How do external commands differ?

External commands differ from shell builtins in several key ways:

1. Execution Context:

   • External Commands: Run as separate processes. The shell creates a new process to execute the command.
   • Shell Builtins: Executed directly within the shell without creating a new process.

2. Speed:

   • External Commands: Generally slower due to the overhead of process creation.
   • Shell Builtins: Faster since they are executed in the current shell environment.

3. Environment Interaction:

   • External Commands: Limited ability to directly manipulate the shell's environment (e.g., changing the current directory).
   • Shell Builtins: Can directly affect the shell's state and environment (e.g., cd changes the current directory).

4. Location:

   • External Commands: Stored as executable files in the file system (e.g., /bin, /usr/bin).
   • Shell Builtins: Integrated into the shell itself.

5. Examples:

   • External Commands: ls, grep, cp, mv.
   • Shell Builtins: cd, echo, exit, history.

If you have more questions or need further clarification, feel free to ask!