TranslateProject/sources/tech/20200107 Introduction to the Linux goto shell utility.md

Introduction to the Linux goto shell utility

Learn how to use goto to alias and navigate to directories with autocomplete in Linux. ![Files in a folder][1]

The goto shell utility allows users to navigate to aliased directories and also supports autocompletion.

How it works

Before you can use goto, you need to register your directory aliases. For example:

`goto -r dev /home/iridakos/development`

then change to that directory, e.g.:

`goto dev`

![goto demo][2]

Autocompletion in goto

goto comes with a nice autocompletion script—whenever you press the Tab key after the goto command, Bash or Zsh will prompt you with suggestions of the aliases that are available:

$ goto <tab>
bc /etc/bash_completion.d                    
dev /home/iridakos/development
rubies /home/iridakos/.rvm/rubies

Installing goto

There are several ways to install goto.

Via script

Clone the repository and run the install script as a superuser or root:

git clone <https://github.com/iridakos/goto.git>
cd goto
sudo ./install

Manually

Copy the file goto.sh somewhere in your filesystem and add a line in your .zshrc or .bashrc to source it.

For example, if you placed the file in your home folder, all you have to do is add the following line to your .zshrc or .bashrc file:

`source ~/goto.sh`

MacOS Homebrew

A formula named goto is available for the Bash shell in MacOS:

`brew install goto`

Add colored output

`echo -e "\$include /etc/inputrc\nset colored-completion-prefix on" >> ~/.inputrc`

Notes:

• You need to restart your shell after installation.
• You need to have the Bash completion feature enabled for Bash in MacOS (see this [issue][3]).
  • You can install it with brew install bash-completion if you don't have it enabled.

Ways to use goto

Change to an aliased directory

To change to an aliased directory, type:

`goto <alias>`

For example:

`goto dev`

Register an alias

To register a directory alias, type:

`goto -r <alias> <directory>`

or

`goto --register <alias> <directory>`

For example:

`goto -r blog /mnt/external/projects/html/blog`

or

`goto --register blog /mnt/external/projects/html/blog`

Notes:

• goto expands the directories, so you can easily alias your current directory with the following command and it will automatically be aliased to the whole path: [code]goto -r last_release .

  * Pressing the Tab key after the alias name provides the shell's default directory suggestions.



### Unregister an alias

To unregister an alias, use:

goto -u <alias>

or

goto --unregister <alias>

For example:

goto -u last_release

or

goto --unregister last_release

**Note:** By pressing the Tab key after the command (**-u** or **\--unregister**), the completion script will prompt you with the list of registered aliases.

### List aliases

To get a list of your currently registered aliases, use:

goto -l

or

goto --list

### Expand an alias

To expand an alias to its value, use:

goto -x <alias>

or

goto --expand <alias>

For example:

goto -x last_release

or

goto --expand last_release

### Clean up aliases

To clean up the aliases from directories that are no longer accessible in your filesystem, use:

goto -c

or

goto --cleanup

### Get help

To view the tool's help information, use:

goto -h

or

goto --help

### Check the version

To view the tool's version, use:

goto -v

or

goto --version

### Push before changing directories

To push the current directory onto the directory stack before changing directories, type:

goto -p <alias>

or

goto --push <alias>

### Revert to a pushed directory

To return to a pushed directory, type:

goto -o

or

goto --pop

**Note:** This command is equivalent to **popd** but within the **goto** command.

## Troubleshooting

If you see the error **command not found: compdef** in Zsh, it means you need to load **bashcompinit**. To do so, append this to your **.zshrc** file:

autoload bashcompinit bashcompinit

## Get involved

The goto tool is open source under the [MIT License][4] terms, and contributions are welcomed. To learn more, visit the [Contributing][5] section in goto's GitHub repository.

## The goto script

goto() {   local target   _goto_resolve_db

  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 "$@"       ;;     -p|--push) # Push the current directory onto the pushd stack, then goto       _goto_directory_push "$@"       ;;     -o|--pop) # Pop the top directory off of the pushd stack, then change that directory       _goto_directory_pop       ;;     -l|--list)       _goto_list_aliases       ;;     -x|--expand) # Expand an alias       _goto_expand_alias "$@"       ;;     -h|--help)       _goto_usage       ;;     -v|--version)       _goto_version       ;;     *)       _goto_directory "$subcommand"       ;;   esac   return $? }

_goto_resolve_db() {   GOTO_DB="${GOTO_DB:-$HOME/.goto}"   touch -a "$GOTO_DB" }

_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>   -p, --push: pushes the current directory onto the stack, then performs goto     goto -p|--push <alias>   -o, --pop: pops the top directory from the stack, then changes to that directory     goto -o|--pop   -l, --list: lists aliases     goto -l|--list   -x, --expand: expands an alias     goto -x|--expand <alias>   -c, --cleanup: cleans up non existent directory aliases     goto -c|--cleanup   -h, --help: prints this help     goto -h|--help   -v, --version: displays the version of the goto script     goto -v|--version USAGE }

Displays version

_goto_version() {   echo "goto version 1.2.4.1" }

Expands directory.

Helpful for ~, ., .. paths

_goto_expand_directory() {   builtin cd "$1" 2>/dev/null && pwd }

Lists registered aliases.

_goto_list_aliases() {   local IFS=$' '   if [ -f "$GOTO_DB" ]; then     while read -r name directory; do       printf '\e[1;36m%20s  \e[0m%s\n' "$name" "$directory"     done < "$GOTO_DB"   else     echo "You haven't configured any directory aliases yet."   fi }

Expands a registered alias.

