Ls or dir command: list the contents of the current directory
The LS (short for list) command lists the contents of the current directory. The direct command is an alias of the LS command and an abbreviation of directory. Usually, the files listed will be displayed in different colors. Different colors represent different file types. The following table lists the corresponding relationship between file types and colors.
Ls also identifies specific types of files with symbols. The following table lists the common identification symbols and their descriptions.
The LS command has the following format:
Ls [options] directory or file name
The meaning of each option is as follows.
-a: List all files and subdirectories in the specified directory (including implied files).
-A: Same as – A, but not listed. And.
-b: When there is a character in the file name that cannot be displayed, the octal number of the character will be displayed.
-c: Sort by the last modification time of the file.
-C: Display in multiple columns.
-d: Displays the directory name instead of the contents under the directory. It is usually used with – L.
-f: Add the symbol after the listed file name to distinguish different types.
-R: Recursively displays files in all levels of subdirectories of a specified directory.
-s: Gives the number of blocks used for each directory entry, including indirect blocks.
-t: Sort by last modified time (new first, old last).
-l: The detailed information of the file is displayed in long format, including the type and permission of the file, the number of links, the file owner, the group to which the file owner belongs, the file size, the latest modification time and the file name. See Figure 6.4 for details.
The contents of the directory are displayed in different formats as follows:
The code is as follows:
cal_txt finger_txt id_txt newgrp_txt
suple_txt who.txt
finger2_txt groups_txt last_txt suple3_txt
suple_txt～ w.txt
finger3_txt groups_txt2 ln suple3_txt～ w
The code is as follows:
User name, modification time, etc
Total 224
-rw-r–r– 1 root root 2163 07-24 13:00 cal_txt
-rw-r–r– 1 root root 212 07-23 06:37 finger2_txt
-rw-r–r– 1 root root 0 07-23 06:39 finger3_txt
-rw-r–r– 1 root root 248 07-23 06:31 finger_txt
-rw-r–r– 1 root root 35 07-23 04:22 groups_txt
-rw-r–r– 1 root bin 140 07-23 04:32 groups_txt2
-rw-r–r– 1 root root 144 07-23 04:11 id_txt
-rw-r–r– 1 root root 1655 07-22 19:19 last_txt
drwxr-xr-x 5 root root 4096 07-26 09:42 ln
-rw-r–r– 1 root bin 143 07-23 04:24 newgrp_txt
-rw-r–r– 1 root root 25098 07-26 19:15 suple3_txt
-rw-r–r– 1 root root 24031 07-26 16:00 suple3_txt～
-rw-r–r– 1 root root 25198 07-24 20:16 suple_txt
-rw-r–r– 1 root root 24827 07-24 20:06 suple_txt～
-rw-r–r– 2 root root 196 07-23 06:48 w
-rw-r–r– 1 root root 46 07-23 06:48 who.txt
-rw-r–r– 2 root root 196 07-23 06:48 w.txt
The code is as follows:
Total 224
8 cal_txt 8 groups_txt 8 ln
32 suple_txt 8 w.txt
8 finger2_txt 8 groups_txt2 8 newgrp_txt
32 suple_txt～
4 finger3_txt 8 id_txt 32 suple3_txt 8 w
8 finger_txt 8 last_txt 28 suple3_txt～ 8 who.txt
Options can be combined. For example, if you need to list all the contents of the current directory (including those implicit files that start with “.”), and output the file details on the screen in “redundant format”, you can use the option “- Al”. To display all files in the / root directory in redundant format, you can use the following command:
The code is as follows:
drwxr-x— 18 root root 4096 07-26 16:00 .
//Current directory
drwxr-xr-x 24 root root 4096 07-25 05:43 ..
//Parent directory
-rw——- 1 root root 997 07-15 20:58
anaconda- ks.cfg / / normal file
-rw——- 1 root root 2827 07-24 21:32
.bash_ History / / hide files
-rw-r–r– 1 root root 24 2006-07-13
.bash_ Logout / / hide files
… …
The file name “.” indicates the current directory, and the corresponding column lists the details of the current directory. The file name “..” indicates the upper level directory of the current directory, that is, the parent directory. The corresponding column lists the details of the parent directory. The file with “.” symbol in front of the file name is a hidden file, which will be displayed only when “- a” parameter is used.
Determine the file type with ‘ls’ and’ dir ‘commands
Another way to determine the file type is to display a long list of results with the LS and dir commands.
Use LS – L to determine the type of a file.
When you view file permissions, the first character shows the file type, and the other characters show the file permissions.
The code is as follows:
total 6908
drwxr-xr-x 2 tecmint tecmint 4096 Sep 9 11:46 BACKUP
-rw-r–r– 1 tecmint tecmint 1075620 Sep 9 11:47 crossroads-stable.tar.gz
-rwxr—– 1 tecmint tecmint 5916085 Sep 9 11:49 EDWARD-MAYA-2011-2012-NEW-REMIX.mp3
-rw-r–r– 1 tecmint tecmint 42122 Sep 9 11:49 Linux-Security-Optimization-Book.gif
-rw-r–r– 1 tecmint tecmint 17627 Sep 9 11:46 master.zip
-rw-r–r– 1 tecmint tecmint 5 Sep 9 11:48 num.txt
-rw-r–r– 1 tecmint tecmint 0 Sep 9 11:46 reggea.xspf
-rw-r–r– 1 tecmint tecmint 5 Sep 9 11:47 tmp-link
Using LS – L to determine block and character files
The code is as follows:
brw-rw—- 1 root disk 8, 1 Sep 9 10:53 /dev/sda1
The code is as follows:
crw-rw—- 1 root tty 4, 1 Sep 9 10:54 /dev/tty1
Use dir – L to determine the type of a file.
The code is as follows:
total 6908
drwxr-xr-x 2 tecmint tecmint 4096 Sep 9 11:46 BACKUP
-rw-r–r– 1 tecmint tecmint 1075620 Sep 9 11:47 crossroads-stable.tar.gz
-rwxr—– 1 tecmint tecmint 5916085 Sep 9 11:49 EDWARD-MAYA-2011-2012-NEW-REMIX.mp3
-rw-r–r– 1 tecmint tecmint 42122 Sep 9 11:49 Linux-Security-Optimization-Book.gif
-rw-r–r– 1 tecmint tecmint 17627 Sep 9 11:46 master.zip
-rw-r–r– 1 tecmint tecmint 5 Sep 9 11:48 num.txt
-rw-r–r– 1 tecmint tecmint 0 Sep 9 11:46 reggea.xspf
-rw-r–r– 1 tecmint tecmint 5 Sep 9 11:47 tmp-link