go version script

gv.sh

#!/usr/bin/env bash
function _current_version() {
  #echo ${v#go};
  local current=`go version | { read _ _ v _; echo ${v#go}; }`
  echo $current
}
function _change_symlink() {
  if [ -z "$1" ]; then
    echo "no version passed in"
    return
  fi
  local version=$version
  local match=$(ls "$GOPATH/bin" | sort -nr | grep "$version" | head -n 1 | grep "$version")
  echo $match
  ln -sf $GOPATH/bin/$match /usr/local/bin/go && go version
}

function _list_installed() {
  local results=($(ls $GOPATH/bin | sort | grep "go[0-9].[0-9]*[.0-9]*" | tr -s "\n"))
  local current=$(_current_version)
  for v in $results
  do
    if [ "${v#go}" = "$current" ]; then
    echo "${v#go} *"
else
    echo "${v#go}"
fi
  done
}
function _install() {
  if [ -z "$1" ]; then
    echo "no version passed in"
    return
  fi
  local version=$1
  echo "go $version downloading ..."
  go install golang.org/dl/go$version@latest && go$version download && echo "go $version downloaded"
}

function _remove() {
  if [ -z "$1" ]; then
    echo "no version passed in"
    return
  fi
  local version=$1
  local vpath=$(go$version env GOROOT)
  rm "$GOPATH/bin/go$version" && rm -rf $vpath && echo "go $version removed"
}

function gv() {
  if [ -z "$GOPATH" ]; then
    echo 'ERROR: GOPATH is not set! Please add the following line to your .zlogin'
	  exit 1
  fi
  
  local command=$1
  local version=$2
  if [[ $command == "use" ]]; then
    _change_symlink $version
  elif [[ $command == "list" ]]; then
    _list_installed
  elif [[ $command == "install" ]]; then
    _install $version
  elif [[ $command == "remove" ]]; then
    _remove $version
  elif [[ $command == "current" ]]; then
    _current_version
  else
    		echo "Usage: gv [command]
Description:
  gv is my Go Version Manager
Commands:
  use        - select a go version to use
  list       - list installed versions
  install    - install go version
  remove     - uninstall go version
"
  fi
}