help

Overview

The help command displays information about shell (bash) built-in commands. It provides quick reference documentation for commands that are part of the shell itself.

Syntax

help [-dms] [pattern ...]

Common Options

Option Description
-d Output short description
-m Display usage in pseudo-manpage format
-s Output only brief syntax
-i Output detailed information
pattern Show help for commands matching pattern

Key Use Cases

  1. Get help on shell builtins
  2. Check command syntax
  3. View command options
  4. Learn about shell features
  5. Quick reference guide

Examples with Explanations

Example 1: Basic Help

help cd

Show help for cd builtin command

Example 2: Brief Syntax

help -s read

Show only syntax for read command

Example 3: Detailed Information

help -i test

Show detailed information about test command

Understanding Output

Help output includes: - Command syntax - Description - Options - Arguments - Examples - Related commands

Common Usage Patterns

  1. List all builtins:

    help

  2. Get command syntax:

    help -s command

  3. Search for command:

    help command | grep keyword

Performance Analysis

  • Instant access to documentation
  • No external files needed
  • Shell-specific information
  • Memory efficient
  • Always available

Additional Resources