#! usr/bin/perl

opendir(FILES,".")||die "Cannot open files in the directory\n";
@files=();
for(readdir(FILES)){
    if($_=~/\.txt/){
        push(@files, $_);
    }
}
print "@files\n";
for $i(0..$#files){
print "working on $files[$i]\n";
open (FH, "+<$files[$i]") or die "can't update $file: $!";
my $linevalue;
while ( $linevalue = <FH> ) {
    $addr = tell(FH) unless eof(FH);
    last if (eof(FH));
}

if($linevalue eq "\n")
{
  truncate(FH, $addr) or die "can't truncate $file: $!";
}
exit;
[download]

Thank you so much for your reply.
I really don't know how to thank you enough!
This script did exactly what I needed to do.
I modified it a little bit at the end.
Thank you again!

#! usr/bin/perl

opendir(FILES,".")||die "Cannot open files in the directory\n";
@files=();
for(readdir(FILES)){
    if($_=~/\.txt/){
        push(@files, $_);
    }
}
print "@files\n";
for $i(0..$#files){
print "working on $files[$i]\n";
open (FH, "+<$files[$i]") or die "can't update $file: $!";
my $linevalue;
while ( $linevalue = <FH> ) {
    $addr = tell(FH) unless eof(FH);
    last if (eof(FH));
}

if($linevalue =~ /^\s*$/)
{
  truncate(FH, $addr) or die "can't truncate $file: $!";
  print "truncated the last blank line in $files[$i]\n";
}else{
    print "$files[$i] does not end with blank line\n";
}
}
exit;
[download]

It's fast, but doesn't do what you want..

This may be a silly question, but what about using the File::ReadBackwards module? It has a 'tell' function, which should give you the value for the file pointer at the beginning of the last line which has been read. With this information, use truncate to trim off the unwanted line. (When I get a test case, I'll post my (probably hideously ugly) sample code)

Alternatively, you could do this (which qualifies as ugly)

open(FILE, $file) or die "$file could not be opened because $!\n";
@slurp = <FILE>;
close(FILE);
pop(@slurp) if $slurp[-1] =~ /^\s*$/;
open(FILE, "> $file") or die "$file could not be opened because $!\n";
print FILE @slurp;
close(FILE);
[download]

I did say it was ugly...

#!/usr/bin/perl

while(<./*.txt>){
print "working on $_\n";
open (FH, "+<$_") or die "can't update $file: $!";
$l=$_ while <FH>;
truncate FH, tell(FH) - 1 if $l =~ /^$/;
}
[download]

No need to seek through the file. You already know that what you want to get rid of, if it’s there at all, is at the very end.

#! usr/bin/perl
use strict;
use warnings;

# length of end-of-line marker
my $eol_len = length $/;

opendir my $dh, "." or die "Can't open current directory: $!\n";

while( my ( $file ) = readdir $dh ) {
    next if $file !~ /\.txt/;

    open my $fh, '+<', $file
        or warn( "Can't open $file for read/write: $!\n" ), next;

    # read data from last possible location of end-of-line
    seek $fh, -$eol_len, 2;
    my $tail = <$fh>;

    # if chomp finds an EOL, rewind and truncate
    if( chomp $tail ) {
        seek $fh, -$eol_len, 2;
        truncate $fh, tell $fh;
    }
}
[download]

Makeshifts last the longest.

Neat.

And you can shorten that some:

perl -pi.bak -0777e's{ ^ \n \z }{}xms' *.txt
[download]

Makeshifts last the longest.

#!/usr/bin/perl -w

use strict;

my ($myfile, @LINES);
open $myfile, "file" or
    die "Unable to open file: $!\n";
push @LINES, $_ for (<$myfile>);
#print "$_" for @LINES;
chomp ($LINES[$#LINES-1]) if ( $LINES[$#LINES] =~ m/\s+/ );
#print "$_" for @LINES;
[download]

#!/usr/bin/perl

my @file = qx/cat file/;
chomp ($file[$#file]) if $file[$#file] =~ m/\s+/;
[download]

OT: I once had need to remove the first line from a file and did it with this shell script...

# this once had a purpose... 
LINES=$(wc -l $1 | awk '{print $1}')
tail -$(echo $LINES - 1 | bc -l) $1
[download]

Ted
--
"That which we persist in doing becomes easier, not that the task itself has become easier, but that our ability to perform it has improved."
  --Ralph Waldo Emerson