2 '\" Copyright (c) 1993 The Regents of the University of California.
3 '\" Copyright (c) 1994-1996 Sun Microsystems, Inc.
5 '\" See the file "license.terms" for information on usage and redistribution
6 '\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
8 '\" RCS: @(#) $Id: LinkVar.3,v 1.6.2.1 2003/07/18 16:56:24 dgp Exp $
10 '\" The definitions below are for supplemental macros used in Tcl/Tk
13 '\" .AP type name in/out ?indent?
14 '\" Start paragraph describing an argument to a library procedure.
15 '\" type is type of argument (int, etc.), in/out is either "in", "out",
16 '\" or "in/out" to describe whether procedure reads or modifies arg,
17 '\" and indent is equivalent to second arg of .IP (shouldn't ever be
18 '\" needed; use .AS below instead)
21 '\" Give maximum sizes of arguments for setting tab stops. Type and
22 '\" name are examples of largest possible arguments that will be passed
23 '\" to .AP later. If args are omitted, default tab stops are used.
26 '\" Start box enclosure. From here until next .BE, everything will be
27 '\" enclosed in one large box.
30 '\" End of box enclosure.
33 '\" Begin code excerpt.
38 '\" .VS ?version? ?br?
39 '\" Begin vertical sidebar, for use in marking newly-changed parts
40 '\" of man pages. The first argument is ignored and used for recording
41 '\" the version when the .VS was added, so that the sidebars can be
42 '\" found and removed when they reach a certain age. If another argument
43 '\" is present, then a line break is forced before starting the sidebar.
46 '\" End of vertical sidebar.
49 '\" Begin an indented unfilled display.
52 '\" End of indented unfilled display.
55 '\" Start of list of standard options for a Tk widget. The
56 '\" options follow on successive lines, in four columns separated
60 '\" End of list of standard options for a Tk widget.
62 '\" .OP cmdName dbName dbClass
63 '\" Start of description of a specific option. cmdName gives the
64 '\" option's name as specified in the class command, dbName gives
65 '\" the option's name in the option database, and dbClass gives
66 '\" the option's class in the option database.
69 '\" Print arg1 underlined, then print arg2 normally.
71 '\" RCS: @(#) $Id: man.macros,v 1.4 2000/08/25 06:18:32 ericm Exp $
73 '\" # Set up traps and other miscellaneous stuff for Tcl/Tk man pages.
77 '\" # Start an argument description
81 . ie !"\\$2"" .TP \\n()Cu
86 \&\\$1 \\fI\\$2\\fP (\\$3)
99 '\" # define tabbing values for .AP
102 .if !"\\$1"" .nr )A \\w'\\$1'u+3n
105 .if !"\\$2"" .nr )B \\w'\\$2'u+\\n()Au+3n
106 .nr )C \\n()Bu+\\w'(in/out)'u+2n
108 .AS Tcl_Interp Tcl_CreateInterp in/out
109 '\" # BS - start boxed text
110 '\" # ^y = starting y location
118 .if n \l'\\n(.lu\(ul'
121 '\" # BE - end boxed text (draw box now)
126 .ie n \l'\\n(^lu\(ul'
128 .\" Draw four-sided box normally, but don't draw top of
129 .\" box if the box started on an earlier page.
131 \h'-1.5n'\L'|\\n(^yu-1v'\l'\\n(^lu+3n\(ul'\L'\\n(^tu+1v-\\n(^yu'\l'|0u-1.5n\(ul'
134 \h'-1.5n'\L'|\\n(^yu-1v'\h'\\n(^lu+3n'\L'\\n(^tu+1v-\\n(^yu'\l'|0u-1.5n\(ul'
141 '\" # VS - start vertical sidebar
142 '\" # ^Y = starting y location
143 '\" # ^v = 1 (for troff; for nroff this doesn't matter)
147 .ie n 'mc \s12\(br\s0
150 '\" # VE - end of vertical sidebar
158 \h'|\\n(^lu+3n'\L'|\\n(^Yu-1v\(bv'\v'\\n(^tu+1v-\\n(^Yu'\h'-|\\n(^lu+3n'
165 '\" # Special macro to handle page bottom: finish off current
166 '\" # box/sidebar if in box/sidebar mode, then invoked standard
167 '\" # page bottom macro.
174 .\" Draw three-sided box if this is the box's first page,
175 .\" draw two sides but no top otherwise.
176 .ie !\\n(^b-1 \h'-1.5n'\L'|\\n(^yu-1v'\l'\\n(^lu+3n\(ul'\L'\\n(^tu+1v-\\n(^yu'\h'|0u'\c
177 .el \h'-1.5n'\L'|\\n(^yu-1v'\h'\\n(^lu+3n'\L'\\n(^tu+1v-\\n(^yu'\h'|0u'\c
180 .nr ^x \\n(^tu+1v-\\n(^Yu
181 \kx\h'-\\nxu'\h'|\\n(^lu+3n'\ky\L'-\\n(^xu'\v'\\n(^xu'\h'|0u'\c
194 '\" # DS - begin display
200 '\" # DE - end display
206 '\" # SO - start of list of standard options
208 .SH "STANDARD OPTIONS"
