Ch2. Manage Files from the Command Line
The File-system Hierarchy:
Absolute paths and Relative paths:
-For standard Linux file systems, the path name of a file, including all / characters, may be no more than 4095 bytes long.
-Each component of the path name separated by / characters may be no more than 255 bytes long.
[root@master Desktop]# cd
[root@master ~]# cd /root/Videos
[root@master ~]# cd Videos
[root@master ~]# pwd
[root@master Videos]# cd /root/Documents
[root@master ~]# cd ~abeer (go to the home directory of the user)
[root@master abeer]# cd - (go to the previous directory)
[root@master abeer]# cd .. (up one level)
[root@master abeer]# cd ../.. (up two levels)
list files:
[root@master ~]# ls
[root@master ~]# ls -l ~ (long list)
[root@master ~]# ls -a (all files and directories including hidden ones)
[root@master ~]# ls -la
[root@master ~]# ls -lh (human readable)
[root@master ~]# ls -R (Recursive)
[root@master ~]# ls -t (access time)
[root@master ~]# ls -r (reverse order)
[root@master ~]# dir
[root@master ~]# dir --color
Creating files:
[root@master ~]# touch file1 FILE1 (case sensitive)
[root@master ~]# touch /root/Documents/file
[root@master ~]# ls -R
- If the file exist, it will reset the timestamp of the file.
Create directories:
[root@master ~]# mkdir dir1 dir2 dir3
[root@master ~]# mkdir -p dir4/dir5
[root@master ~]# mkdir 'abeer hosni'
[root@master ~]# mkdir "abeer hosni"
[root@master ~]# mkdir abeer\\ hosni
Copy files and directories:
[root@master ~]# cp file1 file2 (creates file2)
[root@master ~]# cp file1 /root/Documents/
[root@master ~]# cp file1 file2 file3 /root/Documents/ (last argument must be a directory)
[root@master ~]# cp -r /etc/ dir1 (copy non-empty directory)
[root@master ~]# cp -r /etc/* dir1 (copy the contents of he directory)
[root@master Documents]# cp ~/file1 .
Move files and directories:
[root@master ~]# mv file1 new_file1 (to rename the file1)
[root@master ~]# mv file1 file2 file3 /root/Documents/ (last argument must be a directory)
[root@master ~]# mv dir1 dir2 dir3 dir4 (last argument must be a directory)
Remove files and directories:
[root@master ~]# rm file1 (interactive by default for the root)
[root@master ~]# rm -f file1 file2 file3 (force remove)
[root@master ~]# rm -d dir1 (removes an empty directory)
[root@master ~]# rmdir dir1 (removes an empty directory)
[root@master ~]# rm -rf dir1 (removes a non-empty directory)
Nautilus:
[root@master ~]# nautilus
[root@master ~]# nautilus /etc/
File globbing (wildcard) (pattern matching) (path name expansion):
[root@master ~]# touch alfa bravo charlie delta echo able baker cast dog easy
[root@master ~]# ls a* (Only file names beginning with "a")
[root@master ~]# ls *a (Only file names ending with "a")
[root@master ~]# rm -f a*
[root@master ~]# ls *a* (Only file names containing "a")
[root@master ~]# ls [!a]* (Only file names where first character is not "a")
[root@master ~]# ls [ac]*
[root@master ~]# ls ????
[root@master ~]# ls ?????
[root@master ~]# touch file1 file2 file3 file4 file11 file12 file111 filea fileb fileab fa fab fabc
[root@master ~]# ls f?
[root@master ~]# ls f??
[root@master ~]# ls file[a-c]
[root@master ~]# ls file[^a-c]
[root@master ~]# echo ~abeer
Variable, Command and Arithmetic substitution:
Variable substitution:
[root@master ~]# x=5
[root@master ~]# echo x
[root@master ~]# echo $x (The value of variable x)
Command substitution:
[root@master ~]# echo "Today is $(date)"
Arithmatic substitution:
[root@master ~]# echo "Sum of 1 plus 2 is $[1+2]"
[root@master ~]# echo "Sum of 1 plus 2 is $((1+2))"
Others :
Create Symbolic Links
[user@host ~]$ ln -s /home/user/newfile-link2.txt /tmp/newfile-symlink.txt
[user@host ~]$ ls -l newfile-link2.txt /tmp/newfile-symlink.txt
-rw-rw-r--. 1 user user 12 Mar 11 19:19 newfile-link2.txt
lrwxrwxrwx. 1 user user 11 Mar 11 20:59 /tmp/newfile-symlink.txt -> /home/user/newfile-link2.txt
[user@host ~]$ cat /tmp/newfile-symlink.txt
Symbolic Hello World
