'\" '\" 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: @(#) SetResult.3 1.18 96/03/25 20:06:54 '\" '\" 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_SetResult 3 7.0 Tcl "Tcl Library Procedures" .BS .SH NAME Tcl_SetResult, Tcl_AppendResult, Tcl_AppendElement, Tcl_ResetResult \- manipulate Tcl result string .SH SYNOPSIS .nf \fB#include \fR .sp \fBTcl_SetResult\fR(\fIinterp, string, freeProc\fR) .sp \fBTcl_AppendResult(\fIinterp, string, string, ... , \fB(char *) NULL\fR) .sp .VS \fBTcl_AppendElement\fR(\fIinterp, string\fR) .VE .sp \fBTcl_ResetResult\fR(\fIinterp\fR) .sp \fBTcl_FreeResult\fR(\fIinterp\fR) .SH ARGUMENTS .AS Tcl_FreeProc freeProc .AP Tcl_Interp *interp out Interpreter whose result is to be modified. .AP char *string in String value to become result for \fIinterp\fR or to be appended to existing result. .AP Tcl_FreeProc *freeProc in Address of procedure to call to release storage at \fIstring\fR, or \fBTCL_STATIC\fR, \fBTCL_DYNAMIC\fR, or \fBTCL_VOLATILE\fR. .BE .SH DESCRIPTION .PP The procedures described here are utilities for setting the result/error string in a Tcl interpreter. .PP \fBTcl_SetResult\fR arranges for \fIstring\fR to be the return string for the current Tcl command in \fIinterp\fR, replacing any existing result. If \fIfreeProc\fR is \fBTCL_STATIC\fR it means that \fIstring\fR refers to an area of static storage that is guaranteed not to be modified until at least the next call to \fBTcl_Eval\fR. If \fIfreeProc\fR is \fBTCL_DYNAMIC\fR it means that \fIstring\fR was allocated with a call to \fBmalloc()\fR and is now the property of the Tcl system. \fBTcl_SetResult\fR will arrange for the string's storage to be released by calling \fBfree()\fR when it is no longer needed. If \fIfreeProc\fR is \fBTCL_VOLATILE\fR it means that \fIstring\fR points to an area of memory that is likely to be overwritten when \fBTcl_SetResult\fR returns (e.g. it points to something in a stack frame). In this case \fBTcl_SetResult\fR will make a copy of the string in dynamically allocated storage and arrange for the copy to be the return string for the current Tcl command. .PP If \fIfreeProc\fR isn't one of the values \fBTCL_STATIC\fR, \fBTCL_DYNAMIC\fR, and \fBTCL_VOLATILE\fR, then it is the address of a procedure that Tcl should call to free the string. This allows applications to use non-standard storage allocators. When Tcl no longer needs the storage for the string, it will call \fIfreeProc\fR. \fIFreeProc\fR should have arguments and result that match the type \fBTcl_FreeProc\fR: .CS typedef void Tcl_FreeProc(char *\fIblockPtr\fR); .CE When \fIfreeProc\fR is called, its \fIblockPtr\fR will be set to the value of \fIstring\fR passed to \fBTcl_SetResult\fR. .PP If \fIstring\fR is \fBNULL\fR, then \fIfreeProc\fR is ignored and \fBTcl_SetResult\fR re-initializes \fIinterp\fR's result to point to the pre-allocated result area, with an empty string in the result area. .PP If \fBTcl_SetResult\fR is called at a time when \fIinterp\fR holds a result, \fBTcl_SetResult\fR does whatever is necessary to dispose of the old result (see the \fBTcl_Interp\fR manual entry for details on this). .PP \fBTcl_AppendResult\fR makes it easy to build up Tcl results in pieces. It takes each of its \fIstring\fR arguments and appends them in order to the current result associated with \fIinterp\fR. If the result is in its initialized empty state (e.g. a command procedure was just invoked or \fBTcl_ResetResult\fR was just called), then \fBTcl_AppendResult\fR sets the result to the concatenation of its \fIstring\fR arguments. \fBTcl_AppendResult\fR may be called repeatedly as additional pieces of the result are produced. \fBTcl_AppendResult\fR takes care of all the storage management issues associated with managing \fIinterp\fR's result, such as allocating a larger result area if necessary. Any number of \fIstring\fR arguments may be passed in a single call; the last argument in the list must be a NULL pointer. .PP \fBTcl_AppendElement\fR is similar to \fBTcl_AppendResult\fR in that it allows results to be built up in pieces. However, \fBTcl_AppendElement\fR takes only a single \fIstring\fR argument and it appends that argument to the current result as a proper Tcl list element. \fBTcl_AppendElement\fR adds backslashes or braces if necessary to ensure that \fIinterp\fR's result can be parsed as a list and that \fIstring\fR will be extracted as a single element. Under normal conditions, \fBTcl_AppendElement\fR will add a space character to \fIinterp\fR's result just before adding the new list element, so that the list elements in the result are properly separated. .VS However if the new list element is the first in a list or sub-list (i.e. \fIinterp\fR's current result is empty, or consists of the single character ``{'', or ends in the characters `` {'') then no space is added. .VE .PP \fBTcl_ResetResult\fR clears the result for \fIinterp\fR, freeing the memory associated with it if the current result was dynamically allocated. It leaves the result in its normal initialized state with \fIinterp->result\fR pointing to a static buffer containing \fBTCL_RESULT_SIZE\fR characters, of which the first character is zero. \fBTcl_ResetResult\fR also clears the error state managed by \fBTcl_AddErrorInfo\fR and \fBTcl_SetErrorCode\fR. .PP \fBTcl_FreeResult\fR is a macro that performs part of the work of \fBTcl_ResetResult\fR. It frees up the memory associated with \fIinterp\fR's result and sets \fIinterp->freeProc\fR to zero, but it doesn't change \fIinterp->result\fR or clear error state. \fBTcl_FreeResult\fR is most commonly used when a procedure is about to replace one result value with another. .SH "SEE ALSO" Tcl_AddErrorInfo, Tcl_SetErrorCode, Tcl_Interp .SH KEYWORDS append, command, element, list, result, return value, interpreter