Yes, rc.M is last before spawning tty's.
Let analyse your task:
You want some startup sciprt to continuously print content of interactive log file (/data/recv.cfg) to some tty(let it be tty2)?
I see next solution:
1. Let prepare command to print log. We shall put into /root/logger
exec /usr/bin/tail -f /data/recv.cfg
You can make it more complex. Don't forget to set x attribute.
2. We know it is possible after actual connecting tty2 to console(made by agetty).
So our task is to force to call our logger during spawning on tty. Well, after brief reading of "man agetty" and "man inittab"(for testing purposes) solution is oblivious for me.
Go edit /etc/inittab (do backup!!!)
find line "c2:12345:respawn:/sbin/agetty 38400 tty2 linux"
and replace it by line "c2:12345:respawn:/sbin/agetty -n -l /root/logger 38400 tty2 linux"
"-n" means do not prompt username
"-l /root/logger" means run given executable instead standard /sbin/login.
To test it:
1. Completely logoff on tty2(if logged on), switch back to non-tty2.
2. Ask init to re-read /etc/inittab using command: @ telinit q
3. Terminate corresponding tty console by command: @ kill -s $(ps a |grep agetty |grep tty2 |cut -f 1 -d" ") OR use top/htop/... to kill tty2.
init will rerun corresponding process immediately but with new parameters(actually, you can change not only parameters but whole command, it identifies process to rerun by its id, "c2" in out case).
Switch to tty2(alt+f2) now you can see content of your log file in that tty.
As a side effect you cannot login in tty2 any more. Probably there are other side effects, this will be your homework.