# Directory Bookmarks for BASH (c) 2009-2010 Ira Chayut, Version 101216
#
# To use, save this file as ~/.bashDirB and add the following line to ~/.bashrc:
#
#        source ~/.bashDirB
#
# DirB and its implementation in this file are the product of and
# copyrighted by Ira Chayut.  You are granted a non-exclusive, royalty-free
# license to use, reporduce, modify and create derivative works from DirB;
# providing that credit is given to DirB as a source material.
#
# The lastest version is available from: http://www.dirb.info/.  Ira can
# be reached at ira@dirb.info.
#

# Remember old saved bookmarks as DB_<bookmark>:
# Thanks for the suggestion to Jason Priebe (jpriebe@cbcnewmedia.com)
[ -e ~/.bashDirB_envvars ] && source ~/.bashDirB_envvars

# If the repository of bookmarks does not exist, create it
[ ! -e ~/.DirB ] && mkdir ~/.DirB

function h() {        # Thanks to Manuel Soriano manu@manu.ms
  cat <<\EOF
OPERATIONS

  s       Save a directory bookmark
  g       go to a bookmark or named directory
  p       push a bookmark/directory onto the dir stack
  r       remove saved bookmark
  d       display bookmarked directory path
  sl      print the list of directory bookmarks

EXAMPLES

  s xyz                  current directory is saved as xyz
  s xyz ../../dir0/dir1  save relative directory as xyz
  s xyz dir notes here   save directory with comments
  g xyz                  go to bookmark xyz or to path xyz
  p xyz                  go to bookmark/directory xyz
                         and remember into the directory stack
  p                      swap to two bookmarks
  p +n                   rotate nth entry from top to top
  p -n                   rotate nth entry from bottm to top
  r xyz                  remove named bookmark
  d xyz                  display directory name of bookmark xyz
  sl -l                  long list
  sl -p                  path list
  sl "*x"                list all of all bookmarks *x
  sl -l "*x"             long list all of all bookmarks *x
EOF
}

# "s" - Save bookmark
function s() {
  # build the bookmark file with the contents "$CD directory_path"
  if [ -n "$2" ]; then
    ( echo '$CD ' \"$2\" > ~/.DirB/"$1" ;) > /dev/null 2>&1
  else
    ( echo -n '$CD ' > ~/.DirB/"$1" ;
    pwd \
    | sed "s/ /\\\\ /g" >> ~/.DirB/"$1" ; ) > /dev/null 2>&1
  fi

  # if the bookmark could not be created, print an error message and
  # exit with a failing return code
  if [ $? != 0 ]; then
    echo >&2 "bash: DirB: ~/.DirB/$1 could not be created"
    false
  fi

  echo export db_$1=\'$(d "$1")\' >> ~/.bashDirB_envvars
  . ~/.bashDirB_envvars

  NAME="$1"
  shift; shift
  if [ -n "$1" ]; then
    ( echo "echo $*" >> ~/.DirB/"$NAME" ;) > /dev/null 2>&1
  fi
}

# "g" - Go to bookmark
function g() {
  # if no arguments, then just go to the home directory
  if [ -z "$1" ]; then
    cd
  else
    # if $1 is in ~/.DirB and does not begin with ".", then go to it
    # update the bookmark's timestamp and then execute it
    # else just do a "cd" to the argument, usually a directory path of "-"
    if [ -f ~/.DirB/"$1" -a ${1:0:1} != "." ]; then
      touch ~/.DirB/"$1" ;
      CD=cd source ~/.DirB/"$1" ;
    else
      cd "$1"
    fi
  fi
}

# "p" - Push a bookmark
# Note, the author's preference is to list the directory stack in a single
# column.  Thus, the standard behavior of "pushd" and "popd" have been
# replaced by discarding the normal output of these commands and using a
# "dirs -p" after each one.
function p() {
  # if no argument given, then just pushd and print out the directory stack
  # if $1 is a dash, then just do a "popd" and print out the directory stack
  if [ -z "$1" ]; then
    pushd > /dev/null && dirs -p
  elif [ "$1" == "-" ]; then
    popd > /dev/null
    dirs -p
  else
    # if $1 is in ~/.DirB and does not begin with ".", then go to it
    # and then print out the directory stack
    # else just do a "pushd" and print out the directory stack
    if [ -f ~/.DirB/"$1" -a "${1:0:1}" != "." ]; then
      touch ~/.DirB/$1 ;
      CD=pushd source ~/.DirB/$1 > /dev/null \
        && dirs -p ;
    else
      pushd "$1" > /dev/null && dirs -p
    fi
  fi
}

# "sl" - Saved bookmark Listing
# if the "-l" argument is given, then do a long listing, passing any
# remaining arguments to "ls", printing in reverse time order.  Pass the
# output to "less" to page the output if longer than a screen in length.
#
# if the "-p" argument is given, list the directory bookmarks and the paths
# that they point to.  (Thanks to Francis Hulin-Hubard fhh@admin-linux.fr)
function sl() {
  if [ "$1" == "-l" ]; then
    shift
    ( cd ~/.DirB ;
      ls -lt -- $* 2>/dev/null \
      | sed -e 's/  */ /g' \
            -e '/^total/d' \
            -e 's/^\(... \)\([0-9] \)/\1 \2/' \
      | cut -d ' ' -s -f6- \
      | sed -e '/ [0-9] /s// &/' \
      | less -FX ; \
    )
  elif [ "$1" == "-p" ]; then
    shift
    ( cd ~/.DirB ; \
      for i in $(ls -- $* 2>/dev/null); do echo "$i: $(d $i)"; done \
    ) \
    | less -FX
  else
    ( cd ~/.DirB ; ls -xt $* ; )
  fi
}

# "r" - Remove a saved bookmark
function r() {
  # if the bookmark file exists, remove it
  # if the bookmark file does not exist, complain and exit with a failing code
  if [ -e ~/.DirB/"$1" ]; then
    rm ~/.DirB/"$1"
    sed \
      -i_bak ~/.bashDirB_envvars \
      -e "/export db_$1=/d" > /dev/null 2>&1
  else
    echo >&2 "bash: DirB: ~/.DirB/$1 does not exist"
    false
  fi
}

# "d" - Display (or Dereference) a saved bookmark
# to use: cd "$(d xxx)"
function d() {
  # if the bookmark exists, then extract its directory path and print it
  # if the bookmark does not exists, complain and exit with a failing code
  if [ -e ~/.DirB/"$1" ]; then
    head -1 ~/.DirB/"$1" \
    | sed \
        -e 's/\$CD //' \
        -e 's/\\//g'
  else
    echo >&2 "bash: DirB: ~/.DirB/$1 does not exist"
    false
  fi
}