README: add zsh usage

darwin: load into agent keys stored in keychain

Author: msimerson

Changes.md

@@ -1,6 +1,11 @@
 
 # VERSION - CHANGES
 
+### 1.06 - Nov 27, 2019
+
+* SC2086, quote strings
+* Update README with zsh instructions
+
 ### 1.05 - Nov 12, 2013
 
 * use TMPDIR if defined, default to /tmp (was hard coded /tmp)
@@ -16,10 +21,9 @@
 
 ### 1.02 - Dec 16, 2007
 
-* adjusted ps invocation for reliable detection when multiple 
-* users run ssh-agent on a single system
+* adjusted ps invocation for reliable detection when multiple users run ssh-agent on a single system
 
-### 1.01 - Oct 9, 2007 
+### 1.01 - Oct 9, 2007
 
 * when cleaning up stale agent, remove stale sock file
 

README.md

@@ -1,6 +1,6 @@
 # ssh-agent
 
-A bash script that autoloads the ssh-agent and keys into each terminal session
+A shell script that autoloads the ssh-agent and keys into each terminal session
 of a workstation, significantly reducing the complexity of using ssh-agent.
 
 Used and tested on Mac OS X, FreeBSD, and Linux computers. Should work on any
@@ -10,12 +10,20 @@ UNIXy host with OpenSSH installed.
 
 1. Install to $HOME/.ssh directory as agent.sh
 
-  curl -L -o .ssh/agent.sh https://github.com/msimerson/ssh-agent/raw/master/agent.sh
-  chmod 755 .ssh/agent.sh
+```sh
+curl -L -o ~/.ssh/agent.sh https://github.com/msimerson/ssh-agent/raw/master/agent.sh
+chmod 755 ~/.ssh/agent.sh
+```
 
 2. Run it when new terminal windows open
 
-  echo 'source .ssh/agent.sh' >> ~/.bash\_profile
+### bash
+
+ `echo 'source .ssh/agent.sh' >> ~/.bash\_profile`
+
+### zsh
+
+ `echo '.ssh/agent.sh' >> ~/.zprofile`
 
 3. Open new terminal/shell sessions
 

agent.sh

@@ -25,7 +25,19 @@ TMPDIR=${1-/tmp}
 # See README file, SSH-AGENT SOCKET note
 _sockfile="${HOME}/.ssh/agent.sock"
 
-if [ "$0" != "-bash" ] && [ "$0" != "-zsh" ];
+is_login_shell_bash()
+{
+ expr "$SHELL" : '.*bash' >> /dev/null
+ if [ $? -eq 0 ]; then
+ # echo "yes"
+ return 0
+ else
+ # echo "no"
+ return 1
+ fi
+}
+
+if is_login_shell_bash && [ "$0" != "-bash" ];
 then
  echo '
 OOPS! Did you mean to source this script? Try this:
@@ -34,9 +46,9 @@ OOPS! Did you mean to source this script? Try this:
 '
 fi
 
-if [ ! -z "$_sockfile" ];
+if [ -n "$_sockfile" ];
 then
- _agent_opts="-a $_sockfile $_agent_opts"
+ _agent_opts="-s -a $_sockfile $_agent_opts"
 fi
 
 main()
@@ -66,6 +78,7 @@ main()
  then
  echo "ssh-agent socket is stale"
  kill "${_agent_pid}" # kill ssh-agent
+ killall pgrep ssh-agent -U "$USER"
  cleanup_stale_agent
  start_ssh_agent
  return
@@ -74,18 +87,16 @@ main()
 
 set_agent_pid()
 {
- #echo "checking for ssh-agent process"
- _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 $2 }' | tail -n1)
+ # echo "checking for ssh-agent process"
+ _agent_pid=$(pgrep -U "$USER" ssh-agent | 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)
+ _sock_pid=$(echo "${_agent_pid}" - 1 | bc)
  _sockfile=$(/bin/ls "$TMPDIR/ssh-*/agent.${_sock_pid}")
  fi
 
@@ -122,14 +133,19 @@ discover_ssh_agent()
 start_ssh_agent()
 {
  echo "starting ssh-agent $_agent_opts"
- ssh-agent $_agent_opts > /dev/null
+ # shellcheck disable=SC2046,SC2086
+ eval $(ssh-agent $_agent_opts) || return
 
  discover_ssh_agent
 
- if [ ! -z "$SSH_AUTH_SOCK" ];
+ if [ -n "$SSH_AUTH_SOCK" ];
  then
- # this will prompt the user to authenticate their ssh key(s)
  echo "adding ssh key(s) to agent"
+ if [ "$(uname)" = "Darwin" ]; then
+ # loads SSH keys stored in OS X Keychain
+ ssh-add -A
+ fi
+ # this will prompt the user to authenticate their password protected ssh key(s)
  ssh-add
  fi
 }