Main Options
Combine various options of the `chmod` command to set permissions for files and directories.
1. Permission Setting Methods
2. Additional Options
Generated command:
Try combining the commands.
Description:
`chmod` Executes the command.
Combine the above options to virtually execute commands with AI.
Understanding Permissions
Linux file permissions consist of Read, Write, and Execute rights for the owner (User), group (Group), and others (Others). These combinations can be expressed as octal numbers or symbolic characters.
Octal Permission Values
Each permission can be expressed numerically, and the sum defines permissions for owner, group, and others, forming a 3-digit octal mode.
- 4: Read (r)
- 2: Write (w)
- 1: Execute (x)
- 0: No Permission (-)
Understanding Symbolic Mode
Symbolic mode modifies permissions using 'target (u:user, g:group, o:others, a:all) + operator (+:add, -:remove, =:set) + permission (r,w,x)'. For example, `u+x` adds execute permission to the user, and `go=rw` sets read/write for group and others.
| Mode | Description | Symbolic |
|---|---|---|
| 777 | All permissions (read, write, execute) for everyone | rwxrwxrwx |
| 755 | Owner: all, Group/Others: read/execute | rwxr-xr-x |
| 644 | Owner: read/write, Group/Others: read-only | rw-r--r-- |
| 600 | Owner: read/write, Group/Others: none | rw------- |
Examples
Practice setting permissions with real-world examples of the `chmod` command.
Owner-only read/write (600)
chmod 600 myfile.txtRestricts access to others; only the owner can read/write. One of the most secure permission settings.
Add execute permission to a script
chmod +x myscript.shMakes a script executable by all users. Useful for web server scripts, etc.
Recursively set directory and subfiles (755)
chmod -R 755 mydir/Apply 755 permissions recursively to a directory and its contents. Useful for static web content directories.
Remove write permission from group/others
chmod go-w important_file.confRemoves write access from group and others. Enhances security.