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Diffstat (limited to 'doc')
| -rw-r--r-- | doc/chan.n | 13 |
1 files changed, 12 insertions, 1 deletions
@@ -4,7 +4,7 @@ '\" See the file "license.terms" for information on usage and redistribution '\" of this file, and for a DISCLAIMER OF ALL WARRANTIES. '\" -'\" RCS: @(#) $Id: chan.n,v 1.17 2007/12/13 15:22:32 dgp Exp $ +'\" RCS: @(#) $Id: chan.n,v 1.18 2008/07/21 21:02:15 ferrieux Exp $ .so man.macros .TH chan n 8.5 Tcl "Tcl Built-In Commands" .BS @@ -697,6 +697,17 @@ Sets the byte length of the underlying data stream for the channel named \fIchannelId\fR to be \fIlength\fR (or to the current byte offset within the underlying data stream if \fIlength\fR is omitted). The channel is flushed before truncation. +.TP +\fBchan pipe\fR +. +Creates a standalone pipe whose read- and write-side channels are +returned as a 2-element list, the first element being the read side and +the second the write side. Can be useful e.g. to redirect +separately stderr and stdout from a subprocess. To do this, spawn with "2>@" or +">@" redirection operators onto the write side of a pipe, and then +immediately close it in the parent. This is necessary to get an EOF on +the read side once the child has exited or otherwise closed its output. +. .SH EXAMPLE This opens a file using a known encoding (CP1252, a very common encoding on Windows), searches for a string, rewrites that part, and truncates the |