diff options
Diffstat (limited to 'doc/fconfigure.n')
| -rw-r--r-- | doc/fconfigure.n | 316 |
1 files changed, 99 insertions, 217 deletions
diff --git a/doc/fconfigure.n b/doc/fconfigure.n index da52671..ca23314 100644 --- a/doc/fconfigure.n +++ b/doc/fconfigure.n @@ -4,10 +4,8 @@ '\" See the file "license.terms" for information on usage and redistribution '\" of this file, and for a DISCLAIMER OF ALL WARRANTIES. '\" -'\" RCS: @(#) $Id: fconfigure.n,v 1.7 2002/07/01 18:24:39 jenglish Exp $ -'\" -.so man.macros .TH fconfigure n 8.3 Tcl "Tcl Built-In Commands" +.so man.macros .BS '\" Note: do not modify the .SH NAME line immediately below! .SH NAME @@ -41,7 +39,8 @@ 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 example, see the manual -entry for the \fBsocket\fR command for its additional options. +entry for the \fBsocket\fR command for additional options for sockets, and +the \fBopen\fR command for additional options for serial devices. .TP \fB\-blocking\fR \fIboolean\fR The \fB\-blocking\fR option determines whether I/O operations on the @@ -49,7 +48,8 @@ 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 affect the operation of the \fBgets\fR, -\fBread\fR, \fBputs\fR, \fBflush\fR, and \fBclose\fR commands; +\fBread\fR, \fBputs\fR, \fBflush\fR, and \fBclose\fR commands by +allowing them to operate asynchronously; see the documentation for those commands for details. For nonblocking mode to work correctly, the application must be using the Tcl event loop (e.g. by calling \fBTcl_DoOneEvent\fR or @@ -72,8 +72,8 @@ initially set to \fBline\fR, and \fBstderr\fR is set to \fBnone\fR. . \fINewvalue\fR must be an integer; its value is used to set the size of buffers, in bytes, subsequently allocated for this channel to store input -or output. \fINewvalue\fR must be between ten and one million, allowing -buffers of ten to one million bytes in size. +or output. \fINewvalue\fR must be between one and one million, allowing +buffers of one to one million bytes in size. .TP \fB\-encoding\fR \fIname\fR . @@ -91,11 +91,14 @@ If a file contains pure binary data (for instance, a JPEG image), the encoding for the channel should be configured to be \fBbinary\fR. Tcl will then assign no interpretation to the data in the file and simply read or write raw bytes. The Tcl \fBbinary\fR command can be used to manipulate this -byte-oriented data. +byte-oriented data. It is usually better to set the +\fB\-translation\fR option to \fBbinary\fR when you want to transfer +binary data, as this turns off the other automatic interpretations of +the bytes in the stream as well. .PP The default encoding for newly opened channels is the same platform- and locale-dependent system encoding used for interfacing with the operating -system. +system, as returned by \fBencoding system\fR. .RE .TP \fB\-eofchar\fR \fIchar\fR @@ -116,6 +119,9 @@ channel, a two-element list will always be returned. The default value for \fB\-eofchar\fR is the empty string in all cases except for files under Windows. In that case the \fB\-eofchar\fR is Control-z (\ex1a) for reading and the empty string for writing. +The acceptable range for \fB\-eofchar\fR values is \ex01 - \ex7f; +attempting to set \fB\-eofchar\fR to a value outside of this range will +generate an error. .TP \fB\-translation\fR \fImode\fR .TP @@ -126,11 +132,11 @@ newline character (\en). However, in actual files and devices the end of a line may be represented differently on different platforms, or even for different devices on the same platform. For example, under UNIX newlines are used in files, whereas carriage-return-linefeed sequences are -normally used in network connections. On input (i.e., with \fBgets\fP -and \fBread\fP) the Tcl I/O system automatically translates the external +normally used in network connections. On input (i.e., with \fBgets\fR +and \fBread\fR) the Tcl I/O system automatically translates the external end-of-line representation into newline characters. Upon output (i.e., -with \fBputs\fP), the I/O system translates newlines to the external -end-of-line representation. The default translation mode, \fBauto\fP, +with \fBputs\fR), the I/O system translates newlines to the external +end-of-line representation. The default translation mode, \fBauto\fR, handles all the common cases automatically, but the \fB\-translation\fR option provides explicit control over the end of line translations. .RS @@ -148,39 +154,45 @@ currently supported: \fBauto\fR . As the input translation mode, \fBauto\fR