Your file "open mode" is wrong, use '<' for read-only. 
#!/usr/bin/perl -w 
use strict; 

my @words; 
open FILE, "<", "input.txt" or die "unable to open input.txt $!"; 
print "file loaded \n";

while (<FILE>) 
{ 
   @words = split(' ', $_); 
   push @all_words, @words;
} 

foreach $word (@words) 
{ 
   print "$word\n";
}


__END__

# if you want to count the words
# then that is different - use a hash
# table of "word => count"

#the default split (/\s+/,$_)
#differs only between this special case split(' ',$_)
#in how it handles a "null" field at the beginning of the line

my %words;
while (<FILE>) 
{ 
   my @words = split; 
   foreach my $word (@words)
   {
      $words{$word}++;
   }
} 

=== or ===

my %words;
while (<FILE>) 
{ 
   foreach my $word (split)
   {
      $words{$word}++;
   }
} 

==== or ===
my %words;

while (<FILE>) 
{ 
   $words{$_}++ foreach (split);
}

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In reply to Re^3: putting text into array word by word by Marshall
in thread putting text into array word by word by jms53

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