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 ## Check that this stands a chance of working.
  33 if ! type >/dev/null 2>&1 ssh-agent || ! type >/dev/null >&1 ssh-add; then
  34   echo >&2 "$0: ssh not installed; chickening out"
  35   exit 1
  36 fi
  37
  38 ## Some useful variables.
  39 hostname=${HOST-$(hostname)}
  40 user=${USER-${LOGNAME-$(id -un)}} uid=${UID-$(id -u)}
  41 dir=$TMPDIR/.ssh-agent.$hostname.$user
  42 socket=$dir/sock; pid=$dir/pid
  43 export SSH_AUTH_SOCK
  44
  45 ## Should I start a new agent?
  46 foundp=nil
  47 case $force in
  48   nil)
  49     case ${SSH_AUTH_SOCK+t} in
  50       t)
  51         set +e; ssh-add -l >/dev/null 2>&1; rc=$?; set -e
  52         if [ $rc -lt 2 ]; then foundp=t; fi
  53         ;;
  54     esac
  55     case $foundp in
  56       t) ;;
  57       *)
  58         for i in \
  59           "$HOME/.cache/keyring-"*"/ssh" \
  60           "/run/user/$uid/keyring/ssh" \
  61           "$socket"
  62         do
  63           SSH_AUTH_SOCK=$i
  64           set +e; ssh-add -l >/dev/null 2>&1; rc=$?; set -e
  65           if [ $rc -lt 2 ]; then foundp=t; break; fi
  66         done
  67         ;;
  68     esac
  69     ;;
  70 esac
  71
  72 ### If so, do that
  73 case $foundp in
  74   nil)
  75     mkdir -p -m700 "$dir"
  76     SSH_AUTH_SOCK=$socket
  77     p=$PATH
  78     runes=
  79     while :; do
  80       case $p in *:*) d=${p%%:*} p=${p#*:} ;; *) d=$p p= ;; esac
  81       if [ -x "${d+$d/}setsid" ]; then runes="$runes setsid"; break; fi
  82       case $p in "") break ;; esac
  83     done
  84     set +e; ssh-add -l >/dev/null 2>&1; rc=$?; set -e
  85     if [ $rc -ge 2 ]; then
  86       if [ -f "$pid" ]; then
  87         kill $(cat "$pid") >/dev/null 2>&1 || :
  88       fi
  89       rm -f "$socket" "$pid"
  90       (cd /; exec $runes ssh-agent -d -a "$socket" </dev/null >/dev/null 2>&1)&
  91       echo $! >"$pid"
  92       SSH_AUTH_SOCK=$socket
  93     fi
  94     ;;
  95 esac
  96
  97 ### Run a program, or export the details
  98 case $style in
  99   sh) echo "SSH_AUTH_SOCK='$SSH_AUTH_SOCK'; export SSH_AUTH_SOCK" ;;
 100   csh) echo "setenv SSH_AUTH_SOCK '$SSH_AUTH_SOCK'" ;;
 101   commands) exec "$@" ;;
 102 esac