|MKTEMP(3)||Linux Programmer's Manual||MKTEMP(3)|
mktemp - make a unique temporary filename
char *mktemp(char *template);
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.
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.
- The last six characters of template were not XXXXXX.
For an explanation of the terms used in this section, see attributes(7).
|mktemp ()||Thread safety||MT-Safe|
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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