posix man page for tempnam

TEMPNAM(3P)						     POSIX Programmer's Manual						       TEMPNAM(3P)

PROLOG
       This  manual page is part of the POSIX Programmer's Manual.  The Linux implementation of this interface may differ (consult the correspond-
       ing Linux manual page for details of Linux behavior), or the interface may not be implemented on Linux.

NAME
       tempnam -- create a name for a temporary file

SYNOPSIS
       #include <stdio.h>

       char *tempnam(const char *dir, const char *pfx);

DESCRIPTION
       The tempnam() function shall generate a pathname that may be used for a temporary file.

       The tempnam() function allows the user to control the choice of a directory. The dir argument points to the name of the directory in  which
       the file is to be created. If dir is a null pointer or points to a string which is not a name for an appropriate directory, the path prefix
       defined as P_tmpdir in the <stdio.h> header shall be used. If that directory is not accessible, an implementation-defined directory may	be
       used.

       Many applications prefer their temporary files to have certain initial letter sequences in their names. The pfx argument should be used for
       this. This argument may be a null pointer or point to a string of up to five bytes to be used as the beginning of the filename.

       Some implementations of tempnam() may use tmpnam() internally. On such implementations, if called more than {TMP_MAX}  times  in  a  single
       process, the behavior is implementation-defined.

RETURN VALUE
       Upon  successful completion, tempnam() shall allocate space for a string, put the generated pathname in that space, and return a pointer to
       it. The pointer shall be suitable for use in a subsequent call to free().  Otherwise, it shall return a null pointer and set errno to indi-
       cate the error.

ERRORS
       The tempnam() function shall fail if:

       ENOMEM Insufficient storage space is available.

       The following sections are informative.

EXAMPLES
   Generating a Pathname
       The  following example generates a pathname for a temporary file in directory /tmp, with the prefix file.  After the pathname has been cre-
       ated, the call to free() deallocates the space used to store the pathname.

	   #include <stdio.h>
	   #include <stdlib.h>
	   ...
	   const char *directory = "/tmp";
	   const char *fileprefix = "file";
	   char *file;

	   file = tempnam(directory, fileprefix);
	   free(file);

APPLICATION USAGE
       This function only creates pathnames. It is the application's responsibility to create and remove the files. Between the time a pathname is
       created	and the file is opened, it is possible for some other process to create a file with the same name. Applications may find tmpfile()
       more useful.

       Applications should use the tmpfile(), mkdtemp(), or mkstemp() functions instead of the obsolescent tempnam() function.

RATIONALE
       None.

FUTURE DIRECTIONS
       The tempnam() function may be removed in a future version.

SEE ALSO
       fopen(), free(), mkdtemp(), open(), tmpfile(), tmpnam(), unlink()

       The Base Definitions volume of POSIX.1-2008, <stdio.h>

COPYRIGHT
       Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2013 Edition, Standard for Information Technol-
       ogy  --	Portable  Operating  System  Interface (POSIX), The Open Group Base Specifications Issue 7, Copyright (C) 2013 by the Institute of
       Electrical and Electronics Engineers, Inc and The Open Group.  (This is POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) In the
       event of any discrepancy between this version and the original IEEE and The Open Group Standard, the original IEEE and The Open Group Stan-
       dard is the referee document. The original Standard can be obtained online at http://www.unix.org/online.html .

       Any typographical or formatting errors that appear in this page are most likely to have been introduced during the conversion of the source
       files to man page format. To report such errors, see https://www.kernel.org/doc/man-pages/reporting_bugs.html .

IEEE
/The Open Group						       2013							       TEMPNAM(3P)