Newbie
Basic XML parser. I noted an "EMPTY???" comment beside the area which doesn't print anything. It's strange because the variables do get filled properly...anyone have any ideas?
Code:#!/usr/bin/perl -w my $title = ""; #title my $link = ""; #link my $description = ""; #description my $item_found = 0; # <item> element within the xml file print "<html>\n"; print "\n\t<body>\n"; #read xml file from standard input while( $line = <stdin> ) { #remove white space chomp( $line ); if( $item_found == 0 ) { $start = index( $line, "item" ); #find an item tag if( $start != -1 ) { $item_found = 1; #beginning of item } } if( $item_found == 1 ) { #parse data that we want $title = &process_element( $line, "title" ); $link = &process_element( $line, "link" ); $description = &process_element( $line, "description" ); #look for the end of item tag $end = index( $line, "/item" ); if( end != -1 ) { #print the gathered information to the html file if( length( $title ) != 0 || length( $link ) != 0 || length( $description ) != 0 ) { print "\n\t\t<p> \n\t \t\t<a href= \"$link\"> $title </a> \n\t\t\t $description \n\t\t</p>\n\n" ; #EMPTY???? } #clear stored information $title = ""; $link = ""; $description = ""; $chann_found = 0; #end of channel $item_found = 0; #end of item } } } #$_[0] = line, $_[1] = tag sub process_element { #my ( $start, $end, $length ); #private local variables #my $information = ""; #Grab the string between these tags $start = index( $_[0], "$_[1]" ); #assume this is how a beginning tag will always look $end = rindex( $_[0], "</" ); #this is how an ending tag will always look if( $start != -1 ) { $start = index( $_[0], ">" ) + 1; #advance start to the end of the tag $end = rindex( $_[0], "<" ); #advance start to the beginning of the closing tag $length = length( $_[0] ); #end tag wasn't on the same line if( $end == -1 ) { $end = $length; } $length = $end - $start; #the length of the substring $information = substr( $_[0], $start, $length ); #replace encoded characters if any exist $information =~ s/</</; $information =~ s/>/>/; $information =~ s/&/&/; return $information } } print "\n\t</body>\n"; print "\n</html>\n\n";
Newbie
never mind...i know what was wrong.
Can you explain what was wrong? Other users might have the same problem as you had.
Newbie
no problem. In subroutines a return value is not necessary, but you can include one. It doesn't follow the same structure as high level language though, notice how mine is inside an if statement, so it could in fact never execute, leaving my subroutine without a return value (not allowed in many languages). That was the issue, on certain cases the variables assigned to the subroutine value returned ended up either equaling nothing or whatever may be equivalent to void. So my variables would equal the correct value, but following another execution of the subroutine given a case where the return statement wasn't executed, they were overridden. I hope that makes sense....and is understandable. I just threw in a "error check" if statement to correct the problem.
Newbie
Thank you for sharing the issue with us this actually helped me with a build perl script that i have been having problems with.
Newbie
That was the issue, on certain cases the variables assigned to the subroutine value returned ended up either equaling nothing or whatever may be equivalent to void. So my variables would equal the correct value,
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