man/man3/Tcl_SaveResult.3 - toolchains/skids - Git at Google

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 '\" Copyright (c) 1997 by Sun Microsystems, Inc.
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 '\" RCS: @(#) $Id: SaveResult.3,v 1.2 1999/04/16 00:46:33 stanton Exp $
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 '\" The definitions below are for supplemental macros used in Tcl/Tk
 '\" manual entries.
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 '\"	Start of description of a specific option.  cmdName gives the
 '\"	option's name as specified in the class command, dbName gives
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 '\" .UL arg1 arg2
 '\"	Print arg1 underlined, then print arg2 normally.
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 '\" RCS: @(#) $Id: man.macros,v 1.4 2000/08/25 06:18:32 ericm Exp $
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 '\"	# Set up traps and other miscellaneous stuff for Tcl/Tk man pages.
 .if t .wh -1.3i ^B
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 .ie !"\\$4"" .TP \\$4
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 .   ie !"\\$2"" .TP \\n()Cu
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 .AS Tcl_Interp Tcl_CreateInterp in/out
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 .\}
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 \h'-1.5n'\L'|\\n(^yu-1v'\h'\\n(^lu+3n'\L'\\n(^tu+1v-\\n(^yu'\l'|0u-1.5n\(ul'
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 .TH Tcl_SaveResult 3 8.1 Tcl "Tcl Library Procedures"
 .BS
 .SH NAME
 Tcl_SaveResult, Tcl_RestoreResult, Tcl_DiscardResult \- save and restore an interpreter's result
 .SH SYNOPSIS
 .nf
 \fB#include <tcl.h>\fR
 .sp
 \fBTcl_SaveResult(\fIinterp, statePtr\fB)\fR
 .sp
 \fBTcl_RestoreResult(\fIinterp, statePtr\fB)\fR
 .sp
 \fBTcl_DiscardResult(\fIstatePtr\fB)\fR
 .SH ARGUMENTS
 .AS Tcl_SavedResult statePtr
 .AP Tcl_Interp *interp in
 Interpreter for which state should be saved.
 .AP Tcl_SavedResult *statePtr in
 Pointer to location where interpreter result should be saved or restored.
 .BE

 .SH DESCRIPTION
 .PP
 These routines allows a C procedure to take a snapshot of the current
 interpreter result so that it can be restored after a call
 to \fBTcl_Eval\fR or some other routine that modifies the interpreter
 result.  These routines are passed a pointer to a structure that is
 used to store enough information to restore the interpreter result
 state.  This structure can be allocated on the stack of the calling
 procedure.  These routines do not save the state of any error
 information in the interpreter (e.g. the \fBerrorCode\fR or
 \fBerrorInfo\fR variables).
 .PP
 \fBTcl_SaveResult\fR moves the string and object results
 of \fIinterp\fR into the location specified by \fIstatePtr\fR.
 \fBTcl_SaveResult\fR clears the result for \fIinterp\fR and
 leaves the result in its normal empty initialized state.
 .PP
 \fBTcl_RestoreResult\fR moves the string and object results from
 \fIstatePtr\fR back into \fIinterp\fR.  Any result or error that was
 already in the interpreter will be cleared.  The \fIstatePtr\fR is left
 in an uninitialized state and cannot be used until another call to
 \fBTcl_SaveResult\fR.
 .PP
 \fBTcl_DiscardResult\fR releases the saved interpreter state
 stored at \fBstatePtr\fR.  The state structure is left in an
 uninitialized state and cannot be used until another call to
 \fBTcl_SaveResult\fR.
 .PP
 Once \fBTcl_SaveResult\fR is called to save the interpreter
 result, either \fBTcl_RestoreResult\fR or
 \fBTcl_DiscardResult\fR must be called to properly clean up the
 memory associated with the saved state.

 .SH KEYWORDS
 result, state, interp
	'\"
	'\" Copyright (c) 1997 by Sun Microsystems, Inc.
	'\"
	'\" See the file "license.terms" for information on usage and redistribution
	'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
	'\"
	'\" RCS: @(#) $Id: SaveResult.3,v 1.2 1999/04/16 00:46:33 stanton Exp $
	'\"
	'\" 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 ?version? ?br?
	'\" Begin vertical sidebar, for use in marking newly-changed parts
	'\" of man pages. The first argument is ignored and used for recording
	'\" the version when the .VS was added, so that the sidebars can be
	'\" found and removed when they reach a certain age. If another 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.
	'\"
	'\" RCS: @(#) $Id: man.macros,v 1.4 2000/08/25 06:18:32 ericm Exp $
	'\"
	'\" # 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
	.\}
	.ta \\n()Au \\n()Bu
	.ie !"\\$3"" \{\
	\&\\$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
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	.\" Draw four-sided box normally, but don't draw top of
	.\" box if the box started on an earlier page.
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	\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'
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	.\" draw two sides but no top otherwise.
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	.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
	.\}
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	'fi
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	.de SO
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	.LP
	.nf
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	.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
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	..
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	.de CS
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	..
	.de UL
	\\$1\l'\|0\(ul'\\$2
	..
	.TH Tcl_SaveResult 3 8.1 Tcl "Tcl Library Procedures"
	.BS
	.SH NAME
	Tcl_SaveResult, Tcl_RestoreResult, Tcl_DiscardResult \- save and restore an interpreter's result
	.SH SYNOPSIS
	.nf
	\fB#include <tcl.h>\fR
	.sp
	\fBTcl_SaveResult(\fIinterp, statePtr\fB)\fR
	.sp
	\fBTcl_RestoreResult(\fIinterp, statePtr\fB)\fR
	.sp
	\fBTcl_DiscardResult(\fIstatePtr\fB)\fR
	.SH ARGUMENTS
	.AS Tcl_SavedResult statePtr
	.AP Tcl_Interp *interp in
	Interpreter for which state should be saved.
	.AP Tcl_SavedResult *statePtr in
	Pointer to location where interpreter result should be saved or restored.
	.BE

	.SH DESCRIPTION
	.PP
	These routines allows a C procedure to take a snapshot of the current
	interpreter result so that it can be restored after a call
	to \fBTcl_Eval\fR or some other routine that modifies the interpreter
	result. These routines are passed a pointer to a structure that is
	used to store enough information to restore the interpreter result
	state. This structure can be allocated on the stack of the calling
	procedure. These routines do not save the state of any error
	information in the interpreter (e.g. the \fBerrorCode\fR or
	\fBerrorInfo\fR variables).
	.PP
	\fBTcl_SaveResult\fR moves the string and object results
	of \fIinterp\fR into the location specified by \fIstatePtr\fR.
	\fBTcl_SaveResult\fR clears the result for \fIinterp\fR and
	leaves the result in its normal empty initialized state.
	.PP
	\fBTcl_RestoreResult\fR moves the string and object results from
	\fIstatePtr\fR back into \fIinterp\fR. Any result or error that was
	already in the interpreter will be cleared. The \fIstatePtr\fR is left
	in an uninitialized state and cannot be used until another call to
	\fBTcl_SaveResult\fR.
	.PP
	\fBTcl_DiscardResult\fR releases the saved interpreter state
	stored at \fBstatePtr\fR. The state structure is left in an
	uninitialized state and cannot be used until another call to
	\fBTcl_SaveResult\fR.
	.PP
	Once \fBTcl_SaveResult\fR is called to save the interpreter
	result, either \fBTcl_RestoreResult\fR or
	\fBTcl_DiscardResult\fR must be called to properly clean up the
	memory associated with the saved state.

	.SH KEYWORDS
	result, state, interp