use tmpDir for inter-instance communication - now we can change the target (reboot/shutdown) or even abort cleanly

1 files changed, 34 insertions, 11 deletions

diff --git a/shutdownasap.in b/shutdownasap.in
index a32f92d..d2d471f 100755
--- a/shutdownasap.in
+++ b/shutdownasap.in
@@ -6,28 +6,39 @@ set -e
 
 . #ETCDIR#/shutdownasap.conf
 
-[ -r "${pidFile}" ] && ps aux | grep -q "^\S\+\s\+$(cat "${pidFile}") " && exit
-
-echo $$ > "${pidFile}"
+mkdir -p "${tmpDir}"
 
 quiet=false
-reboot=false
+intentionSet=false
 while [ $# -gt 0 ]; do
   case "$1" in
+    '-a')
+      echo 'none' >"${tmpDir}/intention"
+      exit
+    ;;
     '-q')
       quiet=true
     ;;
     '-r')
-      reboot=true
+      echo 'reboot' >"${tmpDir}/intention"
+      intentionSet=true
     ;;
     *)
-      >&2 echo 'usage: shutdownasap [-q] [-r]'
+      >&2 echo 'usage: shutdownasap [-q] [-a|-r]'
       exit 1
     ;;
   esac
   shift
 done
 
+if ! ${intentionSet}; then
+  echo 'shutdown' >"${tmpDir}/intention"
+fi
+
+[ -r "${tmpDir}/pid" ] && kill -0 "$(cat "${tmpDir}/pid")" && exit
+
+echo $$ > "${tmpDir}/pid"
+
 beforeWatchHook
 
 i=1
@@ -130,8 +141,20 @@ else
   pre=''
 fi
 
-if ${reboot}; then
-  ${pre} /sbin/reboot
-else
-  ${pre} /sbin/poweroff
-fi
+case "$(head -n1 "${tmpDir}/intention")" in
+  'reboot')
+    ${pre} /sbin/reboot
+  ;;
+  'shutdown')
+    ${pre} /sbin/poweroff
+  ;;
+  'none')
+    echo 'shutdown was aborted'
+  ;;
+  *)
+    printf 'intention "%s" not implemented\n' "$(head -n1 "${tmpDir}/intention")"
+    exit 1
+  ;;
+esac
+
+rm -rf --one-file-system "${tmpDir}"