treats any of newline -(\fBlf\fP), carriage return (\fBcr\fP), or carriage return followed by a -newline (\fBcrlf\fP) as the end of line representation. The end of line +(\fBlf\fR), carriage return (\fBcr\fR), or carriage return followed by a +newline (\fBcrlf\fR) as the end of line representation. The end of line representation can even change from line-to-line, and all cases are translated to a newline. As the output translation mode, \fBauto\fR chooses a platform specific representation; for sockets on all platforms -Tcl chooses \fBcrlf\fR, for all Unix flavors, it chooses \fBlf\fR, for the -Macintosh platform it chooses \fBcr\fR and for the various flavors of -Windows it chooses \fBcrlf\fR. The default setting for -\fB\-translation\fR is \fBauto\fR for both input and output. +Tcl chooses \fBcrlf\fR, for all Unix flavors, it chooses \fBlf\fR, and +for the various flavors of Windows it chooses \fBcrlf\fR. The default +setting for \fB\-translation\fR is \fBauto\fR for both input and output. .TP \fBbinary\fR . No end-of-line translations are performed. This is nearly identical to -\fBlf\fP mode, except that in addition \fBbinary\fP mode also sets the +\fBlf\fR mode, except that in addition \fBbinary\fR mode also sets the end-of-file character to the empty string (which disables it) and sets the encoding to \fBbinary\fR (which disables encoding filtering). See the description of \fB\-eofchar\fR and \fB\-encoding\fR for more information. +.RS +.PP +Internally, i.e. when it comes to the actual behaviour of the +translator this value \fBis\fR identical to \fBlf\fR and is therefore +reported as such when queried. Even if \fBbinary\fR was used to set +the translation. +.RE .TP \fBcr\fR . The end of a line in the underlying file or device is represented by a single carriage return character. As the input translation mode, -\fBcr\fP mode converts carriage returns to newline characters. As the -output translation mode, \fBcr\fP mode translates newline characters to -carriage returns. This mode is typically used on Macintosh platforms. +\fBcr\fR mode converts carriage returns to newline characters. As the +output translation mode, \fBcr\fR mode translates newline characters to +carriage returns. .TP \fBcrlf\fR . The end of a line in the underlying file or device is represented by a carriage return character followed by a linefeed character. As the input -translation mode, \fBcrlf\fP mode converts carriage-return-linefeed +translation mode, \fBcrlf\fR mode converts carriage-return-linefeed sequences to newline characters. As the output translation mode, -\fBcrlf\fP mode translates newline characters to carriage-return-linefeed +\fBcrlf\fR mode translates newline characters to carriage-return-linefeed sequences. This mode is typically used on Windows platforms and for network connections. .TP @@ -192,7 +204,6 @@ during either input or output. This mode is typically used on UNIX platforms. .RE .PP - .SH "STANDARD CHANNELS" .PP The Tcl standard channels (\fBstdin\fR, \fBstdout\fR, and \fBstderr\fR) @@ -202,206 +213,77 @@ will also support any special option according to their current type. If, for example, a Tcl application is started by the \fBinet\fR super-server common on Unix system its Tcl standard channels will be sockets and thus support the socket options. - -.VS 8.4 -.SH "SERIAL PORT CONFIGURATION OPTIONS" +.SH EXAMPLES .PP -If \fIchannelId\fR refers to a serial port, then the following -additional configuration options are available on Windows and -Unix systems with a POSIX serial interface: - -.TP -\fB\-mode\fR \fIbaud\fB,\fIparity\fB,\fIdata\fB,\fIstop\fR -. -This option is a set of 4 comma-separated values: the baud rate, parity, -number of data bits, and number of stop bits for this serial port. The -\fIbaud\fR rate is a simple integer that specifies the connection speed. -\fIParity\fR is one of the following letters: \fBn\fR, \fBo\fR, \fBe\fR, -\fBm\fR, \fBs\fR; respectively signifying the parity options of ``none'', -``odd'', ``even'', ``mark'', or ``space''. \fIData\fR is the number of -data bits and should be an integer from 5 to 8, while \fIstop\fR is the -number of stop bits and should be the integer 1 or 2. - -.TP -\fB\-handshake\fR \fItype\fR -. -(Windows and Unix). This option is used to setup automatic handshake -control. Note that not all handshake types maybe supported by your operating -system. The \fItype\fR parameter is case-independent. - -If \fItype\fR is \fBnone\fR then any handshake is switched