linux命令详解之ls命令
ls命令概述
ls命令用于显示文件目录列表，和Windows系统下DOS命令dir类似。当执行ls命令时，默认显示的只有非隐藏文件的文件名、以文件名进行排序及文件名代表的颜色显示。当不加参数时，默认列出当前目录的列表信息。ls命令使用频率非常高，参数也非常多，多达四五十个，本文只介绍一部分常用的参数，其他参数可以通过man命令查看帮助手册。
说明：在linux下，文件名以点.开头表示该文件为隐藏文件，如.bashrc。
ls命令语法
ls [选项] [目录或文件名]
参数：
-a：--all的缩写，显示所有的文件，包括隐藏文件(以.开头的文件)，参考示例1。(常用)
-A：--almost-all的缩写，显示所有的文件，包括隐藏文件，但不包括表示当前目录.和上级目录..这两个文件，参考示例2。
-c：和-lt一起使用：显示列表并且以ctime(文件状态最后改变时间)排序。和-l一起使用：显示ctime并且以文件名排序。其他情况，以ctime排序。参考示例3。
-d：--directory的缩写，仅列出目录本身，而不是列出目录里的内容列表，参考示例4。(常用)
-f：直接列出结果，而不进行排序(ls默认会以文件名排序)
--color[=WHEN]：是否根据文件类型显示颜色，WHEN可以为never、always或者auto
--full-time：以完整的实际模式显示(包含年月日时分)，类似与ls -l --time-style=full-iso，参考示例5。
-g：列表显示结果，和-l类似，但是不显示文件所属者。
-h：将文件内容大小以GB、KB等易读的方式显示，参考示例6。
-i：结合-l参数，列出每个文件的inode，参考示例7。
-l：列出长数据串，显示出文件的属性与权限等数据信息(常用)
-n：和-l类似，只是显示的所属用户和组不是名称而是对应的id，参考示例8。
-r：--reverse，将排序结果以倒序方式显示，参考示例9。
-S：以文件大小排序，参考示例9。
-t：以修改时间排序
--help：显示帮助信息
ls命令示例
示例1：列出所有文件(注意和-A参数的区别，结果里面包括表示当前目录.和上级目录..这两个文件)。
[root@localhost ~]# ls -a #列出所有文件
. .. .bash_history .bash_logout .bash_profile .bashrc install.log install.log.syslog
[root@localhost ~]# ls --all
. .. .bash_history .bash_logout .bash_profile .bashrc install.log install.log.syslog示例2：列出所有的文件，但不包括表示当前目录.和上级目录..这两个文件。
[root@localhost ~]# ls -A
.bash_history .bash_logout .bash_profile .bashrc install.log install.log.syslog
[root@localhost ~]# ls --almost-all
.bash_history .bash_logout .bash_profile .bashrc install.log install.log.syslog示例3：显示列表并且以ctime排序
[root@localhost /]# ls -clt #和 -lt参数一起使用，以时间排序
total 146
drwxrwxrwt 7 root root 4096 Apr 13 06:23 tmp
drwxr-xr-x 12 root root 4440 Apr 13 05:18 dev
drwxr-xr-x 93 root root 12288 Apr 13 05:18 etc
drwxr-xr-x 2 root root 0 Apr 13 05:18 net
drwxr-xr-x 2 root root 0 Apr 13 05:18 misc
drwxr-xr-x 4 root root 0 Apr 13 05:16 selinux
drwxr-xr-x 11 root root 0 Apr 13 05:16 sys
dr-xr-xr-x 150 root root 0 Apr 13 05:16 proc
drwxr-xr-x 2 root root 12288 Mar 28 06:34 sbin
drwxr-xr-x 2 root root 4096 Mar 28 06:33 bin
drwxr-xr-x 8 root root 4096 Mar 28 06:33 lib64
drwxr-x--- 4 root root 4096 Nov 19 06:52 root
drwxr-xr-x 4 root root 4096 Nov 18 22:05 home
drwxr-xr-x 11 root root 4096 Nov 14 06:13 lib
drwxr-xr-x 3 root root 4096 Oct 17 2015 mnt
drwxr-xr-x 22 root root 4096 Oct 17 2015 var
drwxr-xr-x 4 root root 1024 Oct 17 2015 boot
drwxr-xr-x 15 root root 4096 Oct 17 2015 usr
drwxr-xr-x 2 root root 4096 Oct 17 2015 media
drwxr-xr-x 2 root root 4096 Oct 17 2015 srv
