#!/bin/bash

#+
# NAME:
#	goto
# PURPOSE:
#	Mounting/unmounting of removable disks (floppy,cdrom,zip)
# CALLING SEQUENCE
#	goto 'drive'
# RESTRICTIONS:
#	'drive' must be listed in /etc/fstab
# PROCEDURE:
# >	After checking /etc/fstab, the mount command is piped
#	through grep searching for 'drive'. If present the
#	drive is mounted.
# >	When bash is the default shell aliases can be defined as:
#		alias floppy=". goto floppy"
#		alias cdrom=". goto cdrom"
#		alias zip=". goto zip"
#	(i.e. the script is sourced)
#	In other shells (e.g. csh) the aliases need to be defined as
#		alias floppy "$COM/goto floppy"
# >	If 'drive' is not mounted yet then it is mounted, and
#	a 'cd' is made to the root directory 'drive'
# >	If 'drive' is mounted, then it is umounted. If the
#	current directory is on 'drive' then a 'cd' is made
#	to the previous working directory $OLDPWD. If this fails
#	then a 'cd' to the user home directory follows.
# MODIFICATION HISTORY:
#	FEB-2001, Paul Hick (UCSD/CASS)
#	FEB-2003, Paul Hick (UCSD/CASS)
#		Fixed problem detecting non-existing mount points
#	FEB-2003, Paul Hick (UCSD/CASS; pphick@ucsd.edu)
#		Instead of testing for "drive" test for "drive ".
#		The added space should avoid problems when e.g.
#		cdrom and cdrom1 exist.
#-

thing=$1

if [ "$thing" != "" ]; then

	# Check the mount points for entry containing $thing

	dir_thing=$(gawk /"$thing "/'{print $2}' /etc/fstab)
	dir_thing=$(echo $dir_thing | gawk '{print $1}')

	if [ -z "$dir_thing" ]; then
		echo "No mount point found for "$thing" in /etc/fstab"

	else

		dev_thing=$(gawk /$thing/'{print $1}' /etc/fstab)
		dev_thing=$(echo $dev_thing | gawk '{print $1}')

		mount | grep $dir_thing > /dev/null
		if [ $? = 0 ]; then
			echo $PWD | grep $dir_thing > /dev/null
			if [ $? = 0 ]; then
				cd $OLDPWD
				echo $PWD | grep $dir_thing > /dev/null
				if [ $? = 0 ]; then
					cd
				fi
			fi
			echo ....... unmounting $dev_thing from $dir_thing
			umount $dir_thing
		else
			echo ....... mounting $dev_thing at $dir_thing
			mount $dir_thing
			if [ $? = 0 ]; then
				cd $dir_thing
			fi
		fi
	fi
fi

# Probably redundant.

echo $0 | grep "/goto" > /dev/null
if [ $? = 0 ]; then
	exit 0
fi