That would be the Formosan Hundred-pace (or conehead) snake, whose bite causes skin and muscles to darken and deteriorate, accompanied by blistering and blood-tinted discharge and a slight burning sensation.

Assuming you've opened the file using the filehandle FILE, the following should work:

while ( <FILE> ) {
    last if /^TITLE (.*)$/;
}

$title = $1;

while ( <FILE> ) {
    last if not /^TITLE (\d*) (.*)/;
    $title .= ' ' . $2;
}
[download]

It's not clear if the only thing you want is the first occurence of TITLE, but assuming it is, the simplest thing to do is to just stop processing your input stream once you are done with first set of title lines. And if you want to avoid "flag" vaiables, you can allways use a nested loop over the input handle.

something like this (psuedo-perl) perhaps...

while (<STDIN>) {
    next unless /^TITLE\s+(.*)$/;
    my $title = $1;
    while (<STDIN>) {
        last unless /^TITLE\s+\d+\s+(.*)$/;
        $title .= $1
    }
    print "Here is the title you wanted: $title";
    last;
}
[download]

If your files contain multiple headers just flag it and get on with it.... If not just exit after the initial run of TITLE tokens runs out

my $header = 0;
my $title  = 0;
my $string = '';

while (<DATA>) {
    $header = 1 if /^HEADER/;
    $title  = 1 if /^TITLE/ and $header;
    if ( $header and $title ) {
        if ( /^TITLE\s+(.*)/ ) {
          $string .= $1;
        } else {
            $header = $title = 0;
            $string =~ s/\s+/ /g;
            print "$string\n";
            $string = '';
        }
    }
}    


__DATA__
HEADER    METAL BINDING PROTEIN                   31-AUG-98   1BSW    
+          
TITLE     ACUTOLYSIN A FROM SNAKE VENOM OF AGKISTRODON ACUTUS AT PH   
+          
TITLE    2 7.5                                                        
+          
COMPND    MOL_ID: 1;                                                  
+          
COMPND   2 MOLECULE: ACUTOLYSIN A; 
TITLE    NO 2 7.5  
TITLE    NO 2 7.5  

HEADER    METAL BINDING PROTEIN                   31-AUG-98   1BSW    
+          
TITLE     ACUTOLYSIN A FROM SNAKE VENOM OF AGKISTRODON ACUTUS AT PH   
+          
TITLE    1 2 3 4 5                                                    
+              
COMPND    MOL_ID: 1;                                                  
+          
COMPND   2 MOLECULE: ACUTOLYSIN A; 
TITLE    NO 2 7.5  
TITLE    NO 2 7.5
[download]

cheers

tachyon

s&&rsenoyhcatreve&&&s&n.+t&"$'$`$\"$\&"&ee&&y&srve&&d&&print

To propose a really fitting solution, we need to see some code.

How do you extract the title? Do you read it in a separate run through the file? Do you have a loop that does one of several things depending on what the current line starts with? What else is your code doing? The solution will differ depending on your existing implementation.

I am guessing that: the information is all located in a single file, you're only doing one iteration over it, and all pieces of information follow the format you already showed (ie if broken across multiple lines, the following lines start with the same tag followed by a line number).

In that case, the way I'd handle this is to read the lines batchwise, reconstruct them into a single line, then hand it off to the appropriate handler.

my %handler = (
    HEADER => sub { ... },
    TITLE  => sub { ... },
    COMPND => sub { ... },
);

my ($tag, $text) = ("")x2;
while(<>) {
    chomp;
    my ($curr_tag, $curr_text) = split /\s+/, $_, 2;
    if($curr_tag ne $prev_tag) {
        $handler{$tag}->($tag, $text) if exists $handler{$tag};
        # complain_about_unknown() if not exists $handler{$tag}; ?
        ($tag, $text) = ($curr_tag, "");
    }
    else {
        my $curr_linenr;
        ($curr_linenr, $curr_text) = split /\s+/, $curr_text, 2;
        # perform validation on line nr here?
    }
    $text .= " " . $curr_text;
}
[download]

my %record;

my %handler = (
    # ...
    TITLE => sub { $record{TITLE} = $_[1] unless exists $record{TITLE}
+ },
    # ...
);
[download]

my $curr_rec = 0;
my @record;

my %handler = (
    # ...
    HEADER => sub { ++$curr_rec },
    TITLE  => sub {
        $record[$curr_rec]->{TITLE} = $_[1]
            unless exists $record[$curr_rec]->{TITLE}
    },
    # ...
);
[download]

Makeshifts last the longest.

Can anyone think of an elegant way to grab the first block of 1+ contiguous TITLE lines, and stop?

my $title;
for (@data) {
    if (/^TITLE\s+\d*(.*)/) {
        $title .= $1;
    } else {
        last if defined $title;
    }
}
[download]

The elegance would be in not adding a flag but rather reusing $title for that purpose (since it already contains the state the flag would save).

— Arien

'cept that that will bottle out too early unless the first line is a title line (which it isn't)?

Update: Talking That which begins with B and ends in ollocks again. Arien++

---

Examine what is said, not who speaks.