comment on

Hello All!

I've poked around a good bit, and futzed a lot with this, to no avail, so..... here's the question.

Looking at this node, i'm told that it's pretty easy to add a line to the beginning of a file:

   Here's another common problem which is trivially solved
   by Tie::File. How do I add a new record at the beginning
   of a file instead of at the end?

        unshift @lines, $new;   # Or add more than one record
[download]

Pretty much the same thing is said in the Tie::File pod

My problem is that my code (below the readmore) appears to:

Overwrite the first line of the target file, rather than insert a new first line.
Overwrite part of the next (second) line if the text being inserted is longer than the previous first line (the one being overwritten)

What do i want? I want to have the line in question inserted at the beginning of the file, as described in the quote/outtake above. It seems obvious that i'm doing something wrong, but i can't figure out what. I've pasted the offending sub below (yes, the script is running with -w), as well as some the STDERR output.

Thanks greatly for your attention!

####################
sub update_threads() {

my $parent = $_[0];
my $msg_id = $_[1];
#check if this is a top-level, and set $parent accordingly
if ($parent eq 'top') {
    $parent = $msg_id
}


my $main_threads_file = $htdocs . $path_info . "/threads.html";
my $archive_threads_file = $htdocs . $path_info . "/posts/" . $date . 
+"threads.html";
my $post_location = $path_info . "/posts/" . $date . "/" . $parent . "
+_" . $msg_id . ".html";
my $post_name = $parent . "_" . $msg_id;
my @threads;
my @archive;
my $link = "<li> <!-- mid=\"$post_name\" --> <a href=\"$post_location\
+">" . $params{"subject"} . "</a> by " . $params{"name"} . "  <font si
+ze=\"-1\">on " . $time . "</font>";

tie @threads, 'Tie::File', $main_threads_file or syslog('err', "update
+_threads couldn't open file: $main_threads_file");

if ($parent == $msg_id) {
    unshift @threads, $link;
}


untie @threads;

return;

} ## end sub update_threads()    
#***************************
[download]

the STDERR Below (can i nest readmore tags? hmmm) is the full output to the STDERR during one run... i know much of it is irrelevant, and i strongly suspect that the Tie::File errors are irrelevant too, but i'm not sure...

anyhow,

main::get_date() called too early to check prototype at
 /usr/local/apache/cgi-bin/bthreads-perl line 50.
main::read_config() called too early to check prototype at
 /usr/local/apache/cgi-bin/bthreads-perl line 53.
main::print_postform() called too early to check prototype
 at /usr/local/apache/cgi-bin/bthreads-perl line 63.
main::read_mcount() called too early to check prototype at
 /usr/local/apache/cgi-bin/bthreads-perl line 90.
main::get_date() called too early to check prototype at 
/usr/local/apache/cgi-bin/bthreads-perl line 92.
main::generate_post() called too early to check prototype at
 /usr/local/apache/cgi-bin/bthreads-perl line 95.
main::update_threads() called too early to check prototype
 at /usr/local/apache/cgi-bin/bthreads-perl line 98.
main::get_date() called too early to check prototype at
 /usr/local/apache/cgi-bin/bthreads-perl line 50.
main::read_config() called too early to check prototype at
 /usr/local/apache/cgi-bin/bthreads-perl line 53.
main::print_postform() called too early to check prototype
 at /usr/local/apache/cgi-bin/bthreads-perl line 63.
main::read_mcount() called too early to check prototype at
 /usr/local/apache/cgi-bin/bthreads-perl line 90.
main::get_date() called too early to check prototype at
 /usr/local/apache/cgi-bin/bthreads-perl line 92.
main::generate_post() called too early to check prototype at
 /usr/local/apache/cgi-bin/bthreads-perl line 95.
main::update_threads() called too early to check prototype
 at /usr/local/apache/cgi-bin/bthreads-perl line 98.
Use of uninitialized value in read at 
/usr/lib/perl5/5.6.1/Tie/File.pm line 699.
Use of uninitialized value in read at 
/usr/lib/perl5/5.6.1/Tie/File.pm line 699.
Use of uninitialized value in read at 
/usr/lib/perl5/5.6.1/Tie/File.pm line 699.
Use of uninitialized value in read at 
/usr/lib/perl5/5.6.1/Tie/File.pm line 699.
Use of uninitialized value in read at 
/usr/lib/perl5/5.6.1/Tie/File.pm line 699.
Use of uninitialized value in read at 
/usr/lib/perl5/5.6.1/Tie/File.pm line 699.
Use of uninitialized value in read at 
/usr/lib/perl5/5.6.1/Tie/File.pm line 699.
Use of uninitialized value in read at 
/usr/lib/perl5/5.6.1/Tie/File.pm line 699.
Use of uninitialized value in read at 
## and so on
[download]

update (broquaint): changed <pre> tags to <code> and dropped a chunk of repeated error messages

In reply to Tie::File strangeness with unshift by u914

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