#!/bin/sh

# dm 0.9 - Directory Manager
#  (Instructions below the license)
# LICENSE
# Copyright (C) 2007 Lluís Batlle i Rossell
# 
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.
# 
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
# 
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
#
# Instructions:
# 'dm' will manage a list of id-directory. 'dmcd' will allow the current shell
# to change to the directory given by 'id'.
#
# Examples:
#  $ dm 1 /tmp   # Adds the id '1' for /tmp
#  $ dm 2 .      # Adds the id '2' for the current dir
#  $ dmcd 1      # Goes to /tmp
#  $ dmcd 2      # Goes to what was your current dir
#  $ dm -d 2     # Deletes the entry for '2'.
#  $ dm          # Shows your 'database'
#  1     /tmp
#  $ dm -h       # Shows help, and defines 'dmcd' for sh.
#
# In order to use 'dmcd', you should define the function
# given by "dm -h" in your shell. Put it in your bashrc or
# a file like that.
#
# Your directory database is stored in ~/.dm .

function showdirs
{
    if [ -f ~/.dm ] ; then
        cat ~/.dm | sort
    fi
}

function testdir
{
    if [ "$1x" == "x" ]; then
        echo "Error: You should specify an alias for a directory." 1>&2
        return 1
    fi
    if [ -f ~/.dm ] ; then
        grep "^$1	" ~/.dm > /dev/null 2> /dev/null
        if [ $? -ne 0 ]; then
            echo "Error: There is no directory for '$1'" 1>&2
            return 1
        fi
    else
        echo "Error: There is no directory for '$1'" 1>&2
        return 1
    fi
}

function deldir
{
    # Remove the old def
    if [ -f ~/.dm ] ; then
        sed -i "/^$1\t/d" ~/.dm
    fi
}

function setdir
{
    # Remove the old def
    deldir $1
    NEWDIR=`getpath "$2"`
    # Add new
    echo "$1	$NEWDIR" >> ~/.dm
}

function getdir
{
    if [ -f ~/.dm ] ; then
        grep "^$1	" ~/.dm | sed 's/^[^\t]*\t//'
    else
        return 1
    fi
}

function showhelp
{
    echo "usage: $0 [ -l | -d id | -t id | id | id newdir ]"
    echo 'For sh: function dmcd { dm -t $1 && cd `dm $1`; }'
}

function getpath
{
    OLD=`pwd`
    cd "$1"
    pwd
    cd "$OLD"
}

# dm -t $1 && cd `dm $1`

if [ $# -lt 1 ]; then
    showdirs
elif [ $1 == "-l" ]; then
    showdirs
elif [ $1 == "-h" ]; then
    showhelp
elif [ $1 == "-d" ]; then
    deldir $2
elif [ $1 == "-t" ]; then
    testdir $2
elif [ $# -eq 2  ]; then
    setdir $1 $2
elif [ $# -eq 1  ]; then
    getdir $1
fi