help (shell builtin)

Updated

September 4, 2026

Overview

help shows documentation for shell builtins — commands implemented inside the shell itself (cd, export, read, [[, declare, job control, etc.), not as separate binaries under /usr/bin. External programs use --help or man instead.

If man cd looks wrong or minimal, you are probably looking at a stub; the real reference is help cd (bash) or the shell’s own manual.

Syntax

help [-dms] [pattern ...]

Bash-oriented options (check help help on your shell):

Option Description
-d Short description only
-m Manpage-like layout
-s Short usage synopsis
pattern Builtin name or pattern to match

Common Options / discovery helpers

Command Description
help List topics / usage overview
help name Full builtin help
type name How the shell resolves name
type -a name All candidates (builtin + PATH)
command -v name Path or builtin indicator
compgen -b List bash builtins
enable -a Enabled/disabled builtins

Examples with Explanations

Read builtin docs

help cd
help [[
help declare
help read
help -m printf          # man-like layout for the builtin printf
help | less             # browse all topics

Builtin vs external

type cd                 # builtin
type ls                 # usually /usr/bin/ls (hashed)
type -a echo            # may show builtin and /usr/bin/echo
type -a kill            # often both: shell kill + /bin/kill
help cd                 # works for builtin
ls --help               # external GNU flag
man ls                  # full external manual

Prefer type / command -v in scripts over which for resolving names.

List builtins (bash)

compgen -b | column
compgen -b | grep -E '^(cd|pushd|popd|dirs)$'
enable -a | head

Disable / re-enable a builtin (rare, debugging)

enable -n echo          # force external echo next
type echo
enable echo             # restore builtin

Useful when testing whether a weird echo behavior comes from the builtin or a shadowed binary.

Conditional help in interactive setups

# only define an alias if the real command exists
if type -P rg >/dev/null; then
  alias grep='rg'
fi

type -P searches PATH only (ignores builtins/aliases/functions).

Job-control and shell language topics

help jobs
help fg
help bg
help wait
help trap
help set
help shopt

These are not separate man pages in the same way; learn them via help + man bash.

Notes / Pitfalls

  • help is primarily for interactive humans. Non-interactive scripts still run builtins; they just don’t need help.
  • zsh uses run-help (often bound to Esc-h) and different docs; fish integrates web/local docs under help.
  • help printf is the shell printf; man 1 printf / man 3 printf are different tools/APIs.
  • Aliases and functions shadow names: type foo before assuming you are reading the right help.
  • BusyBox / dash environments have smaller builtin sets; don’t assume full bash help text.

2026-relevant notes

  • Bash 5.x remains the default interactive shell on many servers; help text tracks your installed bash, not a website.
  • For deep language reference (arrays, coprocs, mapfile, loadable builtins), combine help with man bash / info bash.
  • In containers, shells are often bash or sh → dash; verify with echo $0 and help availability.

Additional Resources