Catalog management
Absolute path and relative path
We know that the Linux directory structure is a tree structure, and the top directory is the root directory /.
Other directories can be added to the tree by mounting, and they can be removed by unmounting.
Before starting this tutorial, we need to know what an absolute path and a relative path are.
Absolute path:
The path is written from the root directory /, for example: /usr/share/doc this directory.
relative path:
The path is not written from /. For example, when going from /usr/share/doc to /usr/share/man, you can write: cd …/man This is the way of writing relative paths!
Common commands for handling directories
Next, let's look at a few common commands for handling directories:
- ls: list directories
- cd: switch directory
- pwd: display the current directory
- mkdir: create a new directory
- rmdir: delete an empty directory
- cp: copy files or directories
- rm: remove files or directories
- mv: Move files and directories, or modify the names of files and directories
You can use man [command] to view the documentation of each command, such as man cp.
ls (list directories)
Among Linux systems, the ls command is probably the most frequently run.
grammar:
[root@www ~]# ls [-aAdfFhilnrRSt] 目录名称
Options and parameters:
- -a: All files, together with hidden files (files starting with .) are listed together (commonly used)
- -l: List long data strings, including file attributes and permissions, etc.; (commonly used)
List all files in the directory (including attributes and hidden files)
[root@www ~]# ls -al ~
cd (change directory)
cd is the abbreviation of Change Directory , which is a command used to change the working directory.
grammar:
cd [相对路径或绝对路径]
test:
# 切换到用户目录下
[root@kuangshen /]# cd home
# 使用 mkdir 命令创建 kuangstudy 目录
[root@kuangshen home]# mkdir kuangstudy
# 进入 kuangstudy 目录
[root@kuangshen home]# cd kuangstudy
# 回到上一级
[root@kuangshen kuangstudy]# cd ..
# 回到根目录
[root@kuangshen kuangstudy]# cd /
# 表示回到自己的家目录，亦即是 /root 这个目录
[root@kuangshen kuangstudy]# cd ~
Next, you should be able to understand the cd command well after a few more operations.
pwd (display the current directory)
pwd is the abbreviation of Print Working Directory , which is the command to display the current directory.
[root@kuangshen kuangstudy]#pwd [-P]
Options and parameters: -P : Display the actual path instead of using the link path.
test:
# 单纯显示出目前的工作目录
[root@kuangshen ~]# pwd
/root
# 如果是链接，要显示真实地址，可以使用 -P参数
[root@kuangshen /]# cd bin
[root@kuangshen bin]# pwd -P
/usr/bin
mkdir (create a new directory)
If you want to create a new directory, then use mkdir (make directory).
mkdir [-mp] 目录名称
Options and parameters:
- -m: Permission of configuration file! Direct configuration, no need to look at the face of the default permission (umask)~
- -p: Help you directly create the required directory (including the upper directory) recursively!
test:
# 进入我们用户目录下
[root@kuangshen /]# cd /home
# 创建一个 test 文件夹
[root@kuangshen home]# mkdir test
# 创建多层级目录
[root@kuangshen home]# mkdir test1/test2/test3/test4
mkdir: cannot create directory ‘test1/test2/test3/test4’:
No such file or directory # <== 没办法直接创建此目录啊！
# 加了这个 -p 的选项，可以自行帮你创建多层目录！
[root@kuangshen home]# mkdir -p test1/test2/test3/test4
# 创建权限为 rwx--x--x 的目录。
[root@kuangshen home]# mkdir -m 711 test2
[root@kuangshen home]# ls -l
drwxr-xr-x 2 root root 4096 Mar 12 21:55 test
drwxr-xr-x 3 root root 4096 Mar 12 21:56 test1
drwx--x--x 2 root root 4096 Mar 12 21:58 test2
rmdir (can only delete empty directories)
grammar:
rmdir [-p] 目录名称
Options and parameters: **-p: ** Delete along with the upper level "empty" directory
test:
# 看看有多少目录存在？
[root@kuangshen home]# ls -l
drwxr-xr-x 2 root root 4096 Mar 12 21:55 test
drwxr-xr-x 3 root root 4096 Mar 12 21:56 test1
drwx--x--x 2 root root 4096 Mar 12 21:58 test2
# 可直接删除掉，没问题
[root@kuangshen home]# rmdir test
# 因为尚有内容，所以无法删除！
[root@kuangshen home]# rmdir test1
rmdir: failed to remove ‘test1’: Directory not empty
# 利用 -p 这个选项，立刻就可以将 test1/test2/test3/test4 依次删除。
[root@kuangshen home]# rmdir -p test1/test2/test3/test4
Note: This rmdir can only delete empty directories, you can use the rm command to delete non-empty directories, we will later!
