wait.1

来自「<B>Digital的Unix操作系统VAX 4.2源码</B>」· 1 代码 · 共 45 行

.\" SCCSID: @(#)wait.1	8.1	9/11/90
.TH wait 1 
.SH Name
wait \- wait for process completion
.SH Syntax
.B wait
[\fIpid\fR]
.SH Description
.NXR "wait command (general)"
.NXA "sh command interpreter" "wait command (general)"
.NXR "diagnostics" "handling"
The
.PN wait
command
waits until all processes started with an ampersand
(\fB&\fR)
have completed
and reports on abnormal terminations.
.PP
If a numeric \fIpid\fR is given and is the process ID of a background
process, then
.PN wait
waits
until that process is completed.  
If \fIpid\fR
is not a background process, 
.PN wait
waits until all background processes have completed.
.PP
Because the
.MS wait 2
system call must be executed in the parent process,
the Shell itself executes
.PN wait
without creating a new process.
.SH Restrictions
Because not all the processes of a 3- or more-stage
pipeline are children of the Shell, the
.PN wait 
command does not work on them.
.PP
The [\fIpid\fR] is available only with sh5.
.SH See Also
sh(1), sh5(1), wait(2)