-struct passwd *getpwuid __P((uid_t));
-struct passwd *getpwnam __P((const char *));
-int getpwuid_r __P((uid_t, struct passwd *, char *, size_t, struct passwd **));
-int getpwnam_r __P((const char *, struct passwd *, char *, size_t, struct passwd **));
-#ifndef _POSIX_SOURCE
-struct passwd *getpwent __P((void));
-#ifndef _XOPEN_SOURCE
-int setpassent __P((int));
-#endif
-int setpwent __P((void));
-void endpwent __P((void));
+struct passwd *getpwuid(uid_t);
+struct passwd *getpwnam(const char *);
+int getpwuid_r(uid_t, struct passwd *, char *, size_t, struct passwd **);
+int getpwnam_r(const char *, struct passwd *, char *, size_t, struct passwd **);
+struct passwd *getpwent(void);
+#if !defined(_POSIX_C_SOURCE) && !defined(_XOPEN_SOURCE)
+int setpassent(int);
+char *user_from_uid(uid_t, int);