perl5db.pl 1.28: Settings deleted after error

[LanX]

Hi

I'm not sure if it's a bug or a matter of configuration. When I use perl5db.pl as a perl-shell and any error occurs, some special variables and settings get lost. This error is not reproducible with V1.3, but this belongs to Perl 5.10 and I'm not sure if I can safely install this version in conjunction with Perl 5.8.8.

Here an example:

lanx@xubuntu:~$ perl -de0

Loading DB routines from perl5db.pl version 1.28
Editor support available.

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

main::(-e:1):    0
DB<1> $\="XXX"

DB<2> print
XXX
DB<3> print 5/0
Illegal division by zero at (eval 12)[/usr/share/perl/5.8/perl5db.pl:6
+28] line 2.
 at (eval 12)[/usr/share/perl/5.8/perl5db.pl:628] line 2
    eval '($@, $!, $^E, $,, $/, $\\, $^W) = @saved;package main; $^D =
+ $^D | $DB::db_stop;
print 5/0;

;' called at /usr/share/perl/5.8/perl5db.pl line 628
    DB::eval called at /usr/share/perl/5.8/perl5db.pl line 3410
    DB::DB called at -e line 1

DB<4> print

DB<5>

Thanx

- LanX

[Anonymous Monk]

You can't use it as-is, because it uses defined-or ( $var //= 'new'; ), a perl-5.10 feature. Here's a patch to fix that

--- perl5db.pl    2007-12-18 11:38:11.000000000 -0800
+++ perl5dbFOR5.8.pl    2008-10-17 18:00:50.812500000 -0700
@@ -6025,7 +6025,7 @@
 } ## end sub setterm
 
 sub load_hist {
-    $histfile //= option_val("HistFile", undef);
+    $histsize = option_val("HistFile",undef) unless defined $hintsize
+;#patch-5.8 $histfile //= option_val("HistFile", undef);
     return unless defined $histfile;
     open my $fh, "<", $histfile or return;
     local $/ = "\n";
@@ -6043,7 +6043,7 @@
     eval { require File::Basename } or return;
     File::Path::mkpath(File::Basename::dirname($histfile));
     open my $fh, ">", $histfile or die "Could not open '$histfile': $
+!";
-    $histsize //= option_val("HistSize",100);
+    $histsize = option_val("HistSize",100) unless defined $hintsize;#
+patch-5.8 $histsize //= option_val("HistSize",100);
     my @copy = grep { $_ ne '?' } @hist;
     my $start = scalar(@copy) > $histsize ? scalar(@copy)-$histsize :
+ 0;
     for ($start .. $#copy) {

[Anonymous Monk]

Thank you

... wouldn't it be better to contact the author to improve the official release? Or will I get the answer that I'm supposed to install 5.10?

[Anonymous Monk]

perl5db ought to have a

use 5.010000;

statement, aside from that, you will probably get the answer to install 5.10, as perl5db is only distributed with perl.