IEEE/The Open Group
This manual page is part of the POSIX Programmer’s Manual. The Linux implementation of this interface may differ (consult the corresponding Linux manual page for details of Linux behavior), or the interface may not be implemented on Linux.
mktemp - make a unique filename (LEGACY)
char *mktemp(char *template);
The mktemp() function shall replace the contents of the string pointed to by template by a unique filename and return template. The application shall initialize template to be a filename with six trailing ’X’ s; mktemp() shall replace each ’X’ with a single byte character from the portable filename character set.
The mktemp() function shall return the pointer template. If a unique name cannot be created, template shall point to a null string.
No errors are defined.
The following sections are informative.
Generating a Filename
The following example replaces the contents of the "template" string with a 10-character filename beginning with the characters "file" and returns a pointer to the "template" string that contains the new filename.
#include <stdlib.h> ... char *template = "/tmp/fileXXXXXX"; char *ptr;
ptr = mktemp(template);
Between the time a pathname is created and the file opened, it is possible for some other process to create a file with the same name. The mkstemp() function avoids this problem and is preferred over this function.
This function may be withdrawn in a future version.
mkstemp(), tmpfile(), tmpnam(), the Base Definitions volume of IEEE Std 1003.1-2001, <stdlib.h>
Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. 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 Standard is the referee document. The original Standard can be obtained online at http://www.opengroup.org/unix/online.html .