I am looking for something that suspends the boot process (before certain services are started). It would prompt the console for user input after which I could use that input and continue booting the machine.
Much like the pass phrase dialog that is presented when there are encrypted drives.
If there is nothing 'off-the-shelf' then I am proficient enough to write c/c++ that takes input from stdin and processes that. How do I go about suspending the boot process? Do I simply place my program in say /etc/rc3.d with an appropriate level in the binary name? Would the boot process simply wait until that process finishes? Any pointers would be appreciated.
I intend to use shared memory to store this user input, so the boot process must be suspended where that is available to me.
Target system is CentOS 6.