Sticky Bit

The sticky bit is a special permission in Unix-like operating systems, including Linux, that can be set on directories to control user deletion privileges. When the sticky bit is set on a directory, only the directory’s owner, the file’s owner, or the root user can delete or rename files within that directory, even if other users have write permissions.

Key Points:

• Usage: The sticky bit is commonly used on shared directories, such as /tmp, where multiple users have write access. It prevents users from accidentally or maliciously deleting or renaming each other’s files.
• Setting the Sticky Bit:
• Command: You can set the sticky bit using the chmod command.
• Syntax:
  bash chmod +t /path/to/directory
• Example: chmod +t /tmp This command ensures that only the owner of a file in /tmp can delete or rename it.
• Checking the Sticky Bit:
• You can check if the sticky bit is set by listing the directory with ls -ld. A t at the end of the permissions string indicates the sticky bit is set.
• Example:
  bash ls -ld /tmp
  Output might look like:
  drwxrwxrwt 10 root root 4096 Aug 19 12:34 /tmp
  The t in drwxrwxrwt shows that the sticky bit is set.

Example Scenario:

• /tmp Directory: The /tmp directory is a classic example where the sticky bit is typically set. Multiple users can create files in /tmp, but thanks to the sticky bit, only the owner of a file can delete or rename it, ensuring users cannot tamper with each other’s files.

The sticky bit is a simple yet effective way to add an extra layer of security in environments with shared directories.