drwx------ 2 root root 16384 Oct 17 2015 lost+found
drwxr-xr-x 3 root root 4096 Oct 17 2015 opt
[root@localhost /]# ls -cl #和-l参数一起使用，以文件名排序并显示时间
total 146
drwxr-xr-x 2 root root 4096 Mar 28 06:33 bin
drwxr-xr-x 4 root root 1024 Oct 17 2015 boot
drwxr-xr-x 12 root root 4440 Apr 13 05:18 dev
drwxr-xr-x 93 root root 12288 Apr 13 05:18 etc
drwxr-xr-x 4 root root 4096 Nov 18 22:05 home
drwxr-xr-x 11 root root 4096 Nov 14 06:13 lib
drwxr-xr-x 8 root root 4096 Mar 28 06:33 lib64
drwx------ 2 root root 16384 Oct 17 2015 lost+found
drwxr-xr-x 2 root root 4096 Oct 17 2015 media
drwxr-xr-x 2 root root 0 Apr 13 05:18 misc
drwxr-xr-x 3 root root 4096 Oct 17 2015 mnt
drwxr-xr-x 2 root root 0 Apr 13 05:18 net
drwxr-xr-x 3 root root 4096 Oct 17 2015 opt
dr-xr-xr-x 150 root root 0 Apr 13 05:16 proc
drwxr-x--- 4 root root 4096 Nov 19 06:52 root
drwxr-xr-x 2 root root 12288 Mar 28 06:34 sbin
drwxr-xr-x 4 root root 0 Apr 13 05:16 selinux
drwxr-xr-x 2 root root 4096 Oct 17 2015 srv
drwxr-xr-x 11 root root 0 Apr 13 05:16 sys
drwxrwxrwt 7 root root 4096 Apr 13 06:23 tmp
drwxr-xr-x 15 root root 4096 Oct 17 2015 usr
drwxr-xr-x 22 root root 4096 Oct 17 2015 var
[root@localhost /]# ls -c #单独使用，以时间排序，但不显示时间
tmp dev etc net misc selinux sys proc sbin bin lib64 root home lib mnt var boot usr media srv lost+found opt示例4：仅仅列出目录本身，不需要列出目录里的内容
[root@localhost /]# ls -d /home #仅列出/home目录本身
/home
[root@localhost /]# ls /home #列出/home目录里的内容
sgl software
# 加上-l参数，比较的更清楚一些：
[root@localhost /]# ls -ld /home
drwxr-xr-x 4 root root 4096 Nov 18 22:05 /home
[root@localhost /]# ls -l /home
total 16
drwx------ 16 sgl sgl 4096 Oct 17 2015 sgl
drwxr-xr-x 3 root root 4096 Nov 14 05:13 software
示例5：显示完整时间
[root@localhost ~]# ls --full-time /
total 146
drwxr-xr-x 2 root root 4096 2017-03-28 06:33:59.000000000 -0700 bin
drwxr-xr-x 4 root root 1024 2015-10-17 08:08:24.000000000 -0700 boot
drwxr-xr-x 12 root root 4440 2017-04-14 21:22:27.241239736 -0700 dev
drwxr-xr-x 93 root root 12288 2017-04-14 21:22:24.000000000 -0700 etc
drwxr-xr-x 4 root root 4096 2016-11-18 22:05:32.000000000 -0800 home
drwxr-xr-x 11 root root 4096 2016-11-14 06:13:35.000000000 -0800 lib
drwxr-xr-x 8 root root 4096 2017-03-28 06:33:33.000000000 -0700 lib64
drwx------ 2 root root 16384 2015-10-17 08:01:52.000000000 -0700 lost+found
drwxr-xr-x 2 root root 4096 2011-05-11 04:58:23.000000000 -0700 media
drwxr-xr-x 2 root root 0 2017-04-14 21:22:23.789239736 -0700 misc