off. -\fBrtscts\fR activates hardware handshake. Hardware handshake signals -are described below. -For software handshake \fBxonxoff\fR the handshake characters can be redefined -with \fB-xchar\fR. -An additional hardware handshake \fBdtrdsr\fR is available only under Windows. -There is no default handshake configuration, the initial value depends -on your operating system settings. -The \fB-handshake\fR option cannot be queried. - -.TP -\fB\-queue\fR -. -(Windows and Unix). The \fB-queue\fR option can only be queried. -It returns a list of two integers representing the current number -of bytes in the input and output queue respectively. - -.TP -\fB\-timeout\fR \fImsec\fR -. -(Windows and Unix). This option is used to set the timeout for blocking -read operations. It specifies the maximum interval between the -reception of two bytes in milliseconds. -For Unix systems the granularity is 100 milliseconds. -The \fB-timeout\fR option does not affect write operations or -nonblocking reads. -This option cannot be queried. - -.TP -\fB\-ttycontrol\fR \fI{signal boolean signal boolean ...}\fR -. -(Windows and Unix). This option is used to setup the handshake -output lines (see below) permanently or to send a BREAK over the serial line. -The \fIsignal\fR names are case-independent. -\fB{RTS 1 DTR 0}\fR sets the RTS output to high and the DTR output to low. -The BREAK condition (see below) is enabled and disabled with \fB{BREAK 1}\fR and -\fB{BREAK 0}\fR respectively. -It's not a good idea to change the \fBRTS\fR (or \fBDTR\fR) signal -with active hardware handshake \fBrtscts\fR (or \fBdtrdsr\fR). -The result is unpredictable. -The \fB-ttycontrol\fR option cannot be queried. - -.TP -\fB\-ttystatus\fR -. -(Windows and Unix). The \fB-ttystatus\fR option can only be -queried. It returns the current modem status and handshake input signals -(see below). -The result is a list of signal,value pairs with a fixed order, -e.g. \fB{CTS 1 DSR 0 RING 1 DCD 0}\fR. -The \fIsignal\fR names are returned upper case. +Instruct Tcl to always send output to \fBstdout\fR immediately, +whether or not it is to a terminal: +.PP +.CS +\fBfconfigure\fR stdout -buffering none +.CE +.PP +Open a socket and read lines from it without ever blocking the +processing of other events: +.PP +.CS +set s [socket some.where.com 12345] +\fBfconfigure\fR $s -blocking 0 +fileevent $s readable "readMe $s" +proc readMe chan { + if {[gets $chan line] < 0} { + if {[eof $chan]} { + close $chan + return + } + # Could not read a complete line this time; Tcl's + # internal buffering will hold the partial line for us + # until some more data is available over the socket. + } else { + puts stdout $line + } +} +.CE +.PP +Read a PPM-format image from a file: +.PP +.CS +# Open the file and put it into Unix ASCII mode +set f [open teapot.ppm] +\fBfconfigure\fR $f \-encoding ascii \-translation lf -.TP -\fB\-xchar\fR \fI{xonChar xoffChar}\fR -. -(Windows and Unix). This option is used to query or change the software -handshake characters. Normally the operating system default should be -DC1 (0x11) and DC3 (0x13) representing the ASCII standard -XON and XOFF characters. +# Get the header +if {[gets $f] ne "P6"} { + error "not a raw\-bits PPM" +} -.TP -\fB\-pollinterval\fR \fImsec\fR -. -(Windows only). This option is used to set the maximum time between -polling for fileevents. -This affects the time interval between checking for events throughout the Tcl -interpreter (the smallest value always wins). Use this option only if -you want to poll the serial port more or less often than 10 msec -(the default). +# Read lines until we have got non-comment lines +# that supply us with three decimal values. +set words {} +while {[llength $words] < 3} { + gets $f line + if {[string match "#*" $line]} continue + lappend words {*}[join [scan $line %d%d%d]] +} -.TP -\fB\-sysbuffer\fR \fIinSize\fR -.TP -\fB\-sysbuffer\fR \fI{inSize outSize}\fR -. -(Windows only). This option is used to change the size of Windows -system buffers for a serial channel. Especially at higher communication -rates the default input buffer size of 4096 bytes can overrun -for latent systems. The first form specifies the input buffer size, -in the second form both input and output buffers are defined. - -.TP -\fB\-lasterror\fR -. -(Windows only). This option is query only. -In case of a serial communication error, \fBread\fR or \fBputs\fR -returns a general Tcl file I/O error. -\fBfconfigure -lasterror\fR can be called to get a list of error details. -See below for an explanation of the various error codes. - -.SH "SERIAL PORT SIGNALS" -.PP -RS-232 is the most commonly used standard electrical interface for serial -communications. A negative voltage (-3V..