filename.

       EROFS  Read-only filesystem.

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

       Standard C library (libc, -lc)

       tmpfile - create a temporary file

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

       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.

exit(3), mkstemp(3), mktemp(3), tempnam(3), tmpnam(3)

Linux man-pages 6.9.1                              2024-05-02                                         tmpfile(3)

       C11, POSIX.1-2008.

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

       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, then the directory /tmp.