1. What Is the Sticky Bit?

The sticky bit is a permission bit that can be set on directories in Unix-like systems. When set on a directory, it restricts file deletion so that only the file owner, directory owner, or root can delete files within it.

2. How Does the Calculator Work?

The calculator uses the sticky bit formula:

Where:

• \( Base\_mode \) — Standard 3-digit octal permissions (e.g., 755, 644)
• 1000 — The sticky bit value in octal notation

Explanation: The sticky bit adds 1000 to the base permission mode in octal notation. This results in a 4-digit mode where the first digit represents special permissions.

3. Importance of Sticky Bit

Details: The sticky bit is commonly used on directories like /tmp to prevent users from deleting files owned by others, while still allowing them to create and modify their own files.

4. Using the Calculator

Tips: Enter the base 3-digit octal permission (e.g., 755, 644). The calculator will add the sticky bit (1000) and show the resulting 4-digit mode.

5. Frequently Asked Questions (FAQ)

Q1: How do I set the sticky bit using chmod?
A: You can use either chmod +t directory or chmod 1777 directory (where 1777 is the sticky bit plus full permissions).

Q2: How can I tell if a directory has the sticky bit set?
A: Use ls -ld directory and look for a 't' or 'T' in the execute bit of others permissions (e.g., drwxrwxrwt).

Q3: What's the difference between 't' and 'T' in ls output?
A: 't' means sticky bit is set and execute is set for others. 'T' means sticky bit is set but execute is not set for others.

Q4: Can I set sticky bit on files?
A: While technically possible, it has no effect on modern Unix systems. It's only meaningful for directories.

Q5: What are other special permission bits?
A: The setuid bit (4000) and setgid bit (2000) are other special permissions that can be combined with the sticky bit.