【Linux常用命令】 ls
ls == list，根据不同的选项，列举指定目录或文件的相关信息，是Unix/Linux下最常用的命令之一，cd到某一目录下后执行的第一个命令。
ls命令格式：ls [OPTION]... [FILE]...
列举文件信息（默认为当前目录）。
ls
无参数：显示当前目录下的文件和目录（隐藏文件除外）。
Folder: 显示Folder目录中的文件和子目录。
File：显示File文件信息（默认为文件名）。
1 [loong@localhost ~]$ ls
2 Desktop regex src.tar time_test.c vimcdoc-1.7.0 VMwareTools
3 [loong@localhost ~]$ ls /usr
4 bin games kerberos libexec sbin src X11R6
5 etc include lib local share tmp
6 [loong@localhost ~]$ ls time_test.c
7 time_test.c
ls -a
-a选项同ls，但会列举当前目录或者指定目录下的所有文件，包括dot文件（.开头的文件）和.目录和..目录。
1 [loong@localhost ~]$ ls -a /usr
2 . bin games kerberos libexec sbin src X11R6
3 .. etc include lib local share tmp
ls -A
-A选项同ls，但会列举当前目录或者指定目录下的所有文件，包括dot文件（.开头的文件），但不包括.目录和..目录。
1 [loong@localhost ~]$ ls -A /usr
2 bin games kerberos libexec sbin src X11R6
3 etc include lib local share tmp
ls -l
-l选项的ls命令将列举当前目录或指定目录中文件或者子目录的详析信息。
1 [loong@localhost ~]$ ls -l
2 total 48
3 drwxr-xr-x 3 loong loong 4096 Mar 27 21:12 Desktop
4 drwxrwxr-x 2 loong loong 4096 Jan 13 16:01 regex
5 drwxrwxr-x 6 loong loong 4096 Feb 15 10:57 src.tar
6 -rw-rw-r-- 1 loong loong 153 Mar 27 19:47 time_test.c
7 drwxrwxrwx 3 loong loong 4096 Mar 27 19:29 vimcdoc-1.7.0
8 drwxrwxr-x 3 loong loong 4096 Jan 10 00:18 VMwareTools
ls -l列举的信息包含7个以Tab的域：
- 第一个域：第一个字符指明了文件类型
- -: 普通文件；
- d: 目录文件；
- l: 符号链接；
- s: socket文件；
- b: 块设备；
- c: 字符设备；
- p: 管道文件。
后面的9个字符指明了文件的访问权限：每三位指明一类用户的权限，分别是文件属主、同组用户、其它用户，权限分为读（r）、写（w）、执行（x）。
- 第二个域：链接数。普通文件至少为1，目录至少为2（.和..）；
- 第三域：文件属主；
- 第四域：用户组；
- 第五域：文件大小，其中目录大小通常为块大小的整数倍；
- 第六域：文件的最近修改日期和时间，修改文件意味着对其内文件或子目录的增添和修改；
- 第七域：文件名
ls -t
按文件的修改时间列举文件，最近修改的在前。
1 [loong@localhost ~]$ ls
2 Desktop regex src.tar time_test.c vimcdoc-1.7.0 VMwareTools
3 [loong@localhost ~]$ ls -t
4 Desktop time_test.c vimcdoc-1.7.0 src.tar regex VMwareTools
ls -r
以相反顺序列举文件。
1 [loong@localhost ~]$ ls
2 Desktop regex src.tar time_test.c vimcdoc-1.7.0 VMwareTools
3 [loong@localhost ~]$ ls -r
4 VMwareTools vimcdoc-1.7.0 time_test.c src.tar regex Desktop
ls -1
单独行列举文件。
1 [loong@localhost ~]$ ls
2 Desktop regex src.tar time_test.c vimcdoc-1.7.0 VMwareTools
3 [loong@localhost ~]$ ls -1
4 Desktop
5 regex
6 src.tar
7 time_test.c
8 vimcdoc-1.7.0
9 VMwareTools
ls -F
可视化显示文件类型。
1 [loong@localhost ~]$ ls
2 Desktop regex src.tar time_test.c vimcdoc-1.7.0 VMwareTools
3 [loong@localhost ~]$ ls -F
4 Desktop/ regex/ src.tar/ time_test.c vimcdoc-1.7.0/ VMwareTools/
- / ： 目录
- nothing ： 普通文件.
- @ ：符号链接文件
- * ：可执行文件
ls -latr
组合选项，即是说，各个选项可以结合使用，除了互相排斥的选项，例如-a和-A。
1 [loong@localhost Desktop]$ ls
2 VMwareTools-8.1.4-227600.tar.gz vmware-tools-distrib
3 [loong@localhost Desktop]$ ls -latr
4 total 94984
5 drwxr-xr-x 7 loong loong 4096 Jan 23 2010 vmware-tools-distrib
6 -r--r--r-- 1 loong loong 97129687 Jan 23 2010 VMwareTools-8.1.4-227600.tar.gz
7 drwxr-xr-x 3 loong loong 4096 Mar 27 21:12 .