drwxr-xr-x 3 root root 4096 2015-10-17 08:16:39.000000000 -0700 mnt
drwxr-xr-x 2 root root 0 2017-04-14 21:22:23.839239736 -0700 net
drwxr-xr-x 3 root root 4096 2015-10-17 00:17:25.000000000 -0700 opt
dr-xr-xr-x 147 root root 0 2017-04-14 21:21:02.005999666 -0700 proc
drwxr-x--- 4 root root 4096 2016-11-19 06:52:09.000000000 -0800 root
drwxr-xr-x 2 root root 12288 2017-03-28 06:34:07.000000000 -0700 sbin
drwxr-xr-x 4 root root 0 2017-04-14 21:21:02.671999847 -0700 selinux
drwxr-xr-x 2 root root 4096 2011-05-11 04:58:23.000000000 -0700 srv
drwxr-xr-x 11 root root 0 2017-04-14 21:21:02.657999847 -0700 sys
drwxrwxrwt 7 root root 4096 2017-04-14 21:24:24.000000000 -0700 tmp
drwxr-xr-x 15 root root 4096 2015-10-17 08:04:13.000000000 -0700 usr
drwxr-xr-x 22 root root 4096 2015-10-17 08:11:05.000000000 -0700 var示例6：以易读方式显示列表
[root@localhost ~]# ls -lh / #注意列表容量大小列的单位
total 146K
drwxr-xr-x 2 root root 4.0K Mar 28 06:33 bin
drwxr-xr-x 4 root root 1.0K Oct 17 2015 boot
drwxr-xr-x 12 root root 4.4K Apr 14 21:22 dev
drwxr-xr-x 93 root root 12K Apr 14 21:22 etc
drwxr-xr-x 4 root root 4.0K Nov 18 22:05 home
drwxr-xr-x 11 root root 4.0K Nov 14 06:13 lib
drwxr-xr-x 8 root root 4.0K Mar 28 06:33 lib64
drwx------ 2 root root 16K Oct 17 2015 lost+found
drwxr-xr-x 2 root root 4.0K May 11 2011 media
drwxr-xr-x 2 root root 0 Apr 14 21:22 misc
drwxr-xr-x 3 root root 4.0K Oct 17 2015 mnt
drwxr-xr-x 2 root root 0 Apr 14 21:22 net
drwxr-xr-x 3 root root 4.0K Oct 17 2015 opt
dr-xr-xr-x 147 root root 0 Apr 14 21:21 proc
drwxr-x--- 4 root root 4.0K Nov 19 06:52 root
drwxr-xr-x 2 root root 12K Mar 28 06:34 sbin
drwxr-xr-x 4 root root 0 Apr 14 21:21 selinux
drwxr-xr-x 2 root root 4.0K May 11 2011 srv
drwxr-xr-x 11 root root 0 Apr 14 21:21 sys
drwxrwxrwt 7 root root 4.0K Apr 14 21:24 tmp
drwxr-xr-x 15 root root 4.0K Oct 17 2015 usr
drwxr-xr-x 22 root root 4.0K Oct 17 2015 var
[root@localhost ~]# ls -l / #默认方式，以字节为单位显示
total 146
drwxr-xr-x 2 root root 4096 Mar 28 06:33 bin
drwxr-xr-x 4 root root 1024 Oct 17 2015 boot
drwxr-xr-x 12 root root 4440 Apr 14 21:22 dev
drwxr-xr-x 93 root root 12288 Apr 14 21:22 etc
drwxr-xr-x 4 root root 4096 Nov 18 22:05 home
drwxr-xr-x 11 root root 4096 Nov 14 06:13 lib
drwxr-xr-x 8 root root 4096 Mar 28 06:33 lib64
drwx------ 2 root root 16384 Oct 17 2015 lost+found
drwxr-xr-x 2 root root 4096 May 11 2011 media
drwxr-xr-x 2 root root 0 Apr 14 21:22 misc
