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author | William Joye <wjoye@cfa.harvard.edu> | 2018-12-25 17:45:11 (GMT) |
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committer | William Joye <wjoye@cfa.harvard.edu> | 2018-12-25 17:45:11 (GMT) |
commit | 5f5fd2864a3193a8d5da12fcb92ba7379084c286 (patch) | |
tree | bcdca927ed2a7b05c647b9a6bfdfd4a7ca5c730e /tcl8.6/doc/CrtFileHdlr.3 | |
parent | 535baffcecf6e738102fc12cda0109bc963e150f (diff) | |
download | blt-5f5fd2864a3193a8d5da12fcb92ba7379084c286.zip blt-5f5fd2864a3193a8d5da12fcb92ba7379084c286.tar.gz blt-5f5fd2864a3193a8d5da12fcb92ba7379084c286.tar.bz2 |
update tcl/tk
Diffstat (limited to 'tcl8.6/doc/CrtFileHdlr.3')
-rw-r--r-- | tcl8.6/doc/CrtFileHdlr.3 | 91 |
1 files changed, 0 insertions, 91 deletions
diff --git a/tcl8.6/doc/CrtFileHdlr.3 b/tcl8.6/doc/CrtFileHdlr.3 deleted file mode 100644 index c1bc1fa..0000000 --- a/tcl8.6/doc/CrtFileHdlr.3 +++ /dev/null @@ -1,91 +0,0 @@ -'\" -'\" Copyright (c) 1990-1994 The Regents of the University of California. -'\" Copyright (c) 1994-1997 Sun Microsystems, Inc. -'\" -'\" See the file "license.terms" for information on usage and redistribution -'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES. -'\" -.TH Tcl_CreateFileHandler 3 8.0 Tcl "Tcl Library Procedures" -.so man.macros -.BS -.SH NAME -Tcl_CreateFileHandler, Tcl_DeleteFileHandler \- associate procedure callbacks with files or devices (Unix only) -.SH SYNOPSIS -.nf -\fB#include <tcl.h>\fR -.sp -\fBTcl_CreateFileHandler\fR(\fIfd, mask, proc, clientData\fR) -.sp -\fBTcl_DeleteFileHandler\fR(\fIfd\fR) -.SH ARGUMENTS -.AS Tcl_FileProc clientData -.AP int fd in -Unix file descriptor for an open file or device. -.AP int mask in -Conditions under which \fIproc\fR should be called: -OR-ed combination of \fBTCL_READABLE\fR, \fBTCL_WRITABLE\fR, -and \fBTCL_EXCEPTION\fR. May be set to 0 to temporarily disable -a handler. -.AP Tcl_FileProc *proc in -Procedure to invoke whenever the file or device indicated -by \fIfile\fR meets the conditions specified by \fImask\fR. -.AP ClientData clientData in -Arbitrary one-word value to pass to \fIproc\fR. -.BE -.SH DESCRIPTION -.PP -\fBTcl_CreateFileHandler\fR arranges for \fIproc\fR to be -invoked in the future whenever I/O becomes possible on a file -or an exceptional condition exists for the file. The file -is indicated by \fIfd\fR, and the conditions of interest -are indicated by \fImask\fR. For example, if \fImask\fR -is \fBTCL_READABLE\fR, \fIproc\fR will be called when -the file is readable. -The callback to \fIproc\fR is made by \fBTcl_DoOneEvent\fR, so -\fBTcl_CreateFileHandler\fR is only useful in programs that dispatch -events through \fBTcl_DoOneEvent\fR or through Tcl commands such -as \fBvwait\fR. -.PP -\fIProc\fR should have arguments and result that match the -type \fBTcl_FileProc\fR: -.PP -.CS -typedef void \fBTcl_FileProc\fR( - ClientData \fIclientData\fR, - int \fImask\fR); -.CE -.PP -The \fIclientData\fR parameter to \fIproc\fR is a copy -of the \fIclientData\fR -argument given to \fBTcl_CreateFileHandler\fR when the callback -was created. Typically, \fIclientData\fR points to a data -structure containing application-specific information about -the file. \fIMask\fR is an integer mask indicating which -of the requested conditions actually exists for the file; it -will contain a subset of the bits in the \fImask\fR argument -to \fBTcl_CreateFileHandler\fR. -.PP -There may exist only one handler for a given file at a given time. -If \fBTcl_CreateFileHandler\fR is called when a handler already -exists for \fIfd\fR, then the new callback replaces the information -that was previously recorded. -.PP -\fBTcl_DeleteFileHandler\fR may be called to delete the -file handler for \fIfd\fR; if no handler exists for the -file given by \fIfd\fR then the procedure has no effect. -.PP -The purpose of file handlers is to enable an application to respond to -events while waiting for files to become ready for I/O. For this to work -correctly, the application may need to use non-blocking I/O operations on -the files for which handlers are declared. Otherwise the application may -block if it reads or writes too much data; while waiting for the I/O to -complete the application will not be able to service other events. Use -\fBTcl_SetChannelOption\fR with \fB\-blocking\fR to set the channel into -blocking or nonblocking mode as required. -.PP -Note that these interfaces are only supported by the Unix -implementation of the Tcl notifier. -.SH "SEE ALSO" -fileevent(n), Tcl_CreateTimerHandler(3), Tcl_DoWhenIdle(3) -.SH KEYWORDS -callback, file, handler |