Rather than using a debugger, I prefer to put lots of print() statements
in my code, showing where the execution has got to, values of variables,
and so on. I have written a module to help with this, at the moment
it's called Dbg but obviously I need to pick a better name.
An example may demonstrate why a module is useful for this, rather than
just typing out print statements:
use Dbg qw(t d);
$Dbg::On = 1; # global flag turning print statements on or off
$Dbg::As_HTML = 1; # HTML-ify all messages, since this is a CGI script
t('starting');
# Tracing complex data structures with Data::Dumper
my $v = [ 'a', 'b', { } ];
t('variable $v has value ' . d($v));
sub foo {
# This subroutine has already been debugged. I'll turn off trace
# messages here.
#
local $Dbg::On = 0;
# do some stuff including lots of trace statements, which don't need
# to be commented out
#
}
The module provides an easy way to turn trace on and off for particular
sections of code (rather than having to comment and uncomment trace
lines in an editor). The subroutine names 't' and 'd' are a bit
cryptic, but something called so freqently (sometimes every other line
of code) needs a short name. They aren't exported without asking.
I've looked for an existing module which does something similar. The
Devel:: modules seem to be focussed on peeking into perl's guts, while
the Log:: modules are much more complex, and 'logging' is different to
'debugging trace messages'. (Logfiles are seen by the user, whereas
trace messages are to help the developer and are turned off in the
released version.)
So I don't think that a Log:: prefix makes sense, and although the
module is there to help developers, it doesn't fit in with the other
Devel:: modules. None of the other categories in the module list seems
to fit. The best I've come up with so far is Devel::Print or
Log::TraceMessages. Suggestions?
--
Ed Avis
[EMAIL PROTECTED]
