#!/usr/athena/bin/perl

# process-comments.pl 
# Aneel Nazareth (achmed@mit.edu)
# for usage type process-comments.pl -h
# for documentation see http://web.mit.edu/cwis/faq/process-comments.html
# comments to cwis-help@mit.edu
# last updated 01/08/2001
# by Matthew Seegmiller (xaco@mit.edu)

$begin_record = '{begin-record}';
$field_separator = '{field-separator}';
$end_record = '{end-record}';

$separator = "\t";
$return_conversion = ' ';
$return_cvt = 1;
$separator_conversion = ' ';
$separator_cvt = 1;
$append = 1;
$verbose = 1;
$lineno = 1;
$linenos = 0;
$outfile = 'process.out';

$switches='';
while (@ARGV) {
    $cmdlinearg = shift @ARGV;
    
    if ($cmdlinearg =~ /^([-+])([^ ]*)/) {
	if (($2 eq 'h') || ($2 eq 'help')) {
	    die "For documentation see http://web.mit.edu/cwis/faq/process-comments.html\n";
	} 
	
	# -o controls outfile
	$outfile = shift @ARGV if ($2 eq 'o');
	# print "outfile: $outfile\n";
	
	# +/-a controls appending
	$append = ($1 eq '+') if ($2 eq 'a'); 
	
	# +/-v controls verbosity
	$verbose = ($1 eq '+') if ($2 eq 'v'); 
	
	# +/-r controls return conversion
	$return_conversion = shift @ARGV if ($2 eq 'r') && ($1 eq '+');
	$return_cvt = 0 if ($2 eq 'r') && ($1 eq '-');
	
	# +/-t controls separator conversion
	$separator_conversion = shift @ARGV if ($2 eq 't') && ($1 eq '+');
	$separator_cvt = 0 if ($2 eq 't') && ($1 eq '-');
	
	# -s controls separator
	$separator = shift @ARGV if ($2 eq 's');
	
	# +/-n controls line-numbering
	$linenos = ($1 eq '+') if ($2 eq 'n');

	# -br -fs -er control separators
	$begin_record = shift @ARGV if ($2 eq 'br');
	$field_separator = shift @ARGV if ($2 eq 'fs');
	$end_record = shift @ARGV if ($2 eq 'er');

  } else {
    push(@infiles,$cmdlinearg);
  }
}

if ($append) {
  open(OUTFILE,">>$outfile") || die "Can't open target file $outfile: $!, stopped at";
  warn "Appending to file '$outfile'\n";
  if ($linenos) {
      open(LINENO,"wc -l $outfile |");
      $_=<LINENO>;
      $lineno=1+$& if m/\d+/;
      close(LINENO);
      warn "Starting with record number $lineno\n";
  }
} else {
  if (-e $outfile) {
    print STDOUT "File $outfile exists. Replace? ";
    $_=<STDIN>;
    exit if /n/;
  }
  open(OUTFILE,">$outfile") || die "Can't open target file $outfile: $!, stopped at";
}

select OUTFILE;

foreach $infile (@infiles) {
  open(INFILE,"<$infile") || die "Could not open $infile: $!, stopped at";
   
  print STDOUT "  Processing $infile...\n" if $verbose;

  while(<INFILE>) {
 
      if (s/^$begin_record(\n)?//) {

      print STDOUT "    record " if $verbose;
      print $lineno++,"\t" if $linenos;
      while(defined $_) {
	
        if (s/$end_record(\n)?//) { 
	    print "\n"; 
	    print STDOUT "\n" if $verbose; 
	    last; 
	}
        
	s/$separator/$separator_conversion/gi if $separator_cvt;
        print STDOUT "field " if
	  (s/$field_separator(\n)?/$separator/gi) && $verbose;
        s/\n/$return_conversion/ if $return_cvt;

	print;
	$_ = <INFILE>;
      }
    }
  }
  close(INFILE);

  print STDOUT "  done.\n" if $verbose;
}
close(OUTFILE);

print STDOUT "Finished.\n" if $verbose;