It is no exaggeration to say that file operations are the most frequent operations. In Linux, you can use lscommands to list all the contents of the current directory. In this article, we will talk about lscommands first. The files mentioned in this article refer to files and directories.
ls command common options
- -a: Display all subdirectories and files in the specified directory, including hidden files
- -l: Display file details in list mode
- -h: Use with -l to display file size more intuitively
-a
First of all, let's talk about the -a option, a is the abbreviation of all, and this option can display all files in the current directory, mainly to display hidden files.
Hidden files all start with . and are basically files that we do not need to operate on, such as creating a hidden file:
touch .123.txt
Use ls to view:
ls
This file is not present in the listed files at this time .123.txt , we have to add -a, namely:
ls -a
At this point, you see this file, and you may also see hidden files that are already there.
-l
After using the ls command, the results are displayed in rows and only names. After using the -l option, the file will be displayed in the form of a column with very detailed file attributes:
ls -l
result:
total 64 lrwxrwxrwx. 1 root root 7 Oct 15 2017 bin -> usr/bin dr-xr-xr-x. 5 root root 4096 Dec 23 14:31 boot drwxr-xr-x 20 root root 3040 Dec 23 14:30 dev drwxr-xr-x. 80 root root 4096 Dec 23 14:30 etc drwxr-xr-x. 2 root root 4096 Nov 5 2016 home lrwxrwxrwx. 1 root root 7 Oct 15 2017 lib -> usr/lib lrwxrwxrwx. 1 root root 9 Oct 15 2017 lib64 -> usr/lib64 drwx------. 2 root root 16384 Oct 15 2017 lost+found drwxr-xr-x. 2 root root 4096 Nov 5 2016 media drwxr-xr-x. 2 root root 4096 Nov 5 2016 mnt drwxr-xr-x. 2 root root 4096 Nov 5 2016 opt dr-xr-xr-x 73 root root 0 Dec 23 14:30 proc dr-xr-x---. 9 root root 4096 Dec 24 13:33 root drwxr-xr-x 22 root root 620 Dec 23 14:30 run lrwxrwxrwx. 1 root root 8 Oct 15 2017 sbin -> usr/sbin drwxr-xr-x. 2 root root 4096 Nov 5 2016 srv dr-xr-xr-x 13 root root 0 Dec 23 22:30 sys drwxrwxrwt. 8 root root 4096 Apr 19 03:57 tmp drwxr-xr-x. 13 root root 4096 Oct 15 2017 usr drwxr-xr-x. 19 root root 4096 Oct 15 2017 var drwxr-xr-x 3 root root 4096 Dec 24 13:32 workspace
-h
This option should be used with -l, after adding it, the size information of the file will be more intuitive:
ls -h -l
result:
total 64K lrwxrwxrwx. 1 root root 7 Oct 15 2017 bin -> usr/bin dr-xr-xr-x. 5 root root 4.0K Dec 23 14:31 boot drwxr-xr-x 20 root root 3.0K Dec 23 14:30 dev drwxr-xr-x. 80 root root 4.0K Dec 23 14:30 etc drwxr-xr-x. 2 root root 4.0K Nov 5 2016 home lrwxrwxrwx. 1 root root 7 Oct 15 2017 lib -> usr/lib lrwxrwxrwx. 1 root root 9 Oct 15 2017 lib64 -> usr/lib64 drwx------. 2 root root 16K Oct 15 2017 lost+found drwxr-xr-x. 2 root root 4.0K Nov 5 2016 media drwxr-xr-x. 2 root root 4.0K Nov 5 2016 mnt drwxr-xr-x. 2 root root 4.0K Nov 5 2016 opt dr-xr-xr-x 73 root root 0 Dec 23 14:30 proc dr-xr-x---. 9 root root 4.0K Dec 24 13:33 root drwxr-xr-x 22 root root 620 Dec 23 14:30 run lrwxrwxrwx. 1 root root 8 Oct 15 2017 sbin -> usr/sbin drwxr-xr-x. 2 root root 4.0K Nov 5 2016 srv dr-xr-xr-x 13 root root 0 Dec 23 22:30 sys drwxrwxrwt. 8 root root 4.0K Apr 19 03:57 tmp drwxr-xr-x. 13 root root 4.0K Oct 15 2017 usr drwxr-xr-x. 19 root root 4.0K Oct 15 2017 var drwxr-xr-x 3 root root 4.0K Dec 24 13:32 workspace
Compare the results above.
Note: When multiple options are used together, they can be chained together, i.e.:
ls -h -l
can be written as:
ls -hl
The order can also be changed:
ls -lh
Finally, the -a options can be combined:
ls -lha
Try it now~
Let’s talk about so much first, and it’s annoying to see too much. What we want is the effect of small steps and fast running~