diff options
Diffstat (limited to 'doc/close.n')
| -rw-r--r-- | doc/close.n | 21 |
1 files changed, 19 insertions, 2 deletions
diff --git a/doc/close.n b/doc/close.n index 501d282..28fe971 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 1.4 2001/09/14 19:20:40 andreas_kupries Exp $ +'\" RCS: @(#) $Id: close.n,v 1.4.8.1 2004/10/27 09:35:38 dkf Exp $ '\" .so man.macros .TH close n 7.5 Tcl "Tcl Built-In Commands" @@ -59,7 +59,24 @@ that all output is correctly flushed before the process exits. .VE .PP The command returns an empty string, and may generate an error if -an error occurs while flushing output. +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.) +.SH EXAMPLE +This illustrates how you can use Tcl to ensure that files get closed +even when errors happen by combining \fBcatch\fR, \fBclose\fR and +\fBreturn\fR: +.CS +proc withOpenFile {filename channelVar script} { + upvar 1 $channelVar chan + set chan [open $filename] + catch { + uplevel 1 $script + } result options + \fBclose\fR $chan + return -options $options $result +} +.CE .SH "SEE ALSO" file(n), open(n), socket(n), eof(n), Tcl_StandardChannels(3) |