#!/usr/bin/perl

# Hey! - A better write, and a quick mailer..
# Oct 1996 Murf.

# This version (C) March 2004
# Ver : 4.0

# hey, 1996-2000,2003,2004 Damian Murphy

# The Perl Version of the csh version of the Perl version! ;)
# Lots of this code was written by Anon @maths.tcd.ie
# I'm in the process of hacking it together with my own csh-hey
# Feel free to play around with it.

#Declare some sub-functions

#Check if a username exists on the system
sub exists {
	local (@r) = getpwnam ($_[0]);
	$#r != -1;
}

#Check if a user 'owns' a tty
sub owns {
	local ($who, $which) = ($_[0], $_[1]);
	local ($uid, $_);
	$uid = ((getpwnam ($who))[2]);
	$uid == (stat ("/dev/$which"))[4];
}


#Startup...
print STDERR "This is Hey, v4.0\n";

#Check our command-line
if ( $#ARGV == -1 ) {
	print STDERR "Usage: hey (user) [ (user2) (user3) ... ]\n";
	exit 1;
}


#Check if the hey files are there...


#test for valid user...
#Stops the program unless we get at least one valid target

@users = ();
@ttys = ();
arg: while ( $_ = shift ) {
	if ( /^(.*)\.(.*)$/ ) {
		$_ = $1;
		$histty = $2;
		if ( -c $histty ) {
			s:^/dev/::;
		} elsif ( -c "/dev/tty$histty" ) {
			$histty = "tty$histty";
		} elsif ( ! -c "/dev/$histty" ) {
			print STDERR "no such terminal: $histty\n";
			next arg;
		}
		if ( &exists ($_) ) {
			if ( &owns ($_, $histty) ) {
				push (@users, $_);
				push (@ttys, $histty);
			} else {
				print STDERR "$_ does not own $histty\n";
			}
		} else {
			print STDERR "user $_ does not exist\n";
		}
	} else {
		if ( &exists ($_) ) {
			push (@users, $_);
			push (@ttys, '');
		} else {
			print STDERR "user $_ does not exist\n";
		}
	}
}
exit 1 unless @users;


if ( $#users == 0 ) {
	print STDERR "Recipient : ";
	print STDERR "@users\n";
}
else{
	print STDERR "Recipients : ";
	print STDERR "@users\n";
}


# Read in message
undef $/;
$* = 1;
@message = split ("\n", <STDIN>);
# Do something with tabs
foreach (@message) {
	next unless /\t/;
	local (@b) = split ('\t', $_);
	$_ = shift @b;
	foreach $x (@b) {
		$_ .= ' ' x (8 - (length ($_) % 8));
	}
}

# Format message - put box around it and add signature
$maxlength = 0;
foreach (@message) {
	$maxlength = length ($_) unless length ($_) < $maxlength;
}
grep (($_ = '| ' . $_ . (' ' x ($maxlength - length)) . ' |'), @message);
unshift (@message, '-' x ($maxlength + 4));
push (@message, '-' x ($maxlength + 4));

# Centre on 80 columns
if ( $maxlength < 76 ) {
	$pad = ' ' x ((76 - $maxlength) / 2);
	foreach (@message) {
		$_ = $pad . $_ . $pad;
	}
}

#Now, send it!
foreach (@users) {
	print STDERR "$_: ";
	$histty = shift @ttys;
	unless (open (WRITE, "|/usr/bin/write $_ $histty") ) {
		print STDERR "Can't run write: $!\n";
		next;
	}
	print WRITE "\nHey there, $_ ...\n";
	foreach $line (@message) {
		print WRITE $line, "\n";
	}
	close WRITE;
	print STDERR "Hey...\n" unless $?;
}


#Bye!