--- /dev/null
+#include <pwd.h>
+#define T(t) (t*)0;
+#define F(t,n) {t *y = &x.n;}
+static void f()
+{
+T(gid_t)
+T(uid_t)
+T(size_t)
+{
+struct passwd x;
+F(char*,pw_name)
+F(uid_t,pw_uid)
+F(gid_t,pw_gid)
+F(char*,pw_dir)
+F(char*,pw_shell)
+}
+struct passwd*(*p_getpwnam)(const char*) = getpwnam;
+int(*p_getpwnam_r)(const char*,struct passwd*,char*,size_t,struct passwd**) = getpwnam_r;
+struct passwd*(*p_getpwuid)(uid_t) = getpwuid;
+int(*p_getpwuid_r)(uid_t,struct passwd*,char*,size_t,struct passwd**) = getpwuid_r;
+#ifdef _XOPEN_SOURCE
+void(*p_endpwent)(void) = endpwent;
+struct passwd*(*p_getpwent)(void) = getpwent;
+void(*p_setpwent)(void) = setpwent;
+#endif
+}