'\" '\" Copyright (c) 1989-1993 The Regents of the University of California. '\" Copyright (c) 1994-1996 Sun Microsystems, Inc. '\" '\" See the file "license.terms" for information on usage and redistribution '\" of this file, and for a DISCLAIMER OF ALL WARRANTIES. '\" '\" SCCS: @(#) CrtCommand.3 1.22 96/03/25 19:58:44 '\" '\" The definitions below are for supplemental macros used in Tcl/Tk '\" manual entries. '\" '\" .AP type name in/out ?indent? '\" Start paragraph describing an argument to a library procedure. '\" type is type of argument (int, etc.), in/out is either "in", "out", '\" or "in/out" to describe whether procedure reads or modifies arg, '\" and indent is equivalent to second arg of .IP (shouldn't ever be '\" needed; use .AS below instead) '\" '\" .AS ?type? ?name? '\" Give maximum sizes of arguments for setting tab stops. Type and '\" name are examples of largest possible arguments that will be passed '\" to .AP later. If args are omitted, default tab stops are used. '\" '\" .BS '\" Start box enclosure. From here until next .BE, everything will be '\" enclosed in one large box. '\" '\" .BE '\" End of box enclosure. '\" '\" .CS '\" Begin code excerpt. '\" '\" .CE '\" End code excerpt. '\" '\" .VS ?br? '\" Begin vertical sidebar, for use in marking newly-changed parts '\" of man pages. If an argument is present, then a line break is '\" forced before starting the sidebar. '\" '\" .VE '\" End of vertical sidebar. '\" '\" .DS '\" Begin an indented unfilled display. '\" '\" .DE '\" End of indented unfilled display. '\" '\" .SO '\" Start of list of standard options for a Tk widget. The '\" options follow on successive lines, in four columns separated '\" by tabs. '\" '\" .SE '\" End of list of standard options for a Tk widget. '\" '\" .OP cmdName dbName dbClass '\" Start of description of a specific option. cmdName gives the '\" option's name as specified in the class command, dbName gives '\" the option's name in the option database, and dbClass gives '\" the option's class in the option database. '\" '\" .UL arg1 arg2 '\" Print arg1 underlined, then print arg2 normally. '\" '\" SCCS: @(#) man.macros 1.8 96/02/15 20:02:24 '\" '\" # Set up traps and other miscellaneous stuff for Tcl/Tk man pages. .if t .wh -1.3i ^B .nr ^l \n(.l .ad b '\" # Start an argument description .de AP .ie !"\\$4"" .TP \\$4 .el \{\ . ie !"\\$2"" .TP \\n()Cu . el .TP 15 .\} .ie !"\\$3"" \{\ .ta \\n()Au \\n()Bu \&\\$1 \\fI\\$2\\fP (\\$3) .\".b .\} .el \{\ .br .ie !"\\$2"" \{\ \&\\$1 \\fI\\$2\\fP .\} .el \{\ \&\\fI\\$1\\fP .\} .\} .. '\" # define tabbing values for .AP .de AS .nr )A 10n .if !"\\$1"" .nr )A \\w'\\$1'u+3n .nr )B \\n()Au+15n .\" .if !"\\$2"" .nr )B \\w'\\$2'u+\\n()Au+3n .nr )C \\n()Bu+\\w'(in/out)'u+2n .. .AS Tcl_Interp Tcl_CreateInterp in/out '\" # BS - start boxed text '\" # ^y = starting y location '\" # ^b = 1 .de BS .br .mk ^y .nr ^b 1u .if n .nf .if n .ti 0 .if n \l'\\n(.lu\(ul' .if n .fi .. '\" # BE - end boxed text (draw box now) .de BE .nf .ti 0 .mk ^t .ie n \l'\\n(^lu\(ul' .el \{\ .\" Draw four-sided box normally, but don't draw top of .\" box if the box started on an earlier page. .ie !\\n(^b-1 \{\ \h'-1.5n'\L'|\\n(^yu-1v'\l'\\n(^lu+3n\(ul'\L'\\n(^tu+1v-\\n(^yu'\l'|0u-1.5n\(ul' .\} .el \}\ \h'-1.5n'\L'|\\n(^yu-1v'\h'\\n(^lu+3n'\L'\\n(^tu+1v-\\n(^yu'\l'|0u-1.5n\(ul' .\} .\} .fi .br .nr ^b 0 .. '\" # VS - start vertical sidebar '\" # ^Y = starting y location '\" # ^v = 1 (for troff; for nroff this doesn't matter) .de VS .if !"\\$1"" .br .mk ^Y .ie n 'mc \s12\(br\s0 .el .nr ^v 1u .. '\" # VE - end of vertical sidebar .de VE .ie n 'mc .el \{\ .ev 2 .nf .ti 0 .mk ^t \h'|\\n(^lu+3n'\L'|\\n(^Yu-1v\(bv'\v'\\n(^tu+1v-\\n(^Yu'\h'-|\\n(^lu+3n' .sp -1 .fi .ev .\} .nr ^v 0 .. '\" # Special macro to handle page bottom: finish off current '\" # box/sidebar if in box/sidebar mode, then invoked standard '\" # page bottom macro. .de ^B .ev 2 'ti 0 'nf .mk ^t .if \\n(^b \{\ .\" Draw three-sided box if this is the box's first page, .\" draw two sides but no top otherwise. .