shellcheck: quote variable strings

Author: msimerson

agent.sh

@@ -25,7 +25,7 @@ TMPDIR=${1-/tmp}
 # See README file, SSH-AGENT SOCKET note
 _sockfile="${HOME}/.ssh/agent.sock"
 
-if [ "$0" != "-bash" ];
+if [ "$0" != "-bash" ] && [ "$0" != "-zsh" ];
 then
  echo '
 OOPS! Did you mean to source this script? Try this:
@@ -43,18 +43,18 @@ main()
 {
  discover_ssh_agent
 
-#  1. ssh-agent not running.
+ # 1. ssh-agent not running.
  if [ -z "${_agent_pid}" ];
  then
  cleanup_stale_agent
  start_ssh_agent
  return
  fi
 
-#  2. ssh-agent is running but...
-#
-#   SSH_AGENT_PID is set but different than running ssh-agent pid
- if [ ! -z $SSH_AGENT_PID ] && [ $SSH_AGENT_PID -ne "${_agent_pid}" ];
+ # 2. ssh-agent is running but...
+ #
+ # SSH_AGENT_PID is set but different than running ssh-agent pid
+ if [ ! -z "$SSH_AGENT_PID" ] && [ "$SSH_AGENT_PID" -ne "${_agent_pid}" ];
  then
  cleanup_stale_agent
  discover_ssh_agent
@@ -65,7 +65,7 @@ main()
  if [ $? -eq 2 ]; # communication failed
  then
  echo "ssh-agent socket is stale"
- kill ${_agent_pid} # kill ssh-agent
+ kill "${_agent_pid}" # kill ssh-agent
  cleanup_stale_agent
  start_ssh_agent
  return
@@ -74,18 +74,19 @@ main()
 
 set_agent_pid()
 {
- # this is expensive but reliable
  #echo "checking for ssh-agent process"
- _agent_pid=`ps uwwxU $USER | grep ssh-agent | grep -v grep | awk '{ print $2 }' | tail -n1`
+ _agent_pid=$(pgrep -U "$USER" ssh-agent)
+ # this is expensive but reliable
+ #_agent_pid=$(ps uwwxU "$USER" | grep ssh-agent | grep -v grep | awk '{ print $2 }' | tail -n1)
 }
 
 set_socket_file()
 {
  # if _sockfile is not defined we must figure it out
  if [ -z "$_sockfile" ] || [ ! -e "$_sockfile" ];
  then
- _sock_pid=`echo "${_agent_pid} - 1" | bc`
- _sockfile=`/bin/ls $TMPDIR/ssh-*/agent.${_sock_pid}`
+ _sock_pid=$(echo "${_agent_pid} - 1" | bc)
+ _sockfile=$(/bin/ls "$TMPDIR/ssh-*/agent.${_sock_pid}")
  fi
 
  if [ ! -e "$_sockfile" ];
@@ -101,19 +102,19 @@ discover_ssh_agent()
 {
  set_agent_pid
 
- if [ -z $_agent_pid ]; # no agent PID discovered
+ if [ -z "$_agent_pid" ]; # no agent PID discovered
  then
  echo "ssh agent is not running"
  return
  fi
 
  echo "ssh agent for $USER found at pid ${_agent_pid}."
- export SSH_AGENT_PID=${_agent_pid}
+ export SSH_AGENT_PID="${_agent_pid}"
 
  set_socket_file
 
  # make sure the Mac Login environment is configured
- if [ "`uname`" == "Darwin" ]; then
+ if [ "$(uname)" = "Darwin" ]; then
  setup_plist
  fi
 }
@@ -125,7 +126,7 @@ start_ssh_agent()
 
  discover_ssh_agent
 
- if [ ! -z $SSH_AUTH_SOCK ];
+ if [ ! -z "$SSH_AUTH_SOCK" ];
  then
  # this will prompt the user to authenticate their ssh key(s)
  echo "adding ssh key(s) to agent"
@@ -137,15 +138,15 @@ setup_plist()
 {
  _envdir="$HOME/.MacOSX"
 
- if [ ! -d $_envdir ]; then
- mkdir $_envdir
+ if [ ! -d "$_envdir" ]; then
+ mkdir "$_envdir"
  fi
 
  _plist="$_envdir/environment.plist"
 
- if [ -e $_plist ];
+ if [ -e "$_plist" ];
  then
- grep -q $_sockfile $_plist
+ grep -q "$_sockfile" "$_plist"
  ENVSET=$?
  if [ ! $ENVSET ]; then
  set +o noclobber
@@ -171,29 +172,29 @@ write_plist()
  </dict>
 </plist>
 EOXML
- ) > $_plist
+ ) > "$_plist"
 }
 
 cleanup_stale_agent()
 {
  # check the environment variable SSH_AGENT_PID as it could be set
  # despite the ssh-agent process being missing.
- if [ ! -z $SSH_AGENT_PID ];
+ if [ ! -z "$SSH_AGENT_PID" ];
  then
  echo "cleaning stale SSH_AGENT_PID: $SSH_AGENT_PID"
  unset SSH_AGENT_PID
  fi
 
- if [ ! -z $SSH_AUTH_SOCK ];
+ if [ ! -z "$SSH_AUTH_SOCK" ];
  then
  echo "cleaning stale SSH_AUTH_SOCK"
  unset SSH_AUTH_SOCK
  fi
 
- if [ -e $_sockfile ];
+ if [ -e "$_sockfile" ];
  then
  echo "removing stale socket file: $_sockfile"
- unlink $_sockfile
+ unlink "$_sockfile"
  fi
 }