What are some common chmod commands?

What are some common chmod commands I should know?

Common chmod commands include:

1. chmod 755 filename - gives read, write, and execute permissions to the owner, and read and execute to others.
2. chmod 644 filename - gives read and write permissions to the owner, and read-only to others.
3. chmod 700 filename - gives all permissions to the owner and none to others.

What does the number in chmod mean?

The number in chmod represents permissions in octal format. Each digit corresponds to a different set of users: owner, group, and others. For example, 7 means read (4), write (2), and execute (1) permissions combined.

Can I use letters instead of numbers?

Yes, you can use letters! For example, chmod u+x filename adds execute permission for the user (owner). You can also use g for group and o for others.

What happens if I set permissions to 000?

Setting permissions to 000 means no one can read, write, or execute the file, effectively making it inaccessible.