Section A.4. Automatic Variables

A.4. Automatic Variables

The shell defines a number of automatic variables that have special meaning depending on their context within the shell (see Table A-9). See the help about_automatic_variables page for an exhaustive list.

Table A-9. Automatic variables

Variable	Value
$?	Success/fail status of the previous operation
$_	Contains the current pipeline object
$^	Contains the first token of the last line received by the shell
$$	Contains the last token of the last line received by the shell
$args	Contains the set of command-line options passed to a function, filter, or script after any named parameters are consumed
$input	Contains an enumerator of objects entering a function from the pipeline
$lastexitcode	The error level return from the last external command
$error	Array of errors (first element is the most recent)
$null	Null
$true	Boolean true value
$false	Boolean false value