#! /usr/bin/perl

if ( ($#ARGV < 0) || ($#ARGV > 1) ) {
    print "showplot: Wrong number of arguments.\n";
    print "\n";
    print "Usage: showdata input_filename [ 'plot_arguments' ]\n";
    print "\n";
    exit 1;
}

# Process the command line arguments.

$input_filename = $ARGV[0];

if ( $#ARGV == 0 ) {
	$plot_arguments = "\$f[0]";
} else {
	$plot_arguments = $ARGV[1];
}

# Open the input file.

open(INPUT, $input_filename) || die "Cannot open file '$input_filename'";

#### Look for file type identifier in the first line of the file. ####

$input_line = <INPUT>;

if ( ! defined( $input_line ) ) {
	print STDERR "No text in plot file.\n";
	exit 1;
}

@line1 = split(/ /, $input_line);

if ( $line1[0] eq "#" ) {
	if ( $line1[1] eq "SFF" ) {
		# Skip header of current SFF file.

		$num_header_lines = $line1[3];

		for ( $i = 0; $i < $num_header_lines; $i++ ) {
			$input_line = <INPUT>;

			if ( ! defined( $input_line ) ) {
			    print STDERR "SFF header terminated at line $i\n";
			}
		}
	}
}
if ( $line1[0] eq "SFF" ) {
	# Skip header of old SFF file.

	$num_header_lines = $line1[2];

	for ( $i = 0; $i < $num_header_lines; $i++ ) {
		$input_line = <INPUT>;

		if ( ! defined( $input_line ) ) {
			print STDERR "SFF header terminated at line $i\n";
		}
	}
}
if ( $line1[0] eq "MRCAT_XAFS" ) {
	# Skip header of MRCAT XAFS file.

	$num_header_lines = 17;

	for ( $i = 0; $i < $num_header_lines; $i++ ) {
		$input_line = <INPUT>;

		if ( ! defined( $input_line ) ) {
		    print STDERR "MRCAT_XAFS header terminated at line $i\n";
		}
	}
}

#### Process the data file. ####

@parameters = split( /;/, $plot_arguments );

while ($input_line = <INPUT>) {

	@f = split( " ", $input_line );

	print STDOUT $f[0] . " ";

	shift @f;

	for ( $i = 0; $i <= $#parameters; $i++ ) {

		$result = eval "$parameters[$i]";

		if ( ! defined($result) ) {
			print STDERR
"Error evaluating expression '$parameters[$i]'.  Result set to 0.\n";

			$result = 0;
		}
		print STDOUT $result . " ";
	}
	print STDOUT "\n";
}

close(INPUT);