How can I control the Perl call stack?

Question

I am using ActivePerl 5.8 on Windows XP.

use strict;
use warnings;
use Data::Dumper;

There are three routines in my script.

To detect the call stack, I can only insert print "some location";and check the print result from the console window.

Is there any good way to control it? Thanks.

Answer 1

You were not specifically about why you want to keep track of the call stack and keep track of your subtitles, so the answers should be broad.

One method caller:

subscriber

. , , , eval require, undefined .

# 0         1          2
($package, $filename, $line) = caller;

EXPR , . EXPR , .

#  0         1          2      3            4
  ($package, $filename, $line, $subroutine, $hasargs,
#  5          6          7            8       9         10
$wantarray, $evaltext, $is_require, $hints, $bitmask, $hinthash)
 = caller($i);

Devel:: Cover:

, , . B. , , .

, , !

Answer 2

, :

Carp::cluck( "And here the stack:" );

. Carp::cluck. . printf.

Answer 3

T.

:

$ perl -d -e'
sub foo {}
sub bar { foo; }
bar;
'

Loading DB routines from perl5db.pl version 1.32
Editor support available.

Enter h or `h h' for help, or `man perldebug' for more help.

main::(-e:4):   bar;
  DB<1> s
main::bar(-e:3):        sub bar { foo; }
  DB<1> s
main::foo(-e:2):        sub foo {}
  DB<1> T
. = main::foo() called from -e line 3
. = main::bar() called from -e line 4
  DB<1> s
Debugged program terminated.  Use q to quit or R to restart,
  use o inhibit_exit to avoid stopping after program termination,
  h q, h R or h o to get additional info.
  DB<1> q

Answer 4

Perl. caller, , . .

Most often, I want to see the stack trace during debugging. Good news, it's easy to get a stack trace, just use Carp confess and cluckinstead of dieand warn.

use strict;
use warnings;
use Carp;

bar(6.1);
bar(1);

sub foo {
    confess "Oh noes" unless @_ == 6;  # confess is fatal
}

sub bar {
    my $count = shift;
    cluck "bar is in trouble" unless int $count == $count;  # cluck is not fatal
    foo( ('a')x $count );
}

This will help you:

dao:~ toad$ perl test.pl
bar is in trouble at test.pl line 14
    main::bar(6.1) called at test.pl line 5
Oh noes at test.pl line 9
    main::foo('a') called at test.pl line 15
    main::bar(1) called at test.pl line 6