#! /usr/local/bin/perl

#  datepage.pl - by David Efflandt <efflandt@xnet.com> - 9/24/95 [9/30/95]
#
#  Run this script in UNIX after updating any html files.
#  Any line beginning with $tag will be replaced with $update unless equal.
#  Nothing will change if the $tag line matches the current file date.
#
#  NOTE: Move any html tags to a separate line including <P> or <BR>.
#
#  Example:
#
#  <!--last update-->This line will be replace with current update
###

###  Change this to the string you want ending the line with a space.
###  Tag prefix and date suffix will be added.
$update_string = "This page was last updated ";

###  Change this to your list of Web pages to update
###  Use relative path from script or full path.
###  Surround each file with single quotes and follow with comma.
@list = (
'index.html',
'pub/index.html',
);

###  You should not have to change anything below this line  ###

#  The line in each file that begins with the tag in quotes will be replaced 
$tag = '<!--last update-->';

#  Get number of lines in file and old date line
print "\n";
print "Checking update string in Web pages\n\n";
foreach $file (@list) {
  open (PAGE,"<$file") || warn "Can't open $file: $!\n";
  @lines = <PAGE>;
  close(PAGE);
  $lines = @lines;
  next unless ($olddate = (grep (/$tag/, @lines))[0]);

# Get current file date and update line
  ($sec,$min,$hour,$mday,$mon,$year,$wday,$yday,$isdst
  ) = localtime(time - int((-M $file) * 86400));
  ++$mon;  #  increment because January is zero
  $date = "$mon/$mday/$year";
  $update = $tag . $update_string . $date . "\n";

#  Do nothing if olddate and update are the same
  if ($olddate eq $update) {
    print "$file remains at $date\n";
    next;
  }

# Open file to output
  open (PAGE,">$file");
  for ($i=0;$i<=$lines;$i++) {
     $_=$lines[$i];
    if (/$tag/) { 
      print PAGE $update;
      print "$file has been updated to $date\n";
    }
    else { print PAGE $_; }
  }
  close (PAGE);
}