( string dir, string prefix )
Creates a file with a unique filename in the specified directory.
If the directory does not exist, tempnam() may
generate a file in the system's temporary directory, and return
the name of that.
Prior to PHP 4.0.6, the behaviour of the
tempnam() function was system dependent. On
Windows the TMP environment variable will override the
dir parameter, on Linux the TMPDIR
environment variable has precedence, while SVR4 will always use
your dir parameter if the directory it
points to exists. Consult your system documentation on the
tempnam(3) function if in doubt.
If PHP cannot create a file in the specified dir
parameter, it falls back on the system default.
Returns the new temporary filename, or FALSE on
Example 1. tempnam() example
$tmpfname = tempnam("/tmp", "FOO");
$handle = fopen($tmpfname, "w");
fwrite($handle, "writing to tempfile");
// do here something
This function's behavior changed in 4.0.3. The temporary file is also
created to avoid a race condition where the file might appear in the
filesystem between the time the string was generated and before
the script gets around to creating the file. Note, that you need
to remove the file in case you need it no more, it is not done
See also tmpfile() and unlink().