Shell – How to get a help message for zsh builtin’s

command linedocumentationshell-builtinzsh

If I want to get a brief usage message for a bash builtin, I can use help <builtin> at a command prompt, e.g.

$ help export
export: export [-fn] [name[=value] ...] or export -p
    Set export attribute for shell variables.

    Marks each NAME for automatic export to the environment of subsequently
    executed commands.  If VALUE is supplied, assign VALUE before exporting.

    Options:
      -f        refer to shell functions
      -n        remove the export property from each NAME
      -p        display a list of all exported variables and functions

    An argument of `--' disables further option processing.

    Exit Status:
    Returns success unless an invalid option is given or NAME is invalid.

How can I do this in zsh? I've tried

% export --help
zsh: bad option: -e

and 

% help export
zsh: command not found: help

Also the word "help" isn't anywhere in man zshbuiltins.

Best Answer

thanks to @don_crissti linking through this Arch wiki documentation.
For some reason the code on the Arch wiki causes this error on invocation

/home/velour/.zshrc:unalias:368: no such hash table element: run-help

zsh --version => zsh 5.1.1 (x86_64-ubuntu-linux-gnu)

so to get it to work, I added the below block to ~/.zshrc, then commented out the alias commands.

autoload -Uz run-help
autoload -Uz run-help-git
autoload -Uz run-help-svn
autoload -Uz run-help-svk
#unalias run-help
#alias help=run-help

and simply invoke with

run-help <builtin>

So now I get 

% run-help export

export [ name[=value] ... ]
       The specified names are marked for automatic export to the envi-
       ronment  of subsequently executed commands.  Equivalent to type-
       set -gx.  If a parameter specified does not already exist, it is
       created in the global scope.
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