Re^3: Debugging a program

Thanks, that saves the action of setting a breakpoint.

But even better, I could shift the signal handler code into the debugger initialization file .perldb. Then I do not have to modify the original source code. Works great!

This is the content of file .perldb (place it in the current or in the home directory):

sub afterinit 
{
    $::SIG{'__WARN__'} = sub {
        my $warning = shift;
        if ( $warning =~ m{\s at \s \S+ \s line \s \d+ \. $}xms ) {
            $DB::single = 1;    # debugger stops here automatically
        }
        warn $warning;
    };
    print "sigwarn handler installed!\n";
    return;
}
[download]

Comment on Re^3: Debugging a program Download Code

Replies are listed 'Best First'.
Re^4: Debugging a program by hexcoder (Curate) on Jul 18, 2016 at 11:59 UTC
Addition ... and under Windows save it to file `perldb.ini` in your `%HOMEDRIVE%%HOMEPATH%` directory. Then make sure to set the file attributes to read-only. That way it is safe and the debugger is happy.	[reply] [d/l] [select]
Re^5: Debugging a program by hexcoder (Curate) on Feb 20, 2019 at 12:48 UTC
With Strawberry Perl 5.26.2 (Windows 7) I got some complaints about unknown terminal window size when starting the debugger. `Unable to get Terminal Size. The Win32 GetConsoleScreenBufferInfo call + didn't work. The COLUMNS and LINES environment variables didn't work +. at C:/Strawberry/perl/vendor/lib/Term/ReadLine/readline.pm line 410 +.` [download] These lines in `sub afterinit` take care of it: my ($cols, $lines) = split ' ', (grep { m{^\s*\d+\s+\d+\s}xms } `p +owershell -command "&{\$H=get-host;\$H.ui.rawui.WindowSize;}"`)[0]; $ENV{'COLUMNS'} = $cols; $ENV{'LINES'} = $lines; print "COLUMNS and LINES are set ($cols,$lines).\n"; [download] Powershell is used here to get the console property `WindowSize`. Then the environment variables `COLUMNS` and `LINES` are locally set and the `readline.pm` module is happy.	[reply] [d/l] [select]
Re^6: Debugging a program by jdporter (Paladin) on Feb 20, 2019 at 17:24 UTC
Sweet! I'd prob do it this way: `my( $cols, $lines ) = qx( powershell -command "&{ \$H=get-host; \$H.ui +.rawui.WindowSize.Width; \$H.ui.rawui.WindowSize.Height; }" ) =~ /(\d ++)/g;` [download] I reckon we are the only monastery ever to have a dungeon stuffed with 16,000 zombies.	[reply] [d/l]
Re^6: Debugging a program with Tk by hexcoder (Curate) on Sep 19, 2019 at 09:08 UTC
When using Tk, I observed that my custom debugging signal handler for `$SIG{__WARN__}` is overwritten by Tk :(. So I needed to reoverwrite it after `use Tk;` with my own one again. `use Tk; ... # if running with debugger, reinstall signal handler if (defined $DB::single) { # avoid warning: '$DB::single' is only used once $DB::single = $DB::single; DB::afterinit(); }` [download] Unfortunately this requires modification of the script. Any suggestions for enhancements are welcome.	[reply] [d/l] [select]