diff options
Diffstat (limited to 'tcl/doc/open.n')
| -rw-r--r-- | tcl/doc/open.n | 44 |
1 files changed, 27 insertions, 17 deletions
diff --git a/tcl/doc/open.n b/tcl/doc/open.n index 39121b6c3e1..833ae11ef30 100644 --- a/tcl/doc/open.n +++ b/tcl/doc/open.n @@ -55,8 +55,9 @@ Open the file for reading and writing. Truncate it if it exists. If it doesn't exist, create a new file. .TP 15 \fBa\fR -Open the file for writing only. The file must already exist, and the file -is positioned so that new data is appended to the file. +Open the file for writing only. If the file doesn't exist, +create a new empty file. +Set the initial access position to the end of the file. .TP 15 \fBa+\fR Open the file for reading and writing. If the file doesn't exist, @@ -144,6 +145,23 @@ number of data bits, and number of stop bits for this serial port. The ``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\-pollinterval \fImsec\fR +. +This option, available only on Windows for serial ports, 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 often than 10 msec (the default). +.TP +\fB\-lasterror\fR +. +This option is available only on Windows for serial ports, and is +query only (will only be reported when directly requested). +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 (e.g. FRAME RXOVER). .VE .VS @@ -153,8 +171,13 @@ number of stop bits and should be the integer 1 or 2. \fBWindows \fR(all versions) . Valid values for \fIfileName\fR to open a serial port are of the form -\fBcom\fIX\fB:\fR, where \fIX\fR is a number, generally from 1 to 4. An -attempt to open a serial port that does not exist will fail. +\fBcom\fIX\fB:\fR, where \fIX\fR is a number, generally from 1 to 4. +This notation only works for serial ports from 1 to 9, if the system +happens to have more than four. An attempt to open a serial port that +does not exist or has a number greater than 9 will fail. An alternate +form of opening serial ports is to use the filename \fB\e\e.\ecomX\fR, +where X is any number that corresponds to a serial port; please note +that this method is considerably slower on Windows 95 and Windows 98. .TP \fBWindows NT\fR . @@ -202,19 +225,6 @@ application, no data will be sent to the command pipeline's standard output until the pipe is actually closed. This problem occurs because 16-bit DOS applications are run synchronously, as described above. .TP -\fBWindows 3.X\fR -. -A command pipeline can execute 16-bit or 32-bit DOS or Windows -applications, but the call to \fBopen\fR will not return until the last -program in the pipeline has finished executing; command pipelines run -synchronously. If the pipeline is opened with write access (either just -writing or both reading and writing) the first application in the -pipeline will instead see an immediate end-of-file; any data the caller -writes to the open pipe will instead be discarded. -.sp -Since Tcl cannot be run with a real console under Windows 3.X, there are -no interactions between command pipelines and the console. -.TP \fBMacintosh\fR . Opening a serial port is not currently implemented under Macintosh. |