AC_CHECK_FUNCS_ONCE([fchmod fchown fsync lstat mkfifo readlink symlink])
AC_CHECK_DECLS([getgrgid],,, [#include <grp.h>])
AC_CHECK_DECLS([getpwuid],,, [#include <pwd.h>])
AC_CHECK_FUNCS_ONCE([fchmod fchown fsync lstat mkfifo readlink symlink])
AC_CHECK_DECLS([getgrgid],,, [#include <grp.h>])
AC_CHECK_DECLS([getpwuid],,, [#include <pwd.h>])