# Script:  godir
# Written: 05-16-11 13:49:17 By: AWJurgensen
# Implements "go" utility. go to a directory maintained from an array
# go is a cd/pushd/popd replacement, that saves your paths for future go's
# environment variable GODIR contains all directory entries
# EDIT flds array definition below for your shell:  ksh or bash
# LOAD it up by sourcing into your shell:   . godir.sh

GOUSAGE='Example usage of the go command (a cd/pushd/popd/dirs alternative):
  go          list the GODIR directory array
  go 2        goto directory entry 2
  go -3       remove directory entry 3
  go -!       remove all directory entries
  go -?       show this usage help
  go newdir   cd to newdir, creating new entry
  go 9:newdir cd to newdir, creating/updating entry 9
  go w:/work  cd to work, creating/updating entry w'


# this is the array in var=val:var=val format
#GODIR=0=/full/path:1=/path
typeset GODIR
export GODIR

# Usage: Array {add|del|get|dump|exists|arrayadd} [pair]
# pair is in format: var=value
function GoArray {
  #set -x
  typeset cmd=${1} pair=${2}
  typeset -i add=0 delete=0 get=0 dump=0 debug=0
  case $cmd in
    add)        add=1 ;;
    del*)       delete=1 ;;
    get)        get=1 ;;
    dump)       dump=1 ;;
    exists)     if [ "$(echo "$GODIR" |grep ${pair}=)" != "" ] ; then
                  return 0
                else
                  return 1
                fi ;;
    arrayadd)   if [ "$GODIR" != "" ] ; then
                  GODIR="$GODIR:$pair"
                else
                  GODIR="$pair"
                fi
                return ;;
    *)          echo "Array: Unsupported action $cmd"
                return ;;
  esac
  typeset OIFS IFS field var value flds
  typeset -i err=0 i=0 numflds=0

  ((debug)) && print -u2 "pair: $pair"
  OIFS=$IFS
  IFS=:
  set -A flds -- ${GODIR}       # ksh only;  load array flds
  # flds=(${GODIR})             # bash only; load array flds
  IFS=$OIFS
  numflds=${#flds[*]}
  if [[ add -gt 0 ]] ; then
    add=numflds
    GoArray arrayadd "$add=$pair"
    return
  fi
  GODIR=""
  # loop thru all N=/path entries:
  while [[ i -lt numflds ]]; do
    field=${flds[i]}
    IFS==
    set -- $field
    IFS=$OIFS
    var=${1}
    value=${2}
    if [[ delete -gt 0 && $var = "$pair" ]] ; then
      ((debug)) && print -u2 "deleting: $pair"
    elif [[ get -gt 0 && $var = "$pair" ]] ; then
      echo "$value"
      GoArray arrayadd "$field"
    elif [[ dump -gt 0 ]] ; then
      printf "%-2.2s %s\n" $var "$value"
      GoArray arrayadd "$field"
    # Add is handled before the loop
    #elif [[ add -gt 0 -a add -eq i ] ; then
    #  GoArray arrayadd "$add=$pair"
    else
      GoArray arrayadd "$field"
    fi
    ((i+=1))
  done
}

# go is a cd replacement, that stores your directories for future go's
function go
{
  NUL=/dev/null
  #set -x
  case "$1" in
    -!)  GODIR="" ;;
    -\?) echo "$GOUSAGE" ;;
    -*)  GoArray del ${1#-}
         GoArray dump | sort ;;
    *:*)  lbl=${1%:*} # remove pattern on right
          dir=${1#*:} # remove pattern on left
          if [ -d "$dir" ] ; then
           cd "$dir" >$NUL ; echo go: $(/bin/pwd)
           # Check if were replacing an entry. then do delete, add:
           GoArray exists ${lbl} && GoArray del ${lbl}
           GoArray arrayadd "${lbl}=$(/bin/pwd)"
         else
           GoArray dump | sort
         fi ;;
    *)   if [ -d "$1" ] ; then
           cd "$1" >$NUL ; echo go: $(/bin/pwd)
           GoArray add "$(/bin/pwd)"
         else
           GO=$(GoArray get "$1")
           if [ -d "$GO" ] ; then
             cd "$GO" >$NUL ; echo go: $(/bin/pwd)
           else
             GoArray dump | sort
           fi
         fi ;;
  esac
}

# load go function (a cd alternative)
. $HOME/bin/godir.sh
# load up our favorite directories for use by: go
GODIR='0=/home/alan:b=/home/alan/bin:d=/home/alan/doc:s=/home/alan/shells:p=/home/alan/perl:w=/work:m=/data/media/mp3:l=/var/log:t=/tmp'
alias g='cd' # go home
alias b='cd -' # go back to previous dir

    exists)     if [ "$(echo "$GODIR" |grep ${pair}=)" != "" ] ; then

    exists)     if [[ :"$GODIR": == *:${pair}=* ]] ; then