man/mann/uplevel.n - toolchains/skids - Git at Google

 '\"
 '\" Copyright (c) 1993 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.
 '\"
 '\" RCS: @(#) $Id: uplevel.n,v 1.3 2000/09/07 14:27:52 poenitz 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.
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 '\" .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
 .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 !"\\$2"" .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 5.5c 11c
 .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 uplevel n "" Tcl "Tcl Built-In Commands"
 .BS
 '\" Note:  do not modify the .SH NAME line immediately below!
 .SH NAME
 uplevel \- Execute a script in a different stack frame
 .SH SYNOPSIS
 \fBuplevel \fR?\fIlevel\fR?\fI arg \fR?\fIarg ...\fR?
 .BE

 .SH DESCRIPTION
 .PP
 All of the \fIarg\fR arguments are concatenated as if they had
 been passed to \fBconcat\fR; the result is then evaluated in the
 variable context indicated by \fIlevel\fR.  \fBUplevel\fR returns
 the result of that evaluation.
 .PP
 If \fIlevel\fR is an integer then
 it gives a distance (up the procedure calling stack) to move before
 executing the command.  If \fIlevel\fR consists of \fB#\fR followed by
 a number then the number gives an absolute level number.  If \fIlevel\fR
 is omitted then it defaults to \fB1\fR.  \fILevel\fR cannot be
 defaulted if the first \fIcommand\fR argument starts with a digit or \fB#\fR.
 .PP
 For example, suppose that procedure \fBa\fR was invoked
 from top-level, and that it called \fBb\fR, and that \fBb\fR called \fBc\fR.
 Suppose that \fBc\fR invokes the \fBuplevel\fR command.  If \fIlevel\fR
 is \fB1\fR or \fB#2\fR  or omitted, then the command will be executed
 in the variable context of \fBb\fR.  If \fIlevel\fR is \fB2\fR or \fB#1\fR
 then the command will be executed in the variable context of \fBa\fR.
 If \fIlevel\fR is \fB3\fR or \fB#0\fR then the command will be executed
 at top-level (only global variables will be visible).
 .PP
 The \fBuplevel\fR command causes the invoking procedure to disappear
 from the procedure calling stack while the command is being executed.
 In the above example, suppose \fBc\fR invokes the command
 .CS
 \fBuplevel 1 {set x 43; d}\fR
 .CE
 where \fBd\fR is another Tcl procedure.  The \fBset\fR command will
 modify the variable \fBx\fR in \fBb\fR's context, and \fBd\fR will execute
 at level 3, as if called from \fBb\fR.  If it in turn executes
 the command
 .CS
 \fBuplevel {set x 42}\fR
 .CE
 then the \fBset\fR command will modify the same variable \fBx\fR in \fBb\fR's
 context:  the procedure \fBc\fR does not appear to be on the call stack
 when \fBd\fR is executing.  The command ``\fBinfo level\fR'' may
 be used to obtain the level of the current procedure.
 .PP
 \fBUplevel\fR makes it possible to implement new control
 constructs as Tcl procedures (for example, \fBuplevel\fR could
 be used to implement the \fBwhile\fR construct as a Tcl procedure).
 .PP
 \fBnamespace eval\fR is another way (besides procedure calls)
 that the Tcl naming context can change.
 It adds a call frame to the stack to represent the namespace context.
 This means each \fBnamespace eval\fR command
 counts as another call level for \fBuplevel\fR and \fBupvar\fR commands.
 For example, \fBinfo level 1\fR will return a list
 describing a command that is either
 the outermost procedure call or the outermost \fBnamespace eval\fR command.
 Also, \fBuplevel #0\fR evaluates a script
 at top-level in the outermost namespace (the global namespace).

 .SH "SEE ALSO"
 namespace(n), upvar(n)

 .SH KEYWORDS
 context, level, namespace, stack frame, variables
	'\"
	'\" Copyright (c) 1993 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.
	'\"
	'\" RCS: @(#) $Id: uplevel.n,v 1.3 2000/09/07 14:27:52 poenitz 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
	.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 !"\\$2"" .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 5.5c 11c
	.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 uplevel n "" Tcl "Tcl Built-In Commands"
	.BS
	'\" Note: do not modify the .SH NAME line immediately below!
	.SH NAME
	uplevel \- Execute a script in a different stack frame
	.SH SYNOPSIS
	\fBuplevel \fR?\fIlevel\fR?\fI arg \fR?\fIarg ...\fR?
	.BE

	.SH DESCRIPTION
	.PP
	All of the \fIarg\fR