re: [MacPerl-WebCGI] A v B = ?

[email protected] Fri, 9 Mar 2001 12:39:21 +0900
Newsgroups	perl.macperl.webcgi
Message-ID	<v04011701b6cdd3ee300f@[211.132.153.175]>
[email protected] wrote:
>Even placing just the -w on the shebang line causes an Internal Server Error.
which means there's something fundamentally wrong with the code - it won't
compile

>--- start of error.....  aborted due to compilation errors .....--- end of
>error

This is telling you the same thing - there's something fundamentally wrong
with the script so it can't compile

>>[shell prompt]$ tail  /path/to/server/error_logs
>Wish I could, but it's not my server -- I only "rent" space.
Not having access to the error logs is unusual:
 if you can FTP into your account try using a telnet client to log on with
the same connection data you use for FTP.

If you _really_ can't access the server logs, you can re-direct  STDERROR
to STDOUT

<<quoting from  Debugging CGI Scripts 101
( http://www.liquidsilver.com/scripts/debug101.html#server )
Redirect STDERR to STDOUT:

open (STDERR, ">&STDOUT");
I recommend to use this only for debugging, don't leave this in your public
script. Not only are other people likely to get confused when being
confronted with Perl's error messages or warnings but also you won't be
able to track down those errors  in the server's errorlog - that can really
be fatal, imagine your perfectly fine script breaks one day due to a
changed environment or changed permissions of some files and you don't
notice it until weeks later after finally some visitor complained.
end>>

>>.. using '-w' switch, use strict;........
>Okay, I'll remember that when I'm running the code on my Mac.

==Run this to fix errors :-)==
#! perl-w
use strict;
my ($bad_habit,$good_habit,$salvation);

# how to turn bad programming habits
# into good ones

$bad_habit="I\'ll remember that when I\'m running the code on my Mac\n";

&road_to_damascus($bad_habit);

sub road_to_damascus{
		my($revelation);
		$good_habit="I\'ll read the docs\n";
		split('on',$bad_habit);
		$revelation=\@_;
		$$revelation[0]=~ s/the/any/;
		$salvation=join('and ',$$revelation[0],$good_habit);
		print $salvation,"\n";
};
==Run this to fix errors :-)==


>However, I still don't understand why the code I listed in my original
>post didn't work -- it
>didn't fail and it didn't error
An explosion in an airless space is silent, but this doesn't mean the
explosion didn't happen, you just didn't hear it.

>I'm not sure that an error routine would tell me where it went wrong.
It helps eliminate probable causes- this is your script B with some slight
changes -  why does it work? How did I figure out where it was going wrong?


==Script B==
#!/usr/bin/perl-w
use strict;
my (@data);
my ($title,$list);

	print "Content-type: text/html\n\n";
	print "<HTML><HEAD><TITLE>$title</TITLE>";

 # create table with title
	print <<DB;
	<table border="1" cellpadding="5" cellspacing="2" width="600">
	<TR>
	<TH>ID</TH>
	<TH>Category</TH>
	<TH>Variable Name</TH>
	<TH>Price</TH>
	<TH>Name</TH>
	<TH>Description</TH>
	<TH>Item Number</TH>
	</TR>
DB

#$datafile = "Database/outlet.data";
#open (DATA, "$datafile") or die "Can't open $datafile: $!";
	while (<DATA>)
  		{
		next if /^$/;  # skip empty lines
		#chomp;         # remove the "line ending"
		#for (split(/\r/)) # find returns
			{
			# find tabs
			@data= split(/\t/);
			&row;
			}
		}

close DATA;

print "	</table>";

sub row {
 # place variables into table

$list =<<"	ROW";
	<TR>
	<TD>$data[0]</TD>
	<TD>$data[1]</TD>
	<TD>$data[2]</TD>
	<TD>\$$data[3]</TD>
	<TD>$data[4]</TD>
	<TD>$data[5]</TD>
	<TD>$data[6]</TD>
	</TR>

	ROW
print $list;
}


__DATA__
database_id1	category1	variable_name1	price1	description1
	item_number1
database_id2	category2	variable_name2	price2	description2
	item_number2
database_id3	category3	variable_name3	price3	description3
	item_number3
database_id4	category4	variable_name4	price4	description4
	item_number4
==Script B==