SIMPLE SOLUTIONS

MKTEMP - reference manual online

Make a unique temporary filename.

Chapter
2015-08-08
MKTEMP(3)                           Linux Programmer's Manual                           MKTEMP(3)

NAME mktemp - make a unique temporary filename
SYNOPSIS #include <stdlib.h> char *mktemp(char *template); Feature Test Macro Requirements for glibc (see feature_test_macros(7)): mktemp(): Since glibc 2.12: _BSD_SOURCE || _SVID_SOURCE || (_XOPEN_SOURCE >= 500 || _XOPEN_SOURCE && _XOPEN_SOURCE_EXTENDED) && !(_POSIX_C_SOURCE >= 200112L || _XOPEN_SOURCE >= 600) Before glibc 2.12: _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 500 || _XOPEN_SOURCE && _XOPEN_SOURCE_EXTENDED
DESCRIPTION Never use this function; see BUGS. The mktemp() function generates a unique temporary filename from template. The last six characters of template must be XXXXXX and these are replaced with a string that makes the filename unique. Since it will be modified, template must not be a string constant, but should be declared as a character array.
RETURN VALUE The mktemp() function always returns template. If a unique name was created, the last six bytes of template will have been modified in such a way that the resulting name is unique (i.e., does not exist already) If a unique name could not be created, template is made an empty string, and errno is set to indicate the error.
ERRORS EINVAL The last six characters of template were not XXXXXX.
ATTRIBUTES For an explanation of the terms used in this section, see attributes(7). ┌──────────┬───────────────┬─────────┐ │Interface │ Attribute │ Value │ ├──────────┼───────────────┼─────────┤ │mktemp() │ Thread safety │ MT-Safe │ └──────────┴───────────────┴─────────┘
CONFORMING TO 4.3BSD, POSIX.1-2001. POSIX.1-2008 removes the specification of mktemp().
BUGS Never use mktemp(). Some implementations follow 4.3BSD and replace XXXXXX by the current process ID and a single letter, so that at most 26 different names can be returned. Since on the one hand the names are easy to guess, and on the other hand there is a race between testing whether the name exists and opening the file, every use of mktemp() is a security risk. The race is avoided by mkstemp(3) and mkdtemp(3).
SEE ALSO mkdtemp(3), mkstemp(3), tempnam(3), tmpfile(3), tmpnam(3)
COLOPHON This page is part of release 4.04 of the Linux man-pages project. A description of the project, information about reporting bugs, and the latest version of this page, can be found at http://www.kernel.org/doc/man-pages/.
GNU 2015-08-08 MKTEMP(3)
This manual Reference Other manuals
mktemp(3) referred by explain(1) | explain(3) | explain_mktemp(3) | explain_mktemp_or_die(3) | mkdtemp(3) | mkstemp(3) | mktemp(1) | ns_mktemp(3aolserver) | pmRecordAddHost(3) | restore(8) | sudoers(5) | tempnam(3) | tgif(1) | tmpfile(3) | tmpnam(3)
refer to attributes(7) | feature_test_macros(7) | mkdtemp(3) | mkstemp(3) | tempnam(3) | tmpfile(3) | tmpnam(3)