diff options
Diffstat (limited to 'doc/DetachPids.3')
| -rw-r--r-- | doc/DetachPids.3 | 33 |
1 files changed, 23 insertions, 10 deletions
diff --git a/doc/DetachPids.3 b/doc/DetachPids.3 index 23b16c5..39a51d3 100644 --- a/doc/DetachPids.3 +++ b/doc/DetachPids.3 @@ -5,13 +5,11 @@ '\" See the file "license.terms" for information on usage and redistribution '\" of this file, and for a DISCLAIMER OF ALL WARRANTIES. '\" -'\" RCS: @(#) $Id: DetachPids.3,v 1.2 1998/09/14 18:39:48 stanton Exp $ -'\" -.so man.macros .TH Tcl_DetachPids 3 "" Tcl "Tcl Library Procedures" +.so man.macros .BS .SH NAME -Tcl_DetachPids, Tcl_ReapDetachedProcs \- manage child processes in background +Tcl_DetachPids, Tcl_ReapDetachedProcs, Tcl_WaitPid \- manage child processes in background .SH SYNOPSIS .nf \fB#include <tcl.h>\fR @@ -19,14 +17,23 @@ Tcl_DetachPids, Tcl_ReapDetachedProcs \- manage child processes in background \fBTcl_DetachPids\fR(\fInumPids, pidPtr\fR) .sp \fBTcl_ReapDetachedProcs\fR() +.sp +Tcl_Pid +\fBTcl_WaitPid\fR(\fIpid, statusPtr, options\fR) .SH ARGUMENTS -.AS int *statusPtr +.AS Tcl_Pid *statusPtr out .AP int numPids in Number of process ids contained in the array pointed to by \fIpidPtr\fR. .AP int *pidPtr in Address of array containing \fInumPids\fR process ids. +.AP Tcl_Pid pid in +The id of the process (pipe) to wait for. +.AP int *statusPtr out +The result of waiting on a process (pipe). Either 0 or ECHILD. +.AP int options in +The options controlling the wait. WNOHANG specifies not to wait when +checking the process. .BE - .SH DESCRIPTION .PP \fBTcl_DetachPids\fR and \fBTcl_ReapDetachedProcs\fR provide a @@ -42,21 +49,27 @@ overflow, even if all the children have exited. \fBTcl_DetachPids\fR may be called to ask Tcl to take responsibility for one or more processes whose process ids are contained in the \fIpidPtr\fR array passed as argument. The caller presumably -has started these processes running in background and doesn't +has started these processes running in background and does not want to have to deal with them again. .PP \fBTcl_ReapDetachedProcs\fR invokes the \fBwaitpid\fR kernel call on each of the background processes so that its state can be cleaned -up if it has exited. If the process hasn't exited yet, -\fBTcl_ReapDetachedProcs\fR doesn't wait for it to exit; it will check again +up if it has exited. If the process has not exited yet, +\fBTcl_ReapDetachedProcs\fR does not wait for it to exit; it will check again the next time it is invoked. Tcl automatically calls \fBTcl_ReapDetachedProcs\fR each time the -\fBexec\fR command is executed, so in most cases it isn't necessary +\fBexec\fR command is executed, so in most cases it is not necessary for any code outside of Tcl to invoke \fBTcl_ReapDetachedProcs\fR. However, if you call \fBTcl_DetachPids\fR in situations where the \fBexec\fR command may never get executed, you may wish to call \fBTcl_ReapDetachedProcs\fR from time to time so that background processes can be cleaned up. +.PP +\fBTcl_WaitPid\fR is a thin wrapper around the facilities provided by +the operating system to wait on the end of a spawned process and to +check a whether spawned process is still running. It is used by +\fBTcl_ReapDetachedProcs\fR and the channel system to portably access +the operating system. .SH KEYWORDS background, child, detach, process, wait |