Returns the context of the current subroutine call. In scalar context, returns the caller's package name if there is a caller, that is, if we're in a subroutine or
require(), and the undefined value otherwise. In list context, returns
($package, $filename, $line) = caller;
With EXPR, it returns some extra information that the debugger uses to print a stack trace. The value of EXPR indicates how many call frames to go back before the current one.
($package, $filename, $line, $subroutine, $hasargs, $wantarray, $evaltext, $is_require) = caller($i);
$subroutine may be
"(eval)" if the frame is not a subroutine call, but an
eval(). In such a case additional elements
$is_require are set:
$is_require is true if the frame is created by a
$evaltext contains the text of the
eval EXPR statement. In particular, for a
eval BLOCK statement,
$evaltext is undefined. (Note also that each
use statement creates a
require frame inside an
eval EXPR) frame.
Furthermore, when called from within the DB package, caller returns more detailed information: it sets the list variable
@DB::args to be the arguments with which the subroutine was invoked.
Be aware that the optimizer might have optimized call frames away before
caller() had a chance to get the information. That means that
caller(N) might not return information about the call frame you expect it do, for
N > 1. In particular,
@DB::args might have information from the previous time
caller() was called.