#!/usr/bin/perl

# Routine to sort the LSPN calib/ directory  be referencing the DATE-OBS
# in the FITS headers.
#============================================================================
# Loop through the header files in the current directory:

opendir(CAL,".") || die "Could not open directory for reading ($!)";

foreach $file (sort readdir(CAL))
  { next if ($file !~ /hdr$/);    # Only interested in FITS headers

    # Now we'll open the header by piping it through 'brkstrm',
    # looking for the 'DATE-OBS' line:

    open(HDR,"brkstrm < $file |") ||
      die "Could not open brkstrm pipe for $file ($!)\n";

    $line = <HDR>;    # First line is not the one we're looking for.
    $line = <HDR> while ($line !~ /^DATE-OBS/);
    $line =~ /^DATE-OBS=\s*'(.*)\/(.*)\/(.*)\s*'/;
    $day   = $1;
    $month = $2;
    $year  = 1900 + $3;

    close(HDR);   # Done with this now.

    $datadir = "$year/$month/$day";

    # We do need to create these directories if they don't already
    # exists, so we better check before copying:

    mkdir "$year" if (! -d "$year");
    mkdir "$year/$month" if (! -d "$year/$month");
    mkdir "$year/$month/$day" if (! -d "$year/$month/$day");

    # We'll need to replace the file extension with ".*":

    $file =~ s/\.hdr/.*/;

    # And now we're ready to move: 

    system "mv $file $datadir";
        
    # On to the next file....

  }

closedir(CAL);