Re: Perl Debugger: setting a breakpoint in another file with 'b'

If you want to stop at a function mod::subname in a not-yet-loaded module, you can use the
b postpone mod::subname [condition] debugger command. It will delay the setting of the breakpoint until the module has been loaded. The filename:linenumber syntax is not available, as far as I know.

So b postpone UsefulModule::do_stuff should work.

This is described in the book "Pro Perl Debugging" from Richard Foley and Andy Lester.

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Re^2: Perl Debugger: setting a breakpoint in another file with 'b' by LanX (Saint) on May 16, 2015 at 10:56 UTC
no book needed :) lanx@lanx-1005HA:~$ perl -de0 Loading DB routines from perl5db.pl version 1.33 Editor support available. Enter h or `h h' for help, or `man perldebug' for more help. main::(-e:1): 0 DB<1> h b b Sets breakpoint on current line) b [line] [condition] Set breakpoint; line defaults to the current execution line; condition breaks if it evaluates to true, defaults to '1'. b subname [condition] Set breakpoint at first line of subroutine. b $var Set breakpoint at first line of subroutine referenced by + $var. b load filename Set breakpoint on 'require'ing the given file. b postpone subname [condition] Set breakpoint at first line of subroutine after it is compiled. b compile subname Stop after the subroutine is compiled. DB<2> [download] see also `perldebug` Cheers Rolf _{(addicted to the Perl Programming Language and ☆☆☆☆ :) Je suis Charlie!}	[reply] [d/l]
Re^3: Perl Debugger: setting a breakpoint in another file with 'b' by Dumu (Monk) on May 18, 2015 at 13:53 UTC
Incidentally, I realised last night that you can even start a Perl debugger REPL using a divide by zero: `perl -de1/0` [download] And it still works (i.e. starts the debugger and puts you into a "Perl shell"), although you do get an 'Illegal division by zero' error if you then execute any of the 'stepping' commands. So I wonder if there is anything you can put after `perl -de` that won't let the debugger start?	[reply] [d/l] [select]
Re^3: Perl Debugger: setting a breakpoint in another file with 'b' by Dumu (Monk) on May 18, 2015 at 13:49 UTC
Danke sehr, Rolf... I had not tried '`b postpone`', only '`b compile`' and '`b load`', which hadn't apparently worked. I shall try '`b postpone`'! It was staring me in the face the whole time.	[reply] [d/l] [select]
Re^2: Perl Debugger: setting a breakpoint in another file with 'b' by Dumu (Monk) on May 18, 2015 at 13:56 UTC
Thanks hexcoder, I shall try to get a copy of that book. I have alredy enjoyed Perl Debugged by Peter Scott and Ed Wright, which is useful despite being a bit of an old book.	[reply]