mdw@git.distorted.org.uk Git - profile/blob - bin/start-ssh-agent

   1 #! /bin/sh
   2
   3 set -e
   4 usage="Usage: $0 [-bc] [COMMAND [ARGS...]]"
   5
   6 ### Parse options
   7 case "${SHELL-/bin/sh}" in
   8   *csh*) style=csh;;
   9   *) style=sh;;
  10 esac
  11 force=nil chosen= commands=
  12 while [ $# -gt 0 ]; do
  13   case "$1" in
  14     -h | --help) echo "$usage"; exit 0 ;;
  15     -c | --cshell | --tcsh) style=csh chosen=t ;;
  16     -b | --bourne | --bash | --zsh) style=sh chosen=t ;;
  17     -f | --force) force=t ;;
  18     --) shift; break ;;
  19     -*) echo >&2 "$usage"; exit 1 ;;
  20     *) break ;;
  21   esac
  22   shift
  23 done
  24 [ $# -gt 0 ] && style=commands
  25 case $chosen,$style in
  26   t,commands)
  27     echo >&2 "$0: output style and commands? you're odd"
  28     exit 1
  29     ;;
  30 esac
  31
  32 ## Some useful variables.
  33 hostname=${HOST-$(hostname)}
  34 user=${USER-${LOGNAME-$(id -un)}}
  35 dir=$TMPDIR/.ssh-agent.$hostname.$user
  36 socket=$dir/sock; pid=$dir/pid
  37 export SSH_AUTH_SOCK
  38
  39 ### Should I start a new agent?
  40 case "$force,$SSH_AUTH_SOCK" in
  41   t,* | nil,)
  42     foundp=nil
  43     ;;
  44   *)
  45     foundp=t
  46     set +e; ssh-add -l >/dev/null 2>&1; rc=$?; set -e
  47     [ $rc -ge 2 ] && foundp=nil
  48     ;;
  49 esac
  50
  51 ### If so, do that
  52 case $foundp in
  53   nil)
  54     mkdir -p -m700 "$dir"
  55     SSH_AUTH_SOCK=$socket
  56     set +e; ssh-add -l >/dev/null 2>&1; rc=$?; set -e
  57     if [ $rc -ge 2 ]; then
  58       if [ -f "$pid" ]; then
  59         kill $(cat "$pid") >/dev/null 2>&1 || :
  60       fi
  61       rm -f "$socket" "$pid"
  62       (cd /; exec ssh-agent -d -a "$socket" >/dev/null 2>&1)&
  63       echo $! >"$pid"
  64       SSH_AUTH_SOCK=$socket
  65     fi
  66     ;;
  67 esac
  68
  69 ### Run a program, or export the details
  70 case $style in
  71   sh) echo "SSH_AUTH_SOCK='$SSH_AUTH_SOCK'; export SSH_AUTH_SOCK" ;;
  72   csh) echo "setenv SSH_AUTH_SOCK '$SSH_AUTH_SOCK'" ;;
  73   commands) exec "$@" ;;
  74 esac