214 '\" # SE - end of list of standard options
219 See the \\fBoptions\\fR manual entry for details on the standard options.
221 '\" # OP - start of full description for a single option
226 Command-Line Name: \\fB\\$1\\fR
227 Database Name: \\fB\\$2\\fR
228 Database Class: \\fB\\$3\\fR
232 '\" # CS - begin code excerpt
238 '\" # CE - end code excerpt
246 .TH Tcl_LinkVar 3 7.5 Tcl "Tcl Library Procedures"
249 Tcl_LinkVar, Tcl_UnlinkVar, Tcl_UpdateLinkedVar \- link Tcl variable to C variable
252 \fB#include <tcl.h>\fR
255 \fBTcl_LinkVar\fR(\fIinterp, varName, addr, type\fR)
257 \fBTcl_UnlinkVar\fR(\fIinterp, varName\fR)
259 \fBTcl_UpdateLinkedVar\fR(\fIinterp, varName\fR)
261 .AS Tcl_Interp writable
262 .AP Tcl_Interp *interp in
263 Interpreter that contains \fIvarName\fR.
264 Also used by \fBTcl_LinkVar\fR to return error messages.
265 .AP "CONST char" *varName in
266 Name of global variable.
268 Address of C variable that is to be linked to \fIvarName\fR.
270 Type of C variable. Must be one of TCL_LINK_INT, TCL_LINK_DOUBLE,
274 TCL_LINK_BOOLEAN, or TCL_LINK_STRING, optionally OR'ed with
275 TCL_LINK_READ_ONLY to make Tcl variable read-only.
280 \fBTcl_LinkVar\fR uses variable traces to keep the Tcl variable
281 named by \fIvarName\fR in sync with the C variable at the address
283 Whenever the Tcl variable is read the value of the C variable will
284 be returned, and whenever the Tcl variable is written the C
285 variable will be updated to have the same value.
286 \fBTcl_LinkVar\fR normally returns TCL_OK; if an error occurs
287 while setting up the link (e.g. because \fIvarName\fR is the
288 name of array) then TCL_ERROR is returned and the interpreter's result
289 contains an error message.
291 The \fItype\fR argument specifies the type of the C variable,
292 and must have one of the following values, optionally OR'ed with
296 The C variable is of type \fBint\fR.
297 Any value written into the Tcl variable must have a proper integer
298 form acceptable to \fBTcl_GetIntFromObj\fR; attempts to write
299 non-integer values into \fIvarName\fR will be rejected with
302 \fBTCL_LINK_DOUBLE\fR
303 The C variable is of type \fBdouble\fR.
304 Any value written into the Tcl variable must have a proper real
305 form acceptable to \fBTcl_GetDoubleFromObj\fR; attempts to write
306 non-real values into \fIvarName\fR will be rejected with
309 \fBTCL_LINK_WIDE_INT\fR
311 The C variable is of type \fBTcl_WideInt\fR (which is an integer type
312 at least 64-bits wide on all platforms that can support it.)
313 Any value written into the Tcl variable must have a proper integer
314 form acceptable to \fBTcl_GetWideIntFromObj\fR; attempts to write
315 non-integer values into \fIvarName\fR will be rejected with
319 \fBTCL_LINK_BOOLEAN\fR
320 The C variable is of type \fBint\fR.
321 If its value is zero then it will read from Tcl as ``0'';
322 otherwise it will read from Tcl as ``1''.
323 Whenever \fIvarName\fR is
324 modified, the C variable will be set to a 0 or 1 value.
325 Any value written into the Tcl variable must have a proper boolean
326 form acceptable to \fBTcl_GetBooleanFromObj\fR; attempts to write
327 non-boolean values into \fIvarName\fR will be rejected with
330 \fBTCL_LINK_STRING\fR
331 The C variable is of type \fBchar *\fR.
333 If its value is not NULL then it must be a pointer to a string
334 allocated with \fBTcl_Alloc\fR or \fBckalloc\fR.
336 Whenever the Tcl variable is modified the current C string will be
337 freed and new memory will be allocated to hold a copy of the variable's
339 If the C variable contains a NULL pointer then the Tcl variable
340 will read as ``NULL''.
342 If the TCL_LINK_READ_ONLY flag is present in \fItype\fR then the
343 variable will be read-only from Tcl, so that its value can only be
344 changed by modifying the C variable.
345 Attempts to write the variable from Tcl will be rejected with errors.
347 \fBTcl_UnlinkVar\fR removes the link previously set up for the
348 variable given by \fIvarName\fR. If there does not exist a link
349 for \fIvarName\fR then the procedure has no effect.
351 \fBTcl_UpdateLinkedVar\fR may be invoked after the C variable has
352 changed to force the Tcl variable to be updated immediately.
353 In many cases this procedure is not needed, since any attempt to
354 read the Tcl variable will return the latest value of the C variable.
355 However, if a trace has been set on the Tcl variable (such as a
356 Tk widget that wishes to display the value of the variable), the
357 trace will not trigger when the C variable has changed.
358 \fBTcl_UpdateLinkedVar\fR ensures that any traces on the Tcl
359 variable are invoked.
362 boolean, integer, link, read-only, real, string, traces, variable