cp (copy file or directory)
grammar:
[root@www ~]# cp [-adfilprsu] 来源档(source) 目标档(destination)
[root@www ~]# cp [options] source1 source2 source3 .... directory
Options and parameters:
- **-a: ** Equivalent to the meaning of -pdr, as for pdr, please refer to the following instructions; (commonly used)
- **-p: ** Copy together with the attributes of the file instead of using the default attributes (used for backup);
- **-d: ** If the source file is a link file, copy the link file attributes instead of the file itself;
- **-r: ** Recursive continuous copy, used for directory copy behavior; (commonly used)
- **-f: ** means force. If the target file already exists and cannot be opened, remove it and try again;
- **-i: ** If the destination file (destination) already exists, the action will be asked first when overwriting (commonly used)
- **-l: ** Create a hard link link file instead of copying the file itself.
- **-s: ** Copy into a symbolic link (symbolic link), which is a "shortcut" file;
- **-u: ** Only upgrade the destination if the destination is older than the source!
test:
# 找一个有文件的目录，我这里找到 root目录
[root@kuangshen home]# cd /root
[root@kuangshen ~]# ls
install.sh
[root@kuangshen ~]# cd /home
# 复制 root目录下的install.sh 到 home目录下
[root@kuangshen home]# cp /root/install.sh /home
[root@kuangshen home]# ls
install.sh
# 再次复制，加上-i参数，增加覆盖询问？
[root@kuangshen home]# cp -i /root/install.sh /home
cp: overwrite ‘/home/install.sh’? y #如果文件重复，n不覆盖，y为覆盖
rm (remove files or directories)
grammar:
rm [-fir] 文件或目录
Options and parameters:
- -f: means force, ignore files that do not exist, and no warning message will appear;
- -i: Interactive mode, the user will be asked whether to act before deleting
- -r: delete recursively! The most commonly used in the deletion of the directory! This is a very dangerous option! ! !
test:
# 将刚刚在 cp 的实例中创建的 install.sh删除掉！
[root@kuangshen home]# rm -i install.sh
rm: remove regular file ‘install.sh’? y
# 如果加上 -i 的选项就会主动询问喔，避免你删除到错误的档名！
#rm -rf / #尽量不要在服务器上使用，系统中所有的文件都会被删除，删库跑路就是这么操作的！
mv (Move files and directories, or modify names)
grammar:
[root@www ~]# mv [-fiu] source destination
[root@www ~]# mv [options] source1 source2 source3 .... directory
Options and parameters:
- -f: Force means that if the target file already exists, it will be overwritten without asking;
- -i: If the destination file already exists, it will ask whether to overwrite it!
- -u: If the target file already exists and the source is relatively new, it will be updated (update)
test:
# 复制一个文件到当前目录
[root@kuangshen home]# cp /root/install.sh /home
# 创建一个文件夹 test
[root@kuangshen home]# mkdir test
# 将复制过来的文件移动到我们创建的目录，并查看
[root@kuangshen home]# mv install.sh test #移动文件
[root@kuangshen home]# ls
test
[root@kuangshen home]# cd test
[root@kuangshen test]# ls
install.sh
# 将文件夹重命名，然后再次查看！
[root@kuangshen test]# cd ..
[root@kuangshen home]# mv test mvtest #重命名
[root@kuangshen home]# ls
mvtest