#include <stdio.h>

char *tmpnam(char *s);


Partially implemented


IEEE Std 1003.1-2017


The tmpnam() function shall generate a string that is a valid pathname that does not name an existing file. The function is potentially capable of generating TMP_MAX different strings, but any or all of them may already be in use by existing files and thus not be suitable return values.

The tmpnam() function generates a different string each time it is called from the same process, up to TMP_MAX times. If it is called more than TMP_MAX times, the behavior is implementation-defined.

The implementation shall behave as if no function defined in this volume of POSIX.1-2017, except tempnam(), calls tmpnam().

The tmpnam() function need not be thread-safe if called with a NULL parameter.

Return value

Upon successful completion, tmpnam() shall return a pointer to a string. If no suitable string can be generated, the tmpnam() function shall return a null pointer.

If the argument s is a null pointer, tmpnam() shall leave its result in an internal static object and return a pointer to that object. Subsequent calls to tmpnam() may modify the same object. If the argument s is not a null pointer, it is presumed to point to an array of at least L_tmpnam chars; tmpnam() shall write its result in that array and shall return the argument as its value.


No errors are defined.



Known bugs


See Also

  1. Standard library functions
  2. Table of Contents