The Perl debuger is a wonderful tool. By setting its warnlevel or dielevel you can get it to print out a stack trace on a warn or a die. But what if you want to breakpoint on those events? This snippet (when put into a ./.perldb or ~/.perldb file) allows you to set breakpoints (after printing the warn/dielevel stack traces, if any) on these events. Just type sow to stop on warn, or sod to stop on die.

update: made it pass args to oldWarn/oldDie

# Stop on warn (sow)
$DB::oldWarn = $SIG{__WARN__};
$DB::alias{sow} = 's/^sow/\$SIG{__WARN__} = sub { \$DB::oldWarn->(@_) 
+if (\$DB::oldWarn); \$DB::single = 1 }/';
# Stop on die (sod)
$DB::oldDie = $SIG{__DIE__};
$DB::alias{sod} = 's/^sod/\$SIG{__DIE__} = sub { \$DB::oldDie->(@_) if
+ (\$DB::oldDie); \$DB::single = 1 }/';

[download]

In reply to Breakpoint on warn or die in the debugger by bikeNomad

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.