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)}} uid=${UID-$(id -u)}
  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 foundp=nil
  41 case $force in
  42   nil)
  43     case ${SSH_AUTH_SOCK+t} in
  44       t)
  45         set +e; ssh-add -l >/dev/null 2>&1; rc=$?; set -e
  46         if [ $rc -lt 2 ]; then foundp=t; fi
  47         ;;
  48     esac
  49     case $foundp in
  50       t) ;;
  51       *)
  52         for i in \
  53           "$HOME/.cache/keyring-"*"/ssh" \
  54           "/run/user/$uid/keyring/ssh" \
  55           "$socket"
  56         do
  57           SSH_AUTH_SOCK=$i
  58           set +e; ssh-add -l >/dev/null 2>&1; rc=$?; set -e
  59           if [ $rc -lt 2 ]; then foundp=t; break; fi
  60         done
  61         ;;
  62     esac
  63     ;;
  64 esac
  65
  66 ### If so, do that
  67 case $foundp in
  68   nil)
  69     mkdir -p -m700 "$dir"
  70     SSH_AUTH_SOCK=$socket
  71     p=$PATH
  72     runes=
  73     while :; do
  74       case $p in *:*) d=${p%%:*} p=${p#*:} ;; *) d=$p p= ;; esac
  75       if [ -x "${d+$d/}setsid" ]; then runes="$runes setsid"; break; fi
  76       case $p in "") break ;; esac
  77     done
  78     set +e; ssh-add -l >/dev/null 2>&1; rc=$?; set -e
  79     if [ $rc -ge 2 ]; then
  80       if [ -f "$pid" ]; then
  81         kill $(cat "$pid") >/dev/null 2>&1 || :
  82       fi
  83       rm -f "$socket" "$pid"
  84       (cd /; exec $runes ssh-agent -d -a "$socket" </dev/null >/dev/null 2>&1)&
  85       echo $! >"$pid"
  86       SSH_AUTH_SOCK=$socket
  87     fi
  88     ;;
  89 esac
  90
  91 ### Run a program, or export the details
  92 case $style in
  93   sh) echo "SSH_AUTH_SOCK='$SSH_AUTH_SOCK'; export SSH_AUTH_SOCK" ;;
  94   csh) echo "setenv SSH_AUTH_SOCK '$SSH_AUTH_SOCK'" ;;
  95   commands) exec "$@" ;;
  96 esac