8 drwx------ 28 loong loong 4096 Mar 27 21:34 ..
使用alias
使用alias会更加方便，我系统当前帐号中定义的alias有：
1 [loong@localhost Desktop]$ alias
2 alias l.='ls -d .* --color=tty'
3 alias ll='ls -l --color=tty'
4 alias ls='ls --color=tty'
5 alias vi='vim'
6 alias which='alias | /usr/bin/which --tty-only --read-alias --show-dot --show-tilde'
7 [loong@localhost Desktop]$ l.
8 . ..
9 [loong@localhost Desktop]$ ll
10 total 94968
11 -r--r--r-- 1 loong loong 97129687 Jan 23 2010 VMwareTools-8.1.4-227600.tar.gz
12 drwxr-xr-x 7 loong loong 4096 Jan 23 2010 vmware-tools-distrib
ps：前3个alias定义在/etc/profile.d/目录下的colorls.csh和colorls.sh中，具体是哪个就不清楚了。
系统信息：
1 [loong@localhost /]$ cat /etc/redhat-release
2 CentOS release 5.7 (Final)
3 [loong@localhost /]$ uname -a
4 Linux localhost.localdomain 2.6.18-274.18.1.el5 #1 SMP Thu Feb 9 12:45:52 EST 2012 i686 i686 i386 GNU/Linux
以上参考：http://www.dutor.net/index.php/2010/06/cmd-ls/
模糊列举: 其中，*代表任意个字符（包括0个），?代表一个字符。
ls /etc/a*e
列出/etc/目录下以字母a开头且以字母e结尾的目录和文件。
1 [loong@localhost /]$ ls /etc/a*e
2 /etc/adjtime /etc/asound.state
ls /bin/l?
列出/bin/目录下以字母b开头的目录和文件，且目录名或文件名的长度为2.
1 [loong@localhost /]$ ls /bin/l?
2 /bin/ln /bin/ls
ls |more
当要显示的文件数太多（如/usr/bin/下的文件），这是一页屏不能显示，如果直接运行“ls /usr/bin”，则不能看见最前面的文件。这时用到通道“|more”，来显示多页屏输出（按空格显示下一页，回车显示下一行）。
1 [loong@localhost /]$ ls /usr/bin |more
2 [
3 411toppm
4 a2p
5 a2ps
6 ab
7 ac
8 aconnect
9 acpi_listen
10 activation-client
11 addftinfo
12 addr2line
13 addresses
14 afs5log
15 alacarte
16 alsamixer
17 amidi
18 amixer
19 amtu
20 amuFormat.sh
21 animate
22 anytopnm
23 aplay
24 aplaymidi
25 --More--
【注】此用法类似与windows下的cmd命令“dir /p”。
最后，附上ls的英文manual（Linux的man命令）。
man ls
1 LS(1) User Commands LS(1)
2
3 NAME
4 ls - list directory contents
5
6 SYNOPSIS
7 ls [OPTION]... [FILE]...
8
9 DESCRIPTION
10 List information about the FILEs (the current directory by default). Sort entries alphabetically if
11 none of -cftuvSUX nor --sort.
12
13 Mandatory arguments to long options are mandatory for short options too.
14
15 -a, --all
16 do not ignore entries starting with .
17
18 -A, --almost-all
19 do not list implied . and ..
