diff options
Diffstat (limited to 'doc')
| -rw-r--r-- | doc/chan.n | 42 |
1 files changed, 40 insertions, 2 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 1.22 2008/10/15 10:43:37 dkf Exp $ +'\" RCS: @(#) $Id: chan.n,v 1.23 2009/01/30 11:34:36 dkf Exp $ .so man.macros .TH chan n 8.5 Tcl "Tcl Built-In Commands" .BS @@ -733,7 +733,8 @@ 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. . -.SH EXAMPLE +.SH EXAMPLES +.PP 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 file after a further two lines. @@ -766,6 +767,43 @@ while {[\fBchan gets\fR $f line] >= 0} { } \fBchan close\fR $f .CE +.PP +A network server that does echoing of its input line-by-line without +preventing servicing of other connections at the same time. +.PP +.CS +# This is a very simple logger... +proc log {message} { + \fBchan puts\fR stdout $message +} + +# This is called whenever a new client connects to the server +proc connect {chan host port} { + set clientName [format <%s:%d> $host $port] + log "connection from $clientName" + \fBchan configure\fR $chan -blocking 0 -buffering line + \fBchan event\fR $chan readable [list echoLine $chan $clientName] +} + +# This is called whenever either at least one byte of input +# data is available, or the channel was closed by the client. +proc echoLine {chan clientName} { + \fBchan gets\fR $chan line + if {[\fBchan eof\fR $chan]} { + log "finishing connection from $clientName" + \fBchan close\fR $chan + } elseif {![\fBchan blocked\fR $chan]} { + # Didn't block waiting for end-of-line + log "$clientName - $line" + \fBchan puts\fR $chan $line + } +} + +# Create the server socket and enter the event-loop to wait +# for incoming connections... +socket -server connect 12345 +vwait forever +.CE .SH "SEE ALSO" close(n), eof(n), fblocked(n), fconfigure(n), fcopy(n), file(n), fileevent(n), flush(n), gets(n), open(n), puts(n), read(n), seek(n), |