setpgrp.2

来自「<B>Digital的Unix操作系统VAX 4.2源码</B>」· 2 代码 · 共 61 行

.\" SCCSID: @(#)setpgrp.2	2.3	8/10/87
.TH setpgrp 2
.SH Name
setpgrp \- set process group
.SH Syntax
.ft B
setpgrp(pid, pgrp)
.br
int pid, pgrp;
.ft R
.SH Description
.NXR "setpgrp system call"
.NXA "setpgrp system call" "getpgrp system call"
.NXR "process group" "setting"
The
.PN setpgrp
system call
sets the process group of the specified process
.I pid
to the specified
.IR pgrp .
If
.I pid
is zero, the call applies to the current process.
.PP
If the invoker is not the superuser, the affected process
must either have the same effective user-id as the invoker or be 
a descendant of the invoking process.
.SH Return Values
The
.PN setpgrp
system call
returns zero (0) when the operation is successful.  If
the request fails, \-1 is returned, and the global
variable
.I errno
indicates the reason.
.SH Environment
SYSTEM_FIVE
.PP
When your program is compiled using the System V environment,
.PN setpgrp
is called without arguments and
the new process group id is returned if successful.
.SH Diagnostics
The
.PN setpgrp
system call
fails and the process group is not altered, if
one of the following occur:
.TP 15
[EPERM]
The effective user ID of the requested process is different
from that of the caller and the process is not a descendent
of the calling process.
.TP 15
[ESRCH]
The requested process does not exist.
.SH See Also
getpgrp(2)