Solaris: reboot vs init to get to single-user mode

Your question basically includes the answer.... A script that'll iterate through a subdir of each users home, looking for executable scripts. Then it sudo -u user /export/home/user/scripts/scriptname.sh start. You'll have no control over what the scripts do, so you`ll need to trust your users.

Insist that they write their scripts to accept stop start restart as $1 param and that they shouldn't use any environment variables that have been set up in their .profile, .cshrc or .bashrc files. The script effectively needs to be standalone.

#!/usr/bin/bash

run_cmd {
cd /export/home
for HOMEDIR in *; do
  for SCRIPT in /export/home/$HOMEDIR/scripts/*;  do
     if [ -x $SCRIPT ]; then
       echo "$ACTION user $HOMEDIR's script $SCRIPT"
       sudo -u $HOMEDIR $SCRIPT $ACTION &
     fi
  done
done

}

case $1 in
    start) ACTION=start;
           run_cmd;;
    stop) ACTION=stop;
           run_cmd;;
    restart) ACTION=stop;
             run_cmd;
             sleep 60;
             ACTION=start;
             run_cmd;;
    *) echo "$1 not recognized as valid cmd";;
esac

exit 0

You'll need to tweak this for your environment, location of bash/homedirs etc.

The initrd contains a gzipped cpio dump that's put onto a ramdisk during init. Setuproot loads any necessary modules (contained in the initrd), generally for things like LVM, populates /dev (the initrd contains a limited /dev). Switchroot pivots off the cpio archive to the real root filesystem.

nash is extremely limited. Every binary must be static, scripting is virtually impossible, etc. This may be helpful (build scripts are in his SVN repo).