Bash Getting started with Bash Viewing information for Bash built-ins


Example

help <command>

This will display the Bash help (manual) page for the specified built-in.

For example, help unset will show:

unset: unset [-f] [-v] [-n] [name ...]
   Unset values and attributes of shell variables and functions.

   For each NAME, remove the corresponding variable or function.

   Options:
     -f    treat each NAME as a shell function
     -v    treat each NAME as a shell variable
     -n    treat each NAME as a name reference and unset the variable itself
       rather than the variable it references

   Without options, unset first tries to unset a variable, and if that fails,
   tries to unset a function.

   Some variables cannot be unset; also see `readonly'.

   Exit Status:
   Returns success unless an invalid option is given or a NAME is read-only.

To see a list of all built-ins with a short description, use

help -d