#!/local/bin/perl

# Routine to add numbers to the beginning of each line in a (presumably)
# text file.
#
#  Format:  % linnum [-w digits] [ input_file [ output_file ] ]
#
#  where  -w digits    indicates the width of the output line number field.
#                      default is 5 digits.  An additional space will also 
#                      be inserted between the number and the first byte
#                      of the line.
#
# 24 Aug 1999, acr.
#
#==========================================================================

# First, see if we have to open a file or if we've gotten a pipe:

if (@ARGV > 4) 
  { die "Usage: linnum [-w digits ] [ input_file [ output_file ] ]\n"; }

$w       = 5;
$infile  = "-";
$outfile = "-";

while (@ARGV > 0)
  { $a = shift(@ARGV);
    if ($a eq "-w")
      { $w = shift(@ARGV); }
    elsif ($infile eq "-")
      { $infile = $a; }
    elsif ($outfile eq "-")
      { $outfile = $a; }
    else
      { die "Usage: linnum [-w digits ] [ input_file [ output_file ] ]\n"; }
  }

if ($w < 1)
  { die "Invalid integer width ($w).\n"; }

# Open the I/O streams:

open (IN,"$infile") || die "Could not open \"$infile\" for reading. ";
open (OUT,">$outfile") || die "Could not open \"$outfile\" for writing. ";

$count = 0;
while ($line=<IN>)
  { $count++;
    printf OUT "%${w}.${w}d %s",$count, $line;
  }

# Close the streams and we're done:

close(IN);
close(OUT);