NetNews Usenet Archive 1992 #20/NN_1992_20.iso/spool/comp/unix/internal/1798

Text File | 1992-09-11 | 1.7 KB | 37 lines

Newsgroups: comp.unix.internals
Path: sparky!uunet!cis.ohio-state.edu!pacific.mps.ohio-state.edu!linac!att!cbnewsc!cbfsb!att-out!pacbell.com!tandem!hood!bill
From: [e-mail] (Bill Norcott)
Subject: Re: How can a Unix process put itself in background?
Message-ID: <[e-mail]>
Sender: [e-mail]
Nntp-Posting-Host: hood.tsg.tandem.com
Reply-To: [e-mail]  (Bill Norcott)
Organization: Tandem Computers, Inc.
References: <[e-mail]> <[e-mail]> <[e-mail]>
Date: Fri, 11 Sep 1992 22:25:46 GMT
Lines: 23

In article <[e-mail]>, [e-mail] (Barry Margolin) writes:
|> In article <[e-mail]> [e-mail]  (Bill Norcott) writes:
|> >If you have a POSIX 1003.1 conforming system, a process can put
|> >itself into the background with the setpgid() system call.
|>
|> You still have to fork first, as the shell (or whatever process started the
|> program) waits for the original process to exit.

Sure, all UNIX user processes are created by fork().  So the process
that wants to put itself into the background was created by fork().
And it's parent should be using waidpid() or wait() to wait for the
death of the child.  But the original question was, how can the guy's
existing (child) process put ITSELF in the background.  This is where
setsid() and setpgid() are used.

--
---------------------------------------------------------------------|
Bill Norcott            GUARDIAN POSIX project
Tandem Computers, Inc.
10600 N. Tantau Avenue        PHONE:  [phone]
Cupertino, CA   95014        EMAIL: [e-mail]