-12V) define a mark (on=1) bit and -a positive voltage (+3..+12V) define a space (off=0) bit (RS-232C). The -following signals are specified for incoming and outgoing data, status -lines and handshaking. Here we are using the terms \fIworkstation\fR for -your computer and \fImodem\fR for the external device, because some signal -names (DCD, RI) come from modems. Of course your external device may use -these signal lines for other purposes. -.RS -.IP \fBTXD(output)\fR -\fBTransmitted Data:\fR Outgoing serial data. -.IP \fBRXD(input)\fR -\fBReceived Data:\fRIncoming serial data. -.IP \fBRTS(output)\fR -\fBRequest To Send:\fR This hardware handshake line informs the modem that -your workstation is ready to receive data. Your workstation may -automatically reset this signal to indicate that the input buffer is full. -.IP \fBCTS(input)\fR -\fBClear To Send:\fR The complement to RTS. Indicates that the modem is -ready to receive data. -.IP \fBDTR(output)\fR -\fBData Terminal Ready:\fR This signal tells the modem that the workstation -is ready to establish a link. DTR is often enabled automatically whenever a -serial port is opened. -.IP \fBDSR(input)\fR -\fBData Set Ready:\fR The complement to DTR. Tells the workstation that the -modem is ready to establish a link. -.IP \fBDCD(input)\fR -\fBData Carrier Detect:\fR This line becomes active when a modem detects -a "Carrier" signal. -.IP \fBRI(input)\fR -\fBRing Indicator:\fR Goes active when the modem detects an incoming call. -.IP \fBBREAK\fR -A BREAK condition is not a hardware signal line, but a logical zero on the -TXD or RXD lines for a long period of time, usually 250 to 500 -milliseconds. Normally a receive or transmit data signal stays at the mark -(on=1) voltage until the next character is transferred. A BREAK is sometimes -used to reset the communications line or change the operating mode of -communications hardware. -.RE +# Those words supply the size of the image and its +# overall depth per channel. Assign to variables. +lassign $words xSize ySize depth -.SH "ERROR CODES (Windows only)" -.PP -A lot of different errors may occur during serial read operations or during -event polling in background. The external device may have been switched -off, the data lines may be noisy, system buffers may overrun or your mode -settings may be wrong. That's why a reliable software should always -\fBcatch\fR serial read operations. In cases of an error Tcl returns a -general file I/O error. Then \fBfconfigure -lasterror\fR may help to -locate the problem. The following error codes may be returned. -.RS -.IP \fBRXOVER:\fR -Windows input buffer overrun. The data comes faster than your scripts reads -it or your system is overloaded. Use \fBfconfigure -sysbuffer\fR to avoid a -temporary bottleneck and/or make your script faster. -.IP \fBTXFULL\fR -Windows output buffer overrun. Complement to RXOVER. This error should -practically not happen, because Tcl cares about the output buffer status. -.IP \fBOVERRUN\fR -UART buffer overrun (hardware) with data lost. -The data comes faster than the system driver receives it. -Check your advanced serial port settings to enable the FIFO (16550) buffer -and/or setup a lower(1) interrupt threshold value. -.IP \fBRXPARITY\fR -A parity error has been detected by your UART. -Wrong parity settings with \fBfconfigure -mode\fR or a noisy data line (RXD) -may cause this error. -.IP \fBFRAME\fR -A stop-bit error has been detected by your UART. -Wrong mode settings with \fBfconfigure -mode\fR or a noisy data line (RXD) -may cause this error. -.IP \fBBREAK\fR -A BREAK condition has been detected by your UART (see above). -.RE -.VE +# Now switch to binary mode to pull in the data, +# one byte per channel (red,green,blue) per pixel. +\fBfconfigure\fR $f \-translation binary +set numDataBytes [expr {3 * $xSize * $ySize}] +set data [read $f $numDataBytes] +close $f +.CE .SH "SEE ALSO" -close(n), flush(n), gets(n), puts(n), read(n), socket(n), +close(n), flush(n), gets(n), open(n), puts(n), read(n), socket(n), Tcl_StandardChannels(3) - .SH KEYWORDS blocking, buffering, carriage return, end of line, flushing, linemode, newline, nonblocking, platform, translation, encoding, filter, byte array, binary +'\" Local Variables: +'\" mode: nroff +'\" End: |