diff options
Diffstat (limited to 'doc/chan.n')
| -rw-r--r-- | doc/chan.n | 38 |
1 files changed, 19 insertions, 19 deletions
@@ -3,8 +3,8 @@ '\" '\" See the file "license.terms" for information on usage and redistribution '\" of this file, and for a DISCLAIMER OF ALL WARRANTIES. -.so man.macros .TH chan n 8.5 Tcl "Tcl Built-In Commands" +.so man.macros .BS '\" Note: do not modify the .SH NAME line immediately below! .SH NAME @@ -57,7 +57,7 @@ closed). .PP If the channel is blocking and the channel is ceasing to be writable, the command does not return until all output is flushed. If the channel is -nonblocking and there is unflushed output, the channel remains open and the +non-blocking and there is unflushed output, the channel remains open and the command returns immediately; output will be flushed in the background and the channel will be closed when all the flushing is complete. .PP @@ -107,8 +107,8 @@ the command sets each of the named options to the corresponding .PP The options described below are supported for all channels. In addition, each channel type may add options that only it supports. See -the manual entry for the command that creates each type of channels -for the options that that specific type of channel supports. For +the manual entry for the command that creates each type of channel +for the options supported by that specific type of channel. For example, see the manual entry for the \fBsocket\fR command for additional options for sockets, and the \fBopen\fR command for additional options for serial devices. @@ -118,10 +118,10 @@ serial devices. The \fB\-blocking\fR option determines whether I/O operations on the channel can cause the process to block indefinitely. The value of the option must be a proper boolean value. Channels are normally in -blocking mode; if a channel is placed into nonblocking mode it will +blocking mode; if a channel is placed into non-blocking mode it will affect the operation of the \fBchan gets\fR, \fBchan read\fR, \fBchan puts\fR, \fBchan flush\fR, and \fBchan close\fR commands; see the -documentation for those commands for details. For nonblocking mode to +documentation for those commands for details. For non-blocking mode to work correctly, the application must be using the Tcl event loop (e.g. by calling \fBTcl_DoOneEvent\fR or invoking the \fBvwait\fR command). @@ -399,7 +399,7 @@ commands. When a thread or interpreter is deleted, all channels created with this subcommand and using this thread/interpreter as their computing base are deleted as well, in all interpreters they have been shared -with or moved into, and in whatever thread they have been transfered +with or moved into, and in whatever thread they have been transferred to. While this pulls the rug out under the other thread(s) and/or interpreter(s), this cannot be avoided. Trying to use such a channel will cause the generation of a regular error about unknown channel @@ -453,7 +453,7 @@ be readable if there is unread data in an input buffer, except in the special case where the most recent attempt to read from the channel was a \fBchan gets\fR call that could not find a complete line in the input buffer. This feature allows a file to be read a line at a time -in nonblocking mode using events. A channel is also considered to be +in non-blocking mode using events. A channel is also considered to be readable if an end of file or error condition is present on the underlying file or device. It is important for \fIscript\fR to check for these conditions and handle them appropriately; for example, if @@ -468,12 +468,12 @@ Note that client sockets opened in asynchronous mode become writable when they become connected or if the connection fails. .PP Event-driven I/O works best for channels that have been placed into -nonblocking mode with the \fBchan configure\fR command. In blocking +non-blocking mode with the \fBchan configure\fR command. In blocking mode, a \fBchan puts\fR command may block if you give it more data than the underlying file or device can accept, and a \fBchan gets\fR or \fBchan read\fR command will block if you attempt to read more data than is ready; no events will be processed while the commands block. -In nonblocking mode \fBchan puts\fR, \fBchan read\fR, and \fBchan +In non-blocking mode \fBchan puts\fR, \fBchan read\fR, and \fBchan gets\fR never block. .PP The script for a file event is executed at global level (outside the @@ -493,7 +493,7 @@ is written. .PP If the channel is in blocking mode the command does not return until all the buffered output has been flushed to the channel. If the -channel is in nonblocking mode, the command may return before all +channel is in non-blocking mode, the command may return before all buffered output has been flushed; the remainder will be flushed in the background as fast as the underlying file or device is able to absorb it. @@ -516,7 +516,7 @@ If an end-of-file occurs while part way through reading a line, the partial line will be returned (or written into \fIvarName\fR). When \fIvarName\fR is not specified, the end-of-file case can be distinguished from an empty line using the \fBchan eof\fR command, and -the partial-line-but-nonblocking case can be distinguished with the +the partial-line-but-non-blocking case can be distinguished with the \fBchan blocked\fR command. .RE .TP @@ -630,16 +630,16 @@ flush\fR command. .PP When the output buffer fills up, the \fBchan puts\fR command will normally block until all the buffered data has been accepted for -output by the operating system. If \fIchannelId\fR is in nonblocking +output by the operating system. If \fIchannelId\fR is in non-blocking mode then the \fBchan puts\fR command will not block even if the operating system cannot accept the data. Instead, Tcl continues to buffer the data and writes it in the background as fast as the underlying file or device can accept it. The application must use the -Tcl event loop for nonblocking output to work; otherwise Tcl never +Tcl event loop for non-blocking output to work; otherwise Tcl never finds out that the file or device is ready for more output data. It is possible for an arbitrarily large amount of data to be buffered for -a channel in nonblocking mode, which could consume a large amount of -memory. To avoid wasting memory, nonblocking I/O should normally be +a channel in non-blocking mode, which could consume a large amount of +memory. To avoid wasting memory, non-blocking I/O should normally be used in an event-driven fashion with the \fBchan event\fR command (do not invoke \fBchan puts\fR unless you have recently been notified via a file event that the channel is ready for more output data). @@ -659,7 +659,7 @@ given to indicate that any trailing newline in the string that has been read should be trimmed. .RS .PP -If \fIchannelId\fR is in nonblocking mode, \fBchan read\fR may not +If \fIchannelId\fR is in non-blocking mode, \fBchan read\fR may not read as many characters as requested: once all available input has been read, the command will return the data that is available rather than blocking for more input. If the channel is configured to use a @@ -675,7 +675,7 @@ channel (see \fBchan configure\fR above for a discussion on the ways in which \fBchan configure\fR will alter input). .PP When reading from a serial port, most applications should configure -the serial port channel to be nonblocking, like this: +the serial port channel to be non-blocking, like this: .PP .CS \fBchan configure \fIchannelId \fB\-blocking \fI0\fR. @@ -728,7 +728,7 @@ position after the end of file. The \fIorigin\fR argument defaults to \fBstart\fR. .PP \fBChan seek\fR flushes all buffered output for the channel before the -command returns, even if the channel is in nonblocking mode. It also +command returns, even if the channel is in non-blocking mode. It also discards any buffered and unread input. This command returns an empty string. An error occurs if this command is applied to channels whose underlying file or device does not support seeking. |