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 .el \h'-1.5n'\L'|\\n(^yu-1v'\h'\\n(^lu+3n'\L'\\n(^tu+1v-\\n(^yu'\h'|0u'\c .\} .if \\n(^v \{\ .nr ^x \\n(^tu+1v-\\n(^Yu \kx\h'-\\nxu'\h'|\\n(^lu+3n'\ky\L'-\\n(^xu'\v'\\n(^xu'\h'|0u'\c .\} .bp 'fi .ev .if \\n(^b \{\ .mk ^y .nr ^b 2 .\} .if \\n(^v \{\ .mk ^Y .\} .. '\" # DS - begin display .de DS .RS .nf .sp .. '\" # DE - end display .de DE .fi .RE .sp .. '\" # SO - start of list of standard options .de SO .SH "STANDARD OPTIONS" .LP .nf .ta 4c 8c 12c .ft B .. '\" # SE - end of list of standard options .de SE .fi .ft R .LP See the \\fBoptions\\fR manual entry for details on the standard options. .. '\" # OP - start of full description for a single option .de OP .LP .nf .ta 4c Command-Line Name: \\fB\\$1\\fR Database Name: \\fB\\$2\\fR Database Class: \\fB\\$3\\fR .fi .IP .. '\" # CS - begin code excerpt .de CS .RS .nf .ta .25i .5i .75i 1i .. '\" # CE - end code excerpt .de CE .fi .RE .. .de UL \\$1\l'|0\(ul'\\$2 .. .TH Tcl_CreateCommand 3 "" Tcl "Tcl Library Procedures" .BS .SH NAME Tcl_CreateCommand, Tcl_DeleteCommand, Tcl_GetCommandInfo, Tcl_SetCommandInfo \- implement new commands in C .SH SYNOPSIS .nf \fB#include \fR .sp .VS .VE Tcl_Command \fBTcl_CreateCommand\fR(\fIinterp, cmdName, proc, clientData, deleteProc\fR) .sp int \fBTcl_DeleteCommand\fR(\fIinterp, cmdName\fR) .sp .VS int \fBTcl_GetCommandInfo\fR(\fIinterp, cmdName, infoPtr\fR) .sp int \fBTcl_SetCommandInfo\fR(\fIinterp, cmdName, infoPtr\fR) .sp .VS char * \fBTcl_GetCommandName\fR(\fIinterp, token\fR) .VE .VE .SH ARGUMENTS .AS Tcl_CmdDeleteProc **deleteProcPtr .AP Tcl_Interp *interp in Interpreter in which to create new command. .AP char *cmdName in Name of command. .AP Tcl_CmdProc *proc in Implementation of new command: \fIproc\fR will be called whenever \fIcmdName\fR is invoked as a command. .AP ClientData clientData in Arbitrary one-word value to pass to \fIproc\fR and \fIdeleteProc\fR. .AP Tcl_CmdDeleteProc *deleteProc in Procedure to call before \fIcmdName\fR is deleted from the interpreter; allows for command-specific cleanup. If NULL, then no procedure is called before the command is deleted. .AP Tcl_CmdInfo *infoPtr in/out .VS Pointer to structure containing various information about a Tcl command. .AP Tcl_Command token in Token for command, returned by previous call to \fBTcl_CreateCommand\fR. The command must not have been deleted. .VE .BE .SH DESCRIPTION .PP \fBTcl_CreateCommand\fR defines a new command in \fIinterp\fR and associates it with procedure \fIproc\fR such that whenever \fIcmdName\fR is invoked as a Tcl command (via a call to \fBTcl_Eval\fR) the Tcl interpreter will call \fIproc\fR to process the command. If there is already a command \fIcmdName\fR associated with the interpreter, it is deleted. .VS \fBTcl_CreateCommand\fR returns a token that may be used to refer to the command in subsequent calls to \fBTcl_GetCommandName\fR. If \fBTcl_CreateCommand\fR is called for an interpreter that is in the process of being deleted, then it does not create a new command and it returns NULL. .VE \fIProc\fR should have arguments and result that match the type \fBTcl_CmdProc\fR: .CS typedef int Tcl_CmdProc( ClientData \fIclientData\fR, Tcl_Interp *\fIinterp\fR, int \fIargc\fR, char *\fIargv\fR[]); .CE When \fIproc\fR is invoked the \fIclientData\fR and \fIinterp\fR parameters will be copies of the \fIclientData\fR and \fIinterp\fR arguments given to \fBTcl_CreateCommand\fR. Typically, \fIclientData\fR points to an application-specific data structure that describes what to do when the command procedure is invoked. \fIArgc\fR and \fIargv\fR describe the arguments to the command, \fIargc\fR giving the number of arguments (including the command name) and \fIargv\fR giving the values of the arguments as strings. The \fIargv\fR array will contain \fIargc\fR+1 values; the first \fIargc\fR values point to the argument strings, and the last value is NULL. .PP \fIProc\fR must return an integer code that is either \fBTCL_OK\fR, \fBTCL_ERROR\fR, \fBTCL_RETURN\fR, \fBTCL_BREAK\fR, or \fBTCL_CONTINUE\fR. See the Tcl overview man page for