20
21 --author
22 with -l, print the author of each file
23
24 -b, --escape
25 print octal escapes for nongraphic characters
26
27 --block-size=SIZE
28 use SIZE-byte blocks
29
30 -B, --ignore-backups
31 do not list implied entries ending with ~
32
33 -c with -lt: sort by, and show, ctime (time of last modification of file status information) with
34 -l: show ctime and sort by name otherwise: sort by ctime
35
36 -C list entries by columns
37
38 --color[=WHEN]
39 control whether color is used to distinguish file types. WHEN may be ¡®never¡¯, ¡®always¡¯, or
40 ¡®auto¡¯
41
42 -d, --directory
43 list directory entries instead of contents, and do not dereference symbolic links
44
45 -D, --dired
46 generate output designed for Emacs¡¯ dired mode
47
48 -f do not sort, enable -aU, disable -lst
49
50 -F, --classify
51 append indicator (one of */=>@|) to entries
52
53 --file-type
54 likewise, except do not append ¡®*¡¯
55
56 --format=WORD
57 across -x, commas -m, horizontal -x, long -l, single-column -1, verbose -l, vertical -C
58
59 --full-time
60 like -l --time-style=full-iso
61
62 -g like -l, but do not list owner
63
64 -G, --no-group
65 like -l, but do not list group
66
67 -h, --human-readable
68 with -l, print sizes in human readable format (e.g., 1K 234M 2G)
69
70 --si likewise, but use powers
71
72 -H, --dereference-command-line
73 follow symbolic links listed on the command line
74
75 --dereference-command-line-symlink-to-dir
76 follow each command line symbolic link that points to a directory
77
78 --hide=PATTERN
79 do not list implied entries matching shell PATTERN (overridden by -a or -A)
80
81 --indicator-style=WORD append indicator with style WORD to entry names:
82 none (default), slash (-p), file-type (--file-type), classify (-F)
83
84 -i, --inode
85 with -l, print the index number of each file
86
87 -I, --ignore=PATTERN
88 do not list implied entries matching shell PATTERN
89
90 -k like --block-size=1K
91
92 -l use a long listing format
93
94 -L, --dereference
95 when showing file information for a symbolic link, show information for the file the link refer-
96 ences rather than for the link itself
97
98 -m fill width with a comma separated list of entries
99
100 -n, --numeric-uid-gid
101 like -l, but list numeric user and group IDs
102
103 -N, --literal
104 print raw entry names (don¡¯t treat e.g. control characters specially)
105
106 -o like -l, but do not list group information
107
108 -p, --indicator-style=slash
109 append / indicator to directories
110
111 -q, --hide-control-chars
112 print ? instead of non graphic characters
113
114 --show-control-chars
115 show non graphic characters as-is (default unless program is ¡®ls¡¯ and output is a terminal)
116
117 -Q, --quote-name
118 enclose entry names in double quotes
119
120 --quoting-style=WORD
121 use quoting style WORD for entry names: literal, locale, shell, shell-always, c, escape
122
123 -r, --reverse
124 reverse order while sorting
125
126 -R, --recursive
127 list subdirectories recursively
128
129 -s, --size
130 with -l, print size of each file, in blocks
131
132 -S sort by file size
133
134 --sort=WORD
135 extension -X, none -U, size -S, time -t, version -v, status -c, time -t, atime -u, access -u, use
136 -u
137
138 --time=WORD
139 with -l, show time as WORD instead of modification time: atime, access, use, ctime or status; use
140 specified time as sort key if --sort=times
141
142
143 --time-style=STYLE
144 with -l, show times using style STYLE: full-iso, long-iso, iso, locale, +FORMAT. FORMAT is
145 interpreted like ‘date’; if FORMAT is FORMAT1<newline>FORMAT2, FORMAT1 applies to non-recent
146 files and FORMAT2 to recent files; if STYLE is prefixed with ‘posix-’, STYLE takes effect only
147 outside the POSIX locale
148
149 -t sort by modification time
150
151 -T, --tabsize=COLS
152 assume tab stops at each COLS instead of 8
153
154 -u with -lt: sort by, and show, access time with -l: show access time and sort by name otherwise:
155 sort by access time
156
157 -U do not sort; list entries in directory order. In combination with one_per_line format ‘-1’, it
158 will show files immediately and it has no memory limitations.
159
160 -v sort by version
161
162 -w, --width=COLS
163 assume screen width instead of current value
164
165 -x list entries by lines instead of by columns
166
167 -X sort alphabetically by entry extension
168
169 -1 list one file per line
170
171 SELinux options:
172
173 --lcontext
174 Display security context. Enable -l. Lines will probably be too wide for most displays.
175
176 -Z, --context
177 Display security context so it fits on most displays. Displays only mode, user, group, security
178 context and file name.
179
180 --scontext
181 Display only security context and file name.
182
183 --help display this help and exit
184
185 --version
186 output version information and exit
187
188 SIZE may be (or may be an integer optionally followed by) one of following: kB 1000, K 1024, MB
189 1000*1000, M 1024*1024, and so on for G, T, P, E, Z, Y.
190
191 By default, color is not used to distinguish types of files. That is equivalent to using --color=none.
192 Using the --color option without the optional WHEN argument is equivalent to using --color=always. With
193 --color=auto, color codes are output only if standard output is connected to a terminal (tty). The
194 environment variable LS_COLORS can influence the colors, and can be set easily by the dircolors command.
195
196 Exit status is 0 if OK, 1 if minor problems, 2 if serious trouble.
197
198 AUTHOR
199 Written by Richard Stallman and David MacKenzie.
200
201 REPORTING BUGS
202 Report bugs to <bug-coreutils@gnu.org>.
203
204 COPYRIGHT
205 Copyright © 2006 Free Software Foundation, Inc.
206 This is free software. You may redistribute copies of it under the terms of the GNU General Public
207 License <http://www.gnu.org/licenses/gpl.html>. There is NO WARRANTY, to the extent permitted by law.
208
209 SEE ALSO
210 The full documentation for ls is maintained as a Texinfo manual. If the info and ls programs are prop-
211 erly installed at your site, the command
212
213 info ls
214
215 should give you access to the complete manual.
216
217 ls 5.97 July 2011 LS(1)
