mktemp - make a unique temporary filename
char *mktemp(char *template);
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
Never use this function; see BUGS.
- Since glibc 2.12:
- (_XOPEN_SOURCE >= 500) && !
(_POSIX_C_SOURCE >= 200112L)
|| /* Glibc since 2.19: */ _DEFAULT_SOURCE
|| /* Glibc <= 2.19: */ _SVID_SOURCE || _BSD_SOURCE
- Before glibc 2.12:
- _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 500
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.
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.
For an explanation of the terms used in this section, see attributes(7).
- The last six characters of template were not XXXXXX.
4.3BSD, POSIX.1-2001. POSIX.1-2008 removes the specification of mktemp().
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).
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