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It seems that I haven't understood properly the perldocs of the caller function. My understanding was that with caller(1), I walk up one frame (i.e. get the information about who is calling me), with caller(2) I walk up 2 frames, etc.

But now look at the following example program. _format_caller is called twice; the first time it is supposed to print what is returned by caller(1), the second time caller(2).

use strict; use warnings; sub _format_caller { my @x=caller($_[0]); print "elements:",scalar(@x),"\n"; print(join(',',@x),"\n"); } sub f { my $level=$_[0]; print "test caller $level\n"; _format_caller($level); } f(1); f(2);
The actual printout looks like this:
> Use of uninitialized value in join or string at U:\develsv\ARTS\playgr +ound\ line 7. Use of uninitialized value in join or string at U:\develsv\ARTS\playgr +ound\ line 7. Use of uninitialized value in join or string at U:\develsv\ARTS\playgr +ound\ line 7. test caller 1 elements:10 main,U:\develsv\ARTS\playground\,16,main::f,1,,,,2,UUUUUU +UUUUU test caller 2 elements:0
Well, the uninitialized warnings are because some of the elements returned by caller are undef. But why don't I get anything back in the case of caller(2)?

Ronald Fischer <>

In reply to caller() mystery by rovf

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