_goto_expand_alias() {   if [ "$#" -ne "1" ]; then     _goto_error "usage: goto -x|--expand <alias>"     return   fi

  local resolved

  resolved=$(_goto_find_alias_directory "$1")   if [ -z "$resolved" ]; then     _goto_error "alias '$1' does not exist"     return   fi

  echo "$resolved" }

Lists duplicate directory aliases

_goto_find_duplicate() {   local duplicates=

  duplicates=$(sed -n 's:[^ ]* '"1"':&:p' "$GOTO_DB" 2>/dev/null)   echo "$duplicates" }

Registers and alias.

_goto_register_alias() {   if [ "$#" -ne "2" ]; then     _goto_error "usage: goto -r|--register <alias> <directory>"     return 1   fi

  if ! [[ 1 =~ ^[[:alnum:]]+[a-zA-Z0-9_-]* ]]; then     _goto_error "invalid alias - can start with letters or digits followed by letters, digits, hyphens or underscores"     return 1   fi

  local resolved   resolved=$(_goto_find_alias_directory "$1")

  if [ -n "$resolved" ]; then     _goto_error "alias '$1' exists"     return 1   fi

  local directory   directory=$(_goto_expand_directory "$2")   if [ -z "$directory" ]; then     _goto_error "failed to register '$1' to '$2' - can't cd to directory"     return 1   fi

  local duplicate   duplicate=$(_goto_find_duplicate "$directory")   if [ -n "$duplicate" ]; then     _goto_warning "duplicate alias(es) found: \\n$duplicate"   fi

  # Append entry to file.   echo "$1 $directory" >> "$GOTO_DB"   echo "Alias '$1' registered successfully." }

Unregisters the given alias.

_goto_unregister_alias() {   if [ "$#" -ne "1" ]; then     _goto_error "usage: goto -u|--unregister <alias>"     return 1   fi

  local resolved   resolved=$(_goto_find_alias_directory "$1")   if [ -z "$resolved" ]; then     _goto_error "alias '$1' does not exist"     return 1   fi

  # shellcheck disable=SC2034   local readonly GOTO_DB_TMP="$HOME/.goto_"   # Delete entry from file.   sed "/^$1 /d" "$GOTO_DB" > "$GOTO_DB_TMP" && mv "$GOTO_DB_TMP" "$GOTO_DB"   echo "Alias '$1' unregistered successfully." }

Pushes the current directory onto the stack, then goto

_goto_directory_push() {   if [ "$#" -ne "1" ]; then     _goto_error "usage: goto -p|--push <alias>"     return   fi

  { pushd . || return; } 1>/dev/null 2>&1

  _goto_directory "$@" }

Pops the top directory from the stack, then goto

_goto_directory_pop() {   { popd || return; } 1>/dev/null 2>&1 }

Unregisters aliases whose directories no longer exist.

_goto_cleanup() {   if ! [ -f "$GOTO_DB" ]; then     return   fi

  while IFS= read -r i && [ -n "$i" ]; do     echo "Cleaning up: $i"     _goto_unregister_alias "$i"   done <<< "$(awk '{al=$1; $1=""; dir=substr($0,2);                     system("[ ! -d "" dir "" ] && echo " al)}' "$GOTO_DB")" }

Changes to the given alias' directory

_goto_directory() {   local target

  target=$(_goto_resolve_alias "$1") || return 1

  builtin cd "$target" 2> /dev/null ||
    { _goto_error "Failed to goto '$target'" && return 1; } }

Fetches the alias directory.

_goto_find_alias_directory() {   local resolved

  resolved=$(sed -n "s/^$1 \\(.*\\)/\\1/p" "$GOTO_DB" 2>/dev/null)   echo "$resolved" }

Displays the given error.

Used for common error output.

_goto_error() {   (>&2 echo -e "goto error: $1") }

Displays the given warning.

Used for common warning output.

_goto_warning() {   (>&2 echo -e "goto warning: $1") }

Displays entries with aliases starting as the given one.

_goto_print_similar() {   local similar

  similar=$(sed -n "/^$1[^ ]* .*/p" "$GOTO_DB" 2>/dev/null)   if [ -n "$similar" ]; then     (>&2 echo "Did you mean:")     (>&2 column -t <<< "$similar")   fi }

Fetches alias directory, errors if it doesn't exist.

_goto_resolve_alias() {   local resolved

  resolved=$(_goto_find_alias_directory "$1")

  if [ -z "$resolved" ]; then     _goto_error "unregistered alias $1"     _goto_print_similar "$1"     return 1   else     echo "${resolved}"   fi }

Completes the goto function with the available commands

_complete_goto_commands() {   local IFS=$' \t\n'

  # shellcheck disable=SC2207   COMPREPLY=($(compgen -W "-r --register -u --unregister -p --push -o --pop -l --list -x --expand -c --cleanup -v --version" -- "$1")) }

Completes the goto function with the available aliases

_complete_goto_aliases() {   local IFS=$'\n' matches   _goto_resolve_db

  # shellcheck disable=SC2207   matches=($(sed -n "/^$1/p" "$GOTO_DB" 2>/dev/null))

  if [ "${#matches[@]}" -eq "1" ]; then     # remove the filenames attribute from the completion method     compopt +o filenames 2>/dev/null

    # if you find only one alias don't append the directory     COMPREPLY=("${matches[0]// *}")   else     for i in "${!matches[@]}"; do       # remove the filenames attribute from the completion method       compopt +o filenames 2>/dev/null

      if ! ; then         matches[$i]=$(printf '%*s' "-$COLUMNS" "${matches[$i]}")

        COMPREPLY+=("$(compgen -W "${matches[$i]}")")       els