builtin help unset

[shoebill]

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.