Perl Programming Language :: Why put a debug option in a production code perl script?


	Why put a debug option in a production code perl script? In the following perl script snippet, the author has a debug option sub main() { my $dir; error ("LANG is $ENV{LANG} -- UTF is no good, man!") if ($ENV{LANG} && $ENV{LANG} =~ m/utf/i); while ($_ = $ARGV[0]) { shift @ARGV; if ($_ eq "--verbose") { $verbose++; } elsif ($_ eq "--debug") { $debug_p++; } elsif (m/^-v+$/) { $verbose += length($_)-1; } elsif (m/^-./) { usage; } elsif (!defined($dir)) { $dir = $_; } else { usage; } } usage unless $dir; $dir =~ s@/+$@@; if (! -d $dir) { print STDERR "$progname: directory $dir does not exist\n"; usage; } build_index $dir; } main(); exit 0; What's the point of shoving a debug option into a script that is supposed to be used by other users? grocery_stocker <cdal@gmail.com> wrote: > In the following perl script snippet, the author has a debug option ... > What's the point of shoving a debug option into a script that is > supposed to be used by other users? You think that stuff that is supposed to be used by other users has no need to be debugged? Xho -- -------------------- http://NewsReader.Com/ -------------------- Usenet Newsgroup Service $9.95/Month 30GB >>>>> "gs" == grocery stocker <cdal@gmail.com> writes: gs> In the following perl script snippet, the author has a debug option forget about the debug option, the code is nutso! gs> sub main() { don't use prototypes, especially for no reason. gs> my $dir; gs> while ($_ = $ARGV[0]) { gs> shift @ARGV; what a wacky way to loop over @ARGV. ever heard of foreach ( @ARGV )?? and his loop fails if ARGV has a '' or 0 value. gs> if ($_ eq "--verbose") { $verbose++; } gs> elsif ($_ eq "--debug") { $debug_p++; } gs> elsif (m/^-v+$/) { $verbose += length($_)-1; } gs> elsif (m/^-./) { usage; } gs> elsif (!defined($dir)) { $dir = $_; } gs> else { usage; } ewww. not much more i can say about that. gs> What's the point of shoving a debug option into a script that is gs> supposed to be used by other users? it would be harder to maintain 2 versions of the code, with/without debugging options. if the real debug code isn't in the way or slows down the program, this little debug option is not a problem. uri -- Uri Guttman ------ u@stemsystems.com -------- http://www.stemsystems.com --Perl Consulting, Stem Development, Systems Architecture, Design and Coding- Search or Offer Perl Jobs ---------------------------- http://jobs.perl.org On May 24, 1:15 pm, xhos@gmail.com wrote: > grocery_stocker <cdal@gmail.com> wrote: > > In the following perl script snippet, the author has a debug option > ... > > What's the point of shoving a debug option into a script that is > > supposed to be used by other users? > You think that stuff that is supposed to be used by other users has no > need to be debugged? It hurts to think somedays. Today is one of those days. grocery_stocker wrote: > In the following perl script snippet, the author has a debug option [snip] > while ($_ = $ARGV[0]) { > shift @ARGV; > if ($_ eq "--verbose") { $verbose++; } > elsif ($_ eq "--debug") { $debug_p++; } > elsif (m/^-v+$/) { $verbose += length($_)-1; } > elsif (m/^-./) { usage; } > elsif (!defined($dir)) { $dir = $_; } > else { usage; } > } [snip] On a side note to what others have said, it would be better to use Getopt::Long vs. looping through @ARGV. -- Len grocery_stocker wrote: > In the following perl script snippet, the author has a debug option [ ... ] > What's the point of shoving a debug option into a script that is > supposed to be used by other users? Sometimes people complain that they have this or that problem when using my code. I'd have several problems, then: 1. I'd have to spend additional time to produce a debuggable version 2. I may not be able to (re-)produce the exact version that person has (this can most often be achieved by using a versioning system that's worth its name, not everybody does that (blush)) 3. The introduction of debugging code might change the behaviour of the code and/or may even require some code to be rewritten to accomodate the debugging code (a veryvery simple example might be when you directly return a complicated expression and want to print out its value beforehand) There are probably lots of reasons I can't think of. So I can just tell them "retry with a -d option, redirect stdout into a file, then send me that file". MHO, Josef -- These are my personal views and not those of Fujitsu Siemens Computers! Josef Mllers (Pinguinpfleger bei FSC) If failure had no penalty success would not be a prize (T. Pratchett) Company Details: http://www.fujitsu-siemens.com/imprint.html