First take on the goto bash utility.

README.md

@@ -1,2 +1,146 @@
 # goto
-[wip]
+
+`goto` is a bash utility allowing users to change faster to frequently visited **aliased** directories
+
+# How does it work?
+
+User registers directory aliases, for example:
+```bash
+goto -r dev /home/iridakos/development
+```
+and then `cd`s to that directory with:
+```bash
+goto dev
+```
+
+![goto demo gif](https://github.com/iridakos/goto/raw/master/doc/goto.gif)
+
+# goto completion
+
+`goto` comes with a nice auto-completion script so that whenever you press the `tab` key after the `goto` command, bash prompts with suggestions of the available aliases:
+
+```bash
+bc /etc/bash_completion.d                     
+dev /home/iridakos/development
+rubies /home/iridakos/.rvm/rubies
+```
+
+# Installation
+
+Copy the file `goto.bash` somewhere in your filesystem and add a line to source it your `.bashrc`.
+
+For example, if you placed the file in your home folder, all you have to do is add the following line to your `.bashrc` file:
+
+```bash
+source ~/goto.bash
+```
+
+# Usage
+
+## Change to an aliased directory
+To change to an aliased directory, type:
+```bash
+goto <alias>
+```
+
+### Example:
+```bash
+goto dev
+```
+
+## Register an alias
+To register a directory alias, type:
+```bash
+goto -r <alias> <directory>
+```
+or
+```bash
+goto --register <alias> <directory>
+```
+
+### Example:
+```bash
+goto -r blog /mnt/external/projects/html/blog
+```
+or
+```bash
+goto --register blog /mnt/external/projects/html/blog
+```
+
+### Notes
+
+* `goto` **expands** the directories hence you can easily alias your current directory with:
+```bash
+goto -r last_release .
+```
+and it will automatically be aliased to the whole path.
+* Pressing the `tab` key after the alias name, you have the default directory suggestions by bash.
+
+## Unregister an alias
+
+To unregister an alias, use:
+```bash
+goto -u <alias>
+```
+or
+```bash
+goto --unregister <alias>
+```
+### Example
+```
+goto -u last_release
+```
+or
+```
+goto --unregister last_release
+```
+
+### Notes
+
+Pressing the `tab` key after the command (`-u` or `--unregister`), the completion script will prompt you with the list of registered aliases for your convenience.
+
+## List aliases
+
+To get the list of your currently registered aliases, use:
+```bash
+goto -l
+```
+or
+```bash
+goto --list
+```
+
+## Cleanup
+
+To cleanup the aliases from directories that are no longer accessible in your filesystem, use:
+
+```bash
+goto -c
+```
+or
+```bash
+goto --cleanup
+```
+
+## Help
+
+To view the tool's help information, use:
+```bash
+goto -h
+```
+or
+```bash
+goto --help
+```
+
+## Contributing
+
+1. Fork it ( https://github.com/iridakos/goto/fork )
+2. Create your feature branch (`git checkout -b my-new-feature`)
+3. Commit your changes (`git commit -am 'Add some feature'`)
+4. Push to the branch (`git push origin my-new-feature`)
+5. Create a new Pull Request
+
+## License
+
+This tool is open source under the [MIT License](https://opensource.org/licenses/MIT) terms.

