function generates a unique temporary filename
The last six characters of template must
be XXXXXX and these are replaced with a string that makes the
Since it will be modified,
must not be a string constant, but should be declared as a character array.
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.
The last six characters of template were not XXXXXX.
POSIX.1-2008 removes the specification of
The prototype is in
for libc4, libc5, glibc1; glibc2 follows the Single Unix Specification
and has the prototype in
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
is a security risk.
The race is avoided by