Re: Terminate and Stay Resident Software (TSR) in Linux

2006-11-22, 09:28(-08), karthikbg:
[...]
What is the equivalent of TSR in linux ?
With the help of google, I found in one link that daemons are the TSRs
of linux.
But the TSR concept is quite different from the daemon concept in
Linux.

I find that, A daemon (or service) is a background process that is
designed to run autonomously,with little or not user intervention.

Further, TSR is rather than simply saying "terminate me" to DOS, it
says: "I'm xxx bytes
long. Now terminate me but DON'T OVERWRITE ME." Which is to
say: Terminate me, but let me Stay Resident.
TSR programs will be eliminated by the presence of full
multitasking operating systems.
TSR programs will be here for the duration as
necessary and viable add-ons to otherwise incomplete solutions.

So, how does TSR fit into linux as Linux is a multitasking operating
system with good solutions ?

Kindly share your views / info regarding the TSR in linux .
[...]

Your program would just wait for input. The process running your
program would then not be scheduled until some input comes.

For instance, if your program awakens itself when there's data
coming from a pipe, it would simply do:

read(pipe_fd, buf, sizeof(buf));

the "read" would block (that is that particular process wouldn't
do anything) until someone writes to the other end of the pipe.

If to be awaken by a signal, use wait(2).

If waiting from incoming connections, use listen, from incoming
data from a socket use recv... and so on.

Depends what that program is meant to do and how you want to
invoke (summon) it.

A daemon is an abstract concept. It doesn't exactly map to one
type of process.

However, generally we call daemon a process that has been
detached from a terminal, and is not interacting with a human
user.

--
Stéphane
.

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