goto.bash

@@ -0,0 +1,260 @@
+#!/usr/bin/env bash
+# MIT License
+#
+# Copyright (c) 2018 Lazarus Lazaridis
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in all
+# copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+# SOFTWARE.
+
+# Changes to the given alias directory
+# or executes a command based on the arguments.
+function goto()
+{
+  local target
+
+  if [ -z "$1" ]; then
+    # display usage and exit when no args
+    _goto_usage
+    return
+  fi
+
+  subcommand="$1"
+  shift
+  case "$subcommand" in
+    -c|--cleanup)
+      _goto_cleanup "$@"
+      ;;
+    -r|--register) # Register an alias
+      _goto_register_alias "$@"
+      ;;
+    -u|--unregister) # Unregister an alias
+      _goto_unregister_alias "$@"
+      ;;
+    -l|--list)
+      _goto_list_aliases
+      ;;
+    -h|--help)
+      _goto_usage
+      ;;
+    *)
+      _goto_directory "$subcommand"
+      ;;
+  esac
+}
+
+function _goto_usage()
+{
+  cat <<\USAGE
+usage: goto [<option>] <alias> [<directory>]
+default usage:
+  goto <alias> - changes to the directory registered for the given alias
+OPTIONS:
+  -r, --register: registers an alias
+    goto -r|--register <alias> <directory>
+  -u, --unregister: unregisters an alias
+    goto -u|--unregister <alias>
+  -l, --list: lists aliases
+    goto -l|--list
+  -c, --cleanup: cleans up non existent directory aliases
+    goto -c|--cleanup
+  -h, --help: prints this help
+    goto -h|--help
+USAGE
+}
+
+# Expands directory.
+# Helpful for ~, ., .. paths
+function _goto_expand_directory()
+{
+  printf "$(cd $1 2>/dev/null && pwd)"
+}
+
+# Lists regstered aliases.
+function _goto_list_aliases()
+{
+    local IFS=$'\n'
+    echo "$(sed '/^\s*$/d' ~/.goto)"
+}
+
+# Registers and alias.
+function _goto_register_alias()
+{
+  if [ "$#" -ne "2" ]; then
+    _goto_error "usage: goto -r|--register <alias> <directory>"
+    return
+  fi
+
+  if ! [[ $1 =~ ^[[:alnum:]]*[[:alpha:]][[:alnum:]]*$ ]]; then
+    _goto_error "invalid alias - only alphabetic with numbers"
+    return
+  fi
+
+  local resolved=$(_goto_find_alias_directory $1)
+  if [ -n "$resolved" ]; then
+    _goto_error "alias '$1' exists"
+    return
+  fi
+
+  local directory="$(_goto_expand_directory $2)"
+  if [ -z "$directory" ]; then
+    _goto_error "failed to register $1 to $2 - can't cd to directory"
+    return
+  fi
+
+  # Append entry to file.
+  echo "$1 $directory" >> ~/.goto
+  echo "Alias '$1' registered successfully."
+}
+
+# Unregisters the given alias.
+function _goto_unregister_alias
+{
+  if [ "$#" -ne "1" ]; then
+    _goto_error "usage: goto -u|--unregister <alias>"
+    return
+  fi
+
+  local resolved=$(_goto_find_alias_directory $1)
+  if [ -z "$resolved" ]; then
+    _goto_error "alias '$1' does not exist"
+    return
+  fi
+
+  # Delete entry from file.
+  echo "$(sed "/^\<$1\>/d" ~/.goto)" > ~/.goto
+  echo "Alias '$1' unregistered successfully."
+}
+
+# Unregisters aliases whose directories no longer exist.
+function _goto_cleanup()
+{
+  sed '/^\s*$/d' ~/.goto
+  while IFS='' read -r entry || [[ -n "$entry" ]]; do
+    al=$(echo $entry | sed 's/[\t ].*//')
+    dir=$(echo $entry | sed 's/[^ ]* //')
+
+    if [ -n "$al" ] && [ ! -d "$dir" ]; then
+      echo "Cleaning up: $al - $dir"
+      _goto_unregister_alias $al
+    fi
+  done <<< "$(cat ~/.goto 2>/dev/null)"
+}
+
+# Changes to the given alias' directory
+function _goto_directory()
+{
+  local target=$(_goto_resolve_alias "$1")
+
+  if [ -n "$target" ]; then
+    cd "$target"
+  fi
+}
+
+# Fetches the alias directory.
+function _goto_find_alias_directory()
+{
+  local resolved=$(sed -n "/^\<$1\>/p" ~/.goto 2>/dev/null | sed 's/[^ ]* //')
+  echo "$resolved"
+}
+
+# Displays the given error.
+# Used for common error output.
+function _goto_error()
+{
+  (>&2 echo "goto error: $1")
+}
+
+# Fetches alias directory, errors if it doesn't exist.
+function _goto_resolve_alias()
+{
+  local resolved=$(_goto_find_alias_directory "$1")
+  if [ -z "$resolved" ]; then
+    _goto_error "unregistered alias $1"
+    echo ""
+  else
+    echo "${resolved}"
+  fi
+}
+
+# Completes the goto function with the available commands
+function _complete_goto_commands()
+{
+  COMPREPLY=($(compgen -W "-r --register -u --unregister -l --list" -- "$1"))
+}
+
+# Completes the goto function with the available aliases
+function _complete_goto_aliases()
+{
+  local IFS=$'\n' expr
+
+  local matches=($(sed  -n "/^$1/p" ~/.goto 2>/dev/null))
+
+  if [ "${#matches[@]}" -eq "1" ]; then
+    # remove the filenames attribute from the completion method
+    compopt +o filenames
+
+    # if you find only one alias don't append the directory
+    COMPREPLY=$(printf ${matches[0]} | sed 's/[\t ].*//')
+  else
+    for i in "${!matches[@]}"; do
+      # remove the filenames attribute from the completion method
+      compopt +o filenames
+
+      matches[$i]="$(echo ${matches[$i]} | sed 's/[\t]/ /g')"
+      matches[$i]=$(printf '%*s' "-$COLUMNS"  "${matches[$i]}")
+
+      COMPREPLY+=($(compgen -W "${matches[$i]}"))
+    done
+  fi
+}
+
+# Bash programmable completion for the goto function
+function _complete_goto()
+{
+  local cur="${COMP_WORDS[$COMP_CWORD]}"
+
+  if [ "$COMP_CWORD" -eq "1" ]; then
+    # if we are on the first argument
+    if [[ $cur == -* ]]; then
+      # and starts like a command, prompt commands
+      _complete_goto_commands "$cur"
+    else
+      # and doesn't start as a command, prompt aliases
+      _complete_goto_aliases "$cur"
+    fi
+  elif [ "$COMP_CWORD" -eq "2" ]; then
+    # if we are on the second argument
+    local prev="${COMP_WORDS[1]}"
+
+    if [[ $prev = "-u" ]] || [[ $prev = "--unregister" ]]; then
+      # prompt with aliases only if user tries to unregister one
+      _complete_goto_aliases "$cur"
+    fi
+  elif [ "$COMP_CWORD" -eq "3" ]; then
+    # if we are on the third argument
+    local prev="${COMP_WORDS[1]}"
+
+    if [[ $prev = "-r" ]] || [[ $prev = "--register" ]]; then
+      # prompt with directories only if user tries to register an alias
+      COMPREPLY=($(compgen -d -- "$cur"))
+    fi
+  fi
+}
+
+# Register the goto compspec
+complete -o filenames -F _complete_goto goto