Como set
e unset
são internos do shell, você precisa usar o comando help
para obter ajuda detalhada:
$ help unset
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.