diff options
Diffstat (limited to 'doc/close.n')
| -rw-r--r-- | doc/close.n | 28 |
1 files changed, 21 insertions, 7 deletions
diff --git a/doc/close.n b/doc/close.n index c4b1612..60a8b97 100644 --- a/doc/close.n +++ b/doc/close.n @@ -5,7 +5,7 @@ '\" See the file "license.terms" for information on usage and redistribution '\" of this file, and for a DISCLAIMER OF ALL WARRANTIES. '\" -'\" RCS: @(#) $Id: close.n,v 1.15 2008/12/18 01:14:16 ferrieux Exp $ +'\" RCS: @(#) $Id: close.n,v 1.16 2009/04/15 12:31:24 dkf Exp $ '\" .so man.macros .TH close n 7.5 Tcl "Tcl Built-In Commands" @@ -16,7 +16,6 @@ close \- Close an open channel .SH SYNOPSIS \fBclose \fIchannelId\fR ?r(ead)|w(rite)? .BE - .SH DESCRIPTION .PP Closes or half-closes the channel given by \fIchannelId\fR. @@ -58,14 +57,25 @@ an error occurs while flushing output. If a command in a command pipeline created with \fBopen\fR returns an error, \fBclose\fR generates an error (similar to the \fBexec\fR command.) .PP -The two-argument form is a "half-close": given a bidirectional channel like a socket or command pipeline and a (possibly abbreviated) direction, it closes only the substream going in that direction. This means a shutdown() on a socket, and a close() of one end of a pipe for a command pipeline. Then, the Tcl-level channel data structure is either kept or freed depending on whether the other direction is still open. +.VS 8.6 +The two-argument form is a "half-close": given a bidirectional channel like a +socket or command pipeline and a (possibly abbreviated) direction, it closes +only the substream going in that direction. This means a shutdown() on a +socket, and a close() of one end of a pipe for a command pipeline. Then, the +Tcl-level channel data structure is either kept or freed depending on whether +the other direction is still open. .PP -A single-argument close on an already half-closed bi-channel is defined to just "finish the job. A half-close on an already closed half, or on a wrong-sided unidirectional channel, raises an error. +A single-argument close on an already half-closed bi-channel is defined to +just "finish the job. A half-close on an already closed half, or on a +wrong-sided unidirectional channel, raises an error. .PP -In the case of a command pipeline, the child-reaping duty falls upon the shoulders of the last close or half-close, which is thus allowed to report an abnormal exit error. +In the case of a command pipeline, the child-reaping duty falls upon the +shoulders of the last close or half-close, which is thus allowed to report an +abnormal exit error. .PP -Currently only sockets and command pipelines support half-close. A future extension will allow reflected and stacked channels to do so. - +Currently only sockets and command pipelines support half-close. A future +extension will allow reflected and stacked channels to do so. +.VE 8.6 .SH EXAMPLE .PP This illustrates how you can use Tcl to ensure that files get closed @@ -87,3 +97,7 @@ proc withOpenFile {filename channelVar script} { file(n), open(n), socket(n), eof(n), Tcl_StandardChannels(3) .SH KEYWORDS blocking, channel, close, nonblocking, half-close +'\" Local Variables: +'\" mode: nroff +'\" fill-column: 78 +'\" End: |