Linux Shell: Rm, ls, grep

Under the current path

Ls-altr

Space and sky are both folders, and the rest are files. The directory structure is as follows:

1. List all folders in the current path

Ls-L | grep ^ d

2. count the number of folders in the current path

Ls-L | grep ^ d | WC-l

3. list all files or folders under the current directory except those containing the space keyword?

Ls | grep-V "space"

4. Just want to keep the file or folder containing the space keyword?

Rm-fr 'ls | grep-V "space "'

Check the current directory again:

5. Only space.txt is retained?

Rm-fr 'ls | grep-V "space.txt $ "'

Note:

''Is the symbol corresponding to the ESC button on the keyboard.