From a085b6fc6c8fa03dac20f01f2f2b64b50b8bdf66 Mon Sep 17 00:00:00 2001 From: Jim Meyering Date: Wed, 11 May 2011 17:13:53 +0200 Subject: ls: allow stat-free use of --color MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Even on a system with d_type support, the default use of --color makes ls stat every file in order to be able to honor settings like EXEC, STICKY, ORPHAN, SETUID, etc., because those settings require information that is not provided by dirent.d_type. However, if for a potentially large performance gain, you are willing to disable those settings, you can now make ls --color give type-related coloring and perform no stat calls at all (other than the unavoidable call-per- command-line argument). Before this change, even with all of those attributes disabled, ls --color would still stat every directory. Now, we're down to the minimum of one stat call per command-line arg. * src/ls.c (gobble_file): With --color, don't stat a non-command-line-specified directory when no directory-coloring attribute is enabled. * tests/init.cfg (require_dirent_d_type_): New function. * tests/d_type-check: New script, mostly from Pádraig Brady. * tests/Makefile.am (EXTRA_DIST): Add it. * tests/ls/stat-free-color: New test. * tests/Makefile.am (TESTS): Add it. * doc/coreutils.texi (General output formatting): Describe how to use dircolors to make ls --color refrain from calling stat on a d_type-enabled file system. Prompted by a query from Josef Bacik. --- tests/Makefile.am | 2 ++ tests/d_type-check | 37 +++++++++++++++++++++++++++++++++ tests/init.cfg | 10 +++++++++ tests/ls/stat-free-color | 54 ++++++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 103 insertions(+) create mode 100644 tests/d_type-check create mode 100755 tests/ls/stat-free-color (limited to 'tests') diff --git a/tests/Makefile.am b/tests/Makefile.am index 6a8b79dcb..9bff3f00f 100644 --- a/tests/Makefile.am +++ b/tests/Makefile.am @@ -10,6 +10,7 @@ EXTRA_DIST = \ CuSkip.pm \ CuTmpdir.pm \ check.mk \ + d_type-check \ envvar-check \ filefrag-extent-compare \ fiemap-capable \ @@ -426,6 +427,7 @@ TESTS = \ ls/rt-1 \ ls/stat-dtype \ ls/stat-failed \ + ls/stat-free-color \ ls/stat-free-symlinks \ ls/stat-vs-dirent \ ls/symlink-slash \ diff --git a/tests/d_type-check b/tests/d_type-check new file mode 100644 index 000000000..e40904907 --- /dev/null +++ b/tests/d_type-check @@ -0,0 +1,37 @@ +#!/usr/bin/python +# Exit 0 if "." has useful d_type information, else 1. +# Intended to exit 0 only on Linux/GNU systems. +import sys + +fail = 1 +try: + import ctypes + + (DT_UNKNOWN, DT_DIR,) = (0, 4,) + + class dirent(ctypes.Structure): + _fields_ = [ + ("d_ino", ctypes.c_long), + ("d_off", ctypes.c_long), + ("d_reclen", ctypes.c_ushort), + ("d_type", ctypes.c_ubyte), + ("d_name", ctypes.c_char*256)] + + direntp = ctypes.POINTER(dirent) + + # FIXME: find a way to hard-coding libc's so-name. + libc = ctypes.cdll.LoadLibrary("libc.so.6") + libc.readdir.restype = direntp + + dirp = libc.opendir(".") + if dirp: + ep = libc.readdir(dirp) + if ep: + name = ep.contents.d_name + if (name == "." or name == "..") and ep.contents.d_type == DT_DIR: + fail = 0 + +except: + pass + +sys.exit(fail) diff --git a/tests/init.cfg b/tests/init.cfg index 92f841f94..55d757175 100644 --- a/tests/init.cfg +++ b/tests/init.cfg @@ -322,6 +322,16 @@ fiemap_capable_() python $abs_srcdir/fiemap-capable "$@" } +# Skip the current test if "." lacks d_type support. +require_dirent_d_type_() +{ + python < /dev/null \ + || skip_test_ python missing: assuming no d_type support + + python $abs_srcdir/d_type-check \ + || skip_test_ requires d_type support +} + # Does the current (working-dir) file system support sparse files? require_sparse_support_() { diff --git a/tests/ls/stat-free-color b/tests/ls/stat-free-color new file mode 100755 index 000000000..d11c6f49c --- /dev/null +++ b/tests/ls/stat-free-color @@ -0,0 +1,54 @@ +#!/bin/sh +# Show that --color need not use stat, as long as we have d_type support. + +# Copyright (C) 2011 Free Software Foundation, Inc. + +# This program is free software: you can redistribute it and/or modify +# it under the terms of the GNU General Public License as published by +# the Free Software Foundation, either version 3 of the License, or +# (at your option) any later version. + +# This program is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. + +# You should have received a copy of the GNU General Public License +# along with this program. If not, see . + +. "${srcdir=.}/init.sh"; path_prepend_ ../src +print_ver_ ls +require_strace_ stat +require_dirent_d_type_ + +ln -s nowhere dangle || framework_failure_ + +# Disable enough features via LS_COLORS so that ls --color +# can do its job without calling stat (other than the obligatory +# one-call-per-command-line argument). +cat < color-without-stat || framework_failure_ +RESET 0 +DIR 01;34 +LINK 01;36 +FIFO 40;33 +SOCK 01;35 +DOOR 01;35 +BLK 40;33;01 +CHR 40;33;01 +ORPHAN 00 +SETUID 00 +SETGID 00 +CAPABILITY 00 +STICKY_OTHER_WRITABLE 00 +OTHER_WRITABLE 00 +STICKY 00 +EXEC 00 +MULTIHARDLINK 00 +EOF +eval $(dircolors -b color-without-stat) + +strace -o log -e stat,lstat ls --color=always . || fail=1 +n_lines=$(wc -l < log) +test $n_lines = 1 || fail=1 + +Exit $fail -- cgit v1.2.3-70-g09d2