chown¶

ls -l ~/z

-rw-rw-r-- 1 milad milad 0 Dec 28 07:19 /home/milad/z

cat /etc/passwd | head -2

root:x:0:0:root:/root:/bin/bash
daemon:x:1:1:daemon:/usr/sbin:/usr/sbin/nologin

sudo chown root ~/z

ls ~/z -l

-rw-rw-r-- 1 root adm 0 Dec 28 07:19 /home/milad/z

sudo chown :root ~/z

ls -l ~/z

-rw-rw-r-- 1 root root 0 Dec 28 07:19 /home/milad/z

sudo chown milad:milad z

ls -l ~/z

-rw-rw-r-- 1 milad milad 0 Dec 28 07:19 /home/milad/z

chmod¶

touch a b c

ls -la a b c

-rw-rw-rw- 1 milad milad 0 Dec 28 10:02 a
-rw-rw-rw- 1 milad milad 0 Dec 28 10:02 b
-rw-rw-rw- 1 milad milad 0 Dec 28 10:02 c

chmod ugo+w [a-c]

ls -la [a-c]

stat -c "%a %n" [a-c]

-rw-rw-rw- 1 milad milad 0 Dec 28 10:02 a
-rw-rw-rw- 1 milad milad 0 Dec 28 10:02 b
-rw-rw-rw- 1 milad milad 0 Dec 28 10:02 c

666 a
666 b
666 c

chmod u+x,o-rw [a-c]

ls -la [a-c]

-rwxrw---- 1 milad milad 0 Dec 28 10:02 a
-rwxrw---- 1 milad milad 0 Dec 28 10:02 b
-rwxrw---- 1 milad milad 0 Dec 28 10:02 c

chmod 067 a

ls -la a

----rw-rwx 1 milad milad 0 Dec 28 10:02 a

chmod u+rw,o-rwx a

ls -la a

-rw-rw---- 1 milad milad 0 Dec 28 10:02 a

The default permissions on

Files: 666 (Because we don't want files to have X by default) Directories: 777 (Because we need X to cd in)

umask
#files 664
#directories 775

0002

mkdir test
stat -c "%a %n" test

775 test

ls -ld /tmp

drwxrwxrwt 11 root root 4096 Dec 28 10:28 /tmp

All lecture notes are available at github in ipynb format: https://github.com/ravexina/linux-notes.

There are html exports of project available at: https://ravexina.github.io/linux-notes.