Strange file handling - please help
in [Perl]
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From: Steve M on 22 Apr 2010 15:36 On 4/22/2010 10:29 AM, John wrote: > J�rgen Exner<jurgenex(a)hotmail.com> wrote: > >> John<John.Smith(a)invalid.com> wrote: >>> I have a text file test.txt: >>> <style> >>> a {font-size: 12px;font-family: Arial,Helvetica,sans-serif;} >>> </style> >>> >>> I want to print the file with the following Perl program: >>> >>> #!/usr/bin/perl >> >> You are missing >> use strict; use warnings; >> >>> print "Content-Type: text/html; charset=iso-8859-1\n\n"; >>> print '<html><head>'; >>> print '<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">'; >>> print '</head> <BODY>'; >>> open MYFILE,"<test.txt"; >> >> Nowadays the three-argument form of open using a lexical file handle is >> the preferred method of opening a file. >> >>> $ii=1; >> >> If you want the line number then you can use the predefined variable $. > > Please explain? I am giving variable $ii the value on one (number 1). > $. is the INPUT_LINE_NUMBER > >> >>> while ($myline=<MYFILE>) >>> { >>> print "The value is now $ii<br>"; # I expect to see "1" --> OK! >>> print "Line : ".$myline." was here<br>"; # I get "Line : was here" >> >> Cannot reproduce your result (This is perl, v5.10.1 built for >> MSWin32-x64-multi-thread). I am getting >> >> Line :<style> >> was here<br> >> >> and subsequenlty corresponding results for the other two lines. >> >>> print "Now it is $ii<br>"; # I get "Now it is 3 >> >> I am getting >> >> Now it is 1<br> >> >> during the first iteration and >> >> Now it is 3<br> >> >> during the last iteration, just as I would have expected. >> >>> $ii=$ii+1; >>> } >>> close MYFILE; >>> print "</body> </HTML>"; >> >> jue > > > If $ii has the value of one shouldn't it be 2 after $ii=$ii+1 ? > I've also tried $ii++; and still get 3 > > > I do get correct operaton with a a diffent text file (the quick brown fox .. > version). I checked both text files and they bothe were ANSI with carriage+line > feed endings. Given the above you are banging on a simple cgi script and viewing the output in a browser which makes this more of a CGI issue than a Perl issue, but: If you view the source you should see the the text you expect to see is in fact in the source, but given that it is wrapped in the <style> tags your browser is not displaying it. The final line with '3' in it shows up because it is outside the closing </style> tag. Firebug is (or should be) your friend if you are going to do CGI work. Get it. Learn it. Love it. Firebug is a CGI/Javascript/AJAX developers absolute *must have* plugin for FireFox. Your mention of the cr/lf endings AND the shebang line used suggest you are pretty new at cross-platform CGI work. Placing the <style> where you did (inside the <body>) is very suggestive of your relative HTML knowledge. I'm thinking you might need to brush up on CGI in general, the differences between *nix files/file systems and lesser operating systems, and some HTML basics. Uh... more Perl knowledge is always a good thing too. :-) I'm not putting you down, we all have to start somewhere, and you *have* started. Keep plugging away at it, you'll get there. Here's a little framework that you may find useful in playing with CGI 'stuff'. use #!perl as the shebang for Apache on Windows (typically) #!/usr/bin/perl use warnings; use strict; # use CGI qw( :cgi ); # use Whatever::Module; our %V; # useful global # browser error dump routine (with Caller_error_path, EOF) # does NOT catch earlier errors (if any) above # also has a tendency to mess with $@ so using eval # to trap errors won't do what you think it should $SIG{'__DIE__'} = $SIG{'__WARN__'} = sub { my $error = shift; chomp $error; $error =~ s/[<&>]/"&#".ord($&).";"/ge; # entity escape; $error = &Caller_error_path( $error,1,0 ); &print_mime_type; print "$error\n"; exit 0; }; # test code goes here &print_mime_type; print "Success<br>\n"; # uncomment line below to test error trapping # print &unknown_subroutine; ############### ## utility subs # makes it easy to pass specific mime types, stops multiple # mime types from being printed due to programmer error # defaults to text/html sub print_mime_type { my $type = shift; $V{'MIME_DONE'} and return; $type ||= 'text/html'; print "Content-type: $type\n\n"; $V{'MIME_DONE'}++; } # constructs trace back to see where you failed and how you got there # I've had this around for years, no doubt could be cleaned up a bit sub Caller_error_path { my $error = shift; my $Shift = shift; my $Pop = shift; $error ||= ''; my $i = 0; my @call_list = (); while( my($p, $f, $l, $s, $h, $w ) = caller($i++) ){ my $string = ''; $f and $string .= "$f, "; $l and $string .= "Line: $l\n"; $s and $s !~ /main::__ANON__/ and $string .= "$s, "; push @call_list, $string; } $Shift and shift @call_list; $Pop and pop @call_list; @call_list = reverse @call_list; my $path = qq~ <form> <input type="button" Value="Back to Last Page" onclick="window.history.go(-1)"> </form> Trace: ~; $path .= join '', @call_list; return qq~ <pre>$path\n<span style="color: #FF0000;">$error</span></pre> ~; 1; # not required here, but IS for required library files If someone else sees a major problem in any of the above, you have my full attention. :-) hth, \s -- "There is no use in your walking five miles to fish when you can depend on being just as unsuccessful near home." M. Twain
From: Tad McClellan on 22 Apr 2010 20:50
John <John.Smith(a)invalid.com> wrote: > Is this a bug in Perl Asking that is a good way to get your future posts ignored, so you should resist the urge to ask it. -- Tad McClellan email: perl -le "print scalar reverse qq/moc.liamg\100cm.j.dat/" The above message is a Usenet post. I don't recall having given anyone permission to use it on a Web site. |