Fixing an error from using Loop to read a file

[Donnie Seibel]

I wrote a script to list all lines in a file with Perl. I am having trouble with the looping part of it. My script is supposed to look at the file and as long as the file is larger than the current line it prints a new line.

I am getting an error that won't stop on the while line of my code I believe.
Here is the code:

#!/usr/bin/perl -w
unless(scalar(@ARGV)==1){
   print "error: incorrect number of arguments",
   "\n",
   "usage: linenum.pl [filename]",
   "\n";
      exit 1;
}
 
# Open function used with  filehandle and input file.
open(MY_FILE, "$ARGV[0]") or die
   "error: argument must be a file\n",
   "usage: linenum.pl [filename]\n$!\n";
 
# Check if file is a directory
if (!-f "$ARGV[0]"){
   print "error: argument must be a file",
   "\n",
   "usage: linenum.pl [filename]\n";
   exit 1;
}
 
$COUNTER=1;  # Used for printing line numbers
 
# Loop and write lines from
while($LINE <= <MY_FILE>){
   # Adds leading zeros for numbers 1 digit long
   if ($COUNTER<10){
      print "000";
   }
   # Adds leading zeros for numbers 2 digits long
   if (($COUNTER>9) && ($COUNTER<100)){
      print "00";
   }
   # Adds leading zeros for numbers 3 digits long
   if (($COUNTER>99) && ($COUNTER<1000)){
   print "0";
   }
   # Prints line number and line
   print "$COUNTER: $LINE";
   $COUNTER+=1;
}
 
exit 0;
 
 

This is the error and I can't figure out what it means.

"Use of uninitialized value in numeric le (<=) at ./linenum.pl line 26, <MY_FILE> line 29

Use of uninitialized value in concatatenation (.) or string at ./linenum.pl line 40, <MY_FILE> line 29."

This error doesn't stop either I have to close my program to end it.

[RonB]

Your script has a number of problems, but lets start with this:

change line 26 ti this:

while( my $LINE = <MY_FILE> ){