details on what these codes mean. Most normal commands will only return \fBTCL_OK\fR or \fBTCL_ERROR\fR. In addition, \fIproc\fR must set \fIinterp->result\fR to point to a string value; in the case of a \fBTCL_OK\fR return code this gives the result of the command, and in the case of \fBTCL_ERROR\fR it gives an error message. The \fBTcl_SetResult\fR procedure provides an easy interface for setting the return value; for complete details on how the \fIinterp->result\fR field is managed, see the \fBTcl_Interp\fR man page. Before invoking a command procedure, \fBTcl_Eval\fR sets \fIinterp->result\fR to point to an empty string, so simple commands can return an empty result by doing nothing at all. .PP .VS The contents of the \fIargv\fR array belong to Tcl and are not guaranteed to persist once \fIproc\fR returns: \fIproc\fR should not modify them, nor should it set \fIinterp->result\fR to point anywhere within the \fIargv\fR values. Call \fBTcl_SetResult\fR with status \fBTCL_VOLATILE\fR if you want to return something from the \fIargv\fR array. .VE .PP \fIDeleteProc\fR will be invoked when (if) \fIcmdName\fR is deleted. This can occur through a call to \fBTcl_DeleteCommand\fR or \fBTcl_DeleteInterp\fR, or by replacing \fIcmdName\fR in another call to \fBTcl_CreateCommand\fR. \fIDeleteProc\fR is invoked before the command is deleted, and gives the application an opportunity to release any structures associated with the command. \fIDeleteProc\fR should have arguments and result that match the type \fBTcl_CmdDeleteProc\fR: .CS typedef void Tcl_CmdDeleteProc(ClientData \fIclientData\fR); .CE The \fIclientData\fR argument will be the same as the \fIclientData\fR argument passed to \fBTcl_CreateCommand\fR. .PP \fBTcl_DeleteCommand\fR deletes a command from a command interpreter. Once the call completes, attempts to invoke \fIcmdName\fR in \fIinterp\fR will result in errors. If \fIcmdName\fR isn't bound as a command in \fIinterp\fR then \fBTcl_DeleteCommand\fR does nothing and returns -1; otherwise it returns 0. There are no restrictions on \fIcmdName\fR: it may refer to a built-in command, an application-specific command, or a Tcl procedure. .PP .VS \fBTcl_GetCommandInfo\fR checks to see whether its \fIcmdName\fR argument exists as a command in \fIinterp\fR. If not then it returns 0. Otherwise it places information about the command in the structure pointed to by \fIinfoPtr\fR and returns 1. Tcl_CmdInfo structures have fields named \fIproc\fR, \fIclientData\fR, and \fIdeleteProc\fR, which have the same meaning as the corresponding arguments to \fBTcl_CreateCommand\fR. There is also a field \fIdeleteData\fR, which is the ClientData value to pass to \fIdeleteProc\fR; it is normally the same as \fIclientData\fR but may be set independently using the \fBTcl_SetCommandInfo\fR procedure. .PP \fBTcl_SetCommandInfo\fR is used to modify the procedures and ClientData values associated with a command. Its \fIcmdName\fR argument is the name of a command in \fIinterp\fR. If this command does not exist then \fBTcl_SetCommandInfo\fR returns 0. Otherwise, it copies the information from \fI*infoPtr\fR to Tcl's internal structure for the command and returns 1. Note that this procedure allows the ClientData for a command's deletion procedure to be given a different value than the ClientData for its command procedure. .PP \fBTcl_GetCommandName\fR provides a mechanism for tracking commands that have been renamed. Given a token returned by \fBTcl_CreateCommand\fR when the command was created, \fBTcl_GetCommandName\fR returns the string name of the command. If the command has been renamed since it was created, then \fBTcl_GetCommandName\fR returns the current name. The command corresponding to \fItoken\fR must not have been deleted. The string returned by \fBTcl_GetCommandName\fR is in dynamic memory owned by Tcl and is only guaranteed to retain its value as long as the command isn't deleted or renamed; callers should copy the string if they need to keep it for a long time. .VE .SH KEYWORDS bind, command, create, delete, interpreter