fix warning tmpnam

libs/main/io_devices/pifile.cpp

@@ -176,14 +176,16 @@ bool PIFile::openTemporary(PIIODevice::DeviceMode mode) {
 	PIString tp;
 #ifdef WINDOWS
 	tp = PIDir::temporary().path() + PIDir::separator + "file" + PIString::fromNumber(randomi());
-#else
-	char * rc = tmpnam(0);
-	if (!rc) return false;
-	tp = rc;
-#endif
 	while (isExists(tp)) {
 		tp += PIString::fromNumber(randomi() % 10);
 	}
+#else
+	char template_rc[] = "/tmp/pifile_tmp_XXXXXX";
+	int fd = mkstemp(template_rc);
+	if (fd == -1) return false;
+	::close(fd);
+	tp = template_rc;
+#endif
 	return open(tp, mode);
 }