caller: caller [expr]

Return the context of the current subroutine call.

Without EXPR, returns "$line $filename". With EXPR, returns "$line $subroutine $filename"; this extra information can be used to provide a stack trace.

The value of EXPR indicates how many call frames to go back before the current one; the top frame is frame 0.

Exit Status:
Returns 0 unless the shell is not executing a shell function or EXPR is invalid.