drwxr-xr-x 3 root root 4096 Oct 17 2015 mnt
drwxr-xr-x 2 root root 0 Apr 14 21:22 net
drwxr-xr-x 3 root root 4096 Oct 17 2015 opt
dr-xr-xr-x 147 root root 0 Apr 14 21:21 proc
drwxr-x--- 4 root root 4096 Nov 19 06:52 root
drwxr-xr-x 2 root root 12288 Mar 28 06:34 sbin
drwxr-xr-x 4 root root 0 Apr 14 21:21 selinux
drwxr-xr-x 2 root root 4096 May 11 2011 srv
drwxr-xr-x 11 root root 0 Apr 14 21:21 sys
drwxrwxrwt 7 root root 4096 Apr 14 21:24 tmp
drwxr-xr-x 15 root root 4096 Oct 17 2015 usr
drwxr-xr-x 22 root root 4096 Oct 17 2015 var示例7：显示inode
[root@localhost ~]# ls -li /
total 146
3717313 drwxr-xr-x 2 root root 4096 Mar 28 06:33 bin
2 drwxr-xr-x 4 root root 1024 Oct 17 2015 boot
1071 drwxr-xr-x 12 root root 4440 Apr 14 21:22 dev
1369537 drwxr-xr-x 93 root root 12288 Apr 14 21:22 etc
1402145 drwxr-xr-x 4 root root 4096 Nov 18 22:05 home
2380385 drwxr-xr-x 11 root root 4096 Nov 14 06:13 lib
2184737 drwxr-xr-x 8 root root 4096 Mar 28 06:33 lib64
11 drwx------ 2 root root 16384 Oct 17 2015 lost+found
195649 drwxr-xr-x 2 root root 4096 May 11 2011 media
14244 drwxr-xr-x 2 root root 0 Apr 14 21:22 misc
1434753 drwxr-xr-x 3 root root 4096 Oct 17 2015 mnt
14249 drwxr-xr-x 2 root root 0 Apr 14 21:22 net
391297 drwxr-xr-x 3 root root 4096 Oct 17 2015 opt
1 dr-xr-xr-x 147 root root 0 Apr 14 21:21 proc
65217 drwxr-x--- 4 root root 4096 Nov 19 06:52 root
3554273 drwxr-xr-x 2 root root 12288 Mar 28 06:34 sbin
591 drwxr-xr-x 4 root root 0 Apr 14 21:21 selinux
1956481 drwxr-xr-x 2 root root 4096 May 11 2011 srv
1 drwxr-xr-x 11 root root 0 Apr 14 21:21 sys
3815137 drwxrwxrwt 7 root root 4096 Apr 14 21:24 tmp
3456449 drwxr-xr-x 15 root root 4096 Oct 17 2015 usr
2576033 drwxr-xr-x 22 root root 4096 Oct 17 2015 var示例8：列出文件夹内容，并显示出文件所属用户和组的id
[root@localhost ~]# ls -ln /
total 146
drwxr-xr-x 2 0 0 4096 Mar 28 06:33 bin
drwxr-xr-x 4 0 0 1024 Oct 17 2015 boot
drwxr-xr-x 12 0 0 4440 Apr 14 21:22 dev
drwxr-xr-x 93 0 0 12288 Apr 14 21:22 etc
drwxr-xr-x 4 0 0 4096 Nov 18 22:05 home
drwxr-xr-x 11 0 0 4096 Nov 14 06:13 lib
drwxr-xr-x 8 0 0 4096 Mar 28 06:33 lib64
drwx------ 2 0 0 16384 Oct 17 2015 lost+found
drwxr-xr-x 2 0 0 4096 May 11 2011 media
drwxr-xr-x 2 0 0 0 Apr 14 21:22 misc
drwxr-xr-x 3 0 0 4096 Oct 17 2015 mnt
drwxr-xr-x 2 0 0 0 Apr 14 21:22 net
drwxr-xr-x 3 0 0 4096 Oct 17 2015 opt
dr-xr-xr-x 147 0 0 0 Apr 14 21:21 proc
drwxr-x--- 4 0 0 4096 Nov 19 06:52 root
drwxr-xr-x 2 0 0 12288 Mar 28 06:34 sbin
drwxr-xr-x 4 0 0 0 Apr 14 21:21 selinux
drwxr-xr-x 2 0 0 4096 May 11 2011 srv
drwxr-xr-x 11 0 0 0 Apr 14 21:21 sys
drwxrwxrwt 7 0 0 4096 Apr 14 21:24 tmp
drwxr-xr-x 15 0 0 4096 Oct 17 2015 usr
drwxr-xr-x 22 0 0 4096 Oct 17 2015 var示例9：以文件大小排序(升序和降序)
[root@localhost ~]# ls -lS / #默认降序排序
total 146
drwx------ 2 root root 16384 Oct 17 2015 lost+found
drwxr-xr-x 93 root root 12288 Apr 14 21:22 etc
drwxr-xr-x 2 root root 12288 Mar 28 06:34 sbin
drwxr-xr-x 12 root root 4440 Apr 14 21:22 dev
drwxr-xr-x 2 root root 4096 Mar 28 06:33 bin
drwxr-xr-x 4 root root 4096 Nov 18 22:05 home
drwxr-xr-x 11 root root 4096 Nov 14 06:13 lib
drwxr-xr-x 8 root root 4096 Mar 28 06:33 lib64
drwxr-xr-x 2 root root 4096 May 11 2011 media
drwxr-xr-x 3 root root 4096 Oct 17 2015 mnt
drwxr-xr-x 3 root root 4096 Oct 17 2015 opt
drwxr-x--- 4 root root 4096 Nov 19 06:52 root
drwxr-xr-x 2 root root 4096 May 11 2011 srv
drwxrwxrwt 7 root root 4096 Apr 14 21:24 tmp
drwxr-xr-x 15 root root 4096 Oct 17 2015 usr
drwxr-xr-x 22 root root 4096 Oct 17 2015 var
drwxr-xr-x 4 root root 1024 Oct 17 2015 boot
drwxr-xr-x 2 root root 0 Apr 14 21:22 misc
drwxr-xr-x 2 root root 0 Apr 14 21:22 net
dr-xr-xr-x 147 root root 0 Apr 14 21:21 proc
drwxr-xr-x 4 root root 0 Apr 14 21:21 selinux
drwxr-xr-x 11 root root 0 Apr 14 21:21 sys
[root@localhost ~]# ls -lSr / #通过-r参数实现升序排列
total 146
drwxr-xr-x 11 root root 0 Apr 14 21:21 sys
drwxr-xr-x 4 root root 0 Apr 14 21:21 selinux
dr-xr-xr-x 147 root root 0 Apr 14 21:21 proc
drwxr-xr-x 2 root root 0 Apr 14 21:22 net
drwxr-xr-x 2 root root 0 Apr 14 21:22 misc
drwxr-xr-x 4 root root 1024 Oct 17 2015 boot
drwxr-xr-x 22 root root 4096 Oct 17 2015 var
drwxr-xr-x 15 root root 4096 Oct 17 2015 usr
drwxrwxrwt 7 root root 4096 Apr 14 21:24 tmp
drwxr-xr-x 2 root root 4096 May 11 2011 srv
drwxr-x--- 4 root root 4096 Nov 19 06:52 root
drwxr-xr-x 3 root root 4096 Oct 17 2015 opt
drwxr-xr-x 3 root root 4096 Oct 17 2015 mnt
drwxr-xr-x 2 root root 4096 May 11 2011 media
drwxr-xr-x 8 root root 4096 Mar 28 06:33 lib64
drwxr-xr-x 11 root root 4096 Nov 14 06:13 lib
drwxr-xr-x 4 root root 4096 Nov 18 22:05 home
drwxr-xr-x 2 root root 4096 Mar 28 06:33 bin
drwxr-xr-x 12 root root 4440 Apr 14 21:22 dev
drwxr-xr-x 2 root root 12288 Mar 28 06:34 sbin
drwxr-xr-x 93 root root 12288 Apr 14 21:22 etc
drwx------ 2 root root 16384 Oct 17 2015 lost+found
注：本系列内容主要参考《鸟哥的linux私房菜》和CentOS系统自带的帮助文档以及网上相关资料，示例都是基于CentOS。