What are other chmod options?

The chmod command has several options for changing file permissions. Here are some commonly used options:

1. Add Permissions:

   • +r: Add read permission.
   • +w: Add write permission.
   • +x: Add execute permission.

   Example:

   chmod +r file.txt  # Adds read permission to file.txt

2. Remove Permissions:

   • -r: Remove read permission.
   • -w: Remove write permission.
   • -x: Remove execute permission.

   Example:

   chmod -x script.sh  # Removes execute permission from script.sh

3. Set Exact Permissions:
   You can set permissions explicitly using numeric values:

   • 0: No permission
   • 1: Execute
   • 2: Write
   • 4: Read

   You can combine these values for user, group, and others. For example:

   • chmod 755 file.txt: Sets read, write, and execute for the owner, and read and execute for group and others.
   • chmod 644 file.txt: Sets read and write for the owner, and read for group and others.

4. Recursive Change:
   Use the -R option to change permissions recursively for directories and their contents.

   chmod -R 755 directory_name  # Changes permissions for all files and subdirectories

5. Symbolic Mode:
   You can specify permissions using symbolic notation:

   • u: User (owner)
   • g: Group
   • o: Others
   • a: All (user, group, and others)

   Example:

   chmod u+x file.txt  # Adds execute permission for the user
   chmod go-w file.txt  # Removes write permission for group and others

These options allow you to customize file permissions according to your needs.