chmod and chown explained

View original Gist on GitHub

chmod explained.md

r - Read
w - Write
x - Execute

u - The owner of the file
g - The group that the file belongs to
o - Anybody who is not one of the above
a - All users

+ - Add permissions
- - Remove permissions

Syntax Structure:

chmod <people><+/-><permissions>

Examples:

• chmod o-w: deny others from editing the file
• chmod u+rwx give the owner full control
• chmod +rwx give everyone full control
• chmod +x allow anyone to execute the file

Numericals:

chmod 755

Each number represents a different authorisation point…

• 7: owner
• 5: group
• 5: everyone else

Each item is the total of the following numbers…

• 4: read
• 2: write
• 1: execute

So 755 means…

• 7: read, write and execute for the owner
• 5: read and execute for the group
• 5: read and execute for everyone else

chown explained.sh

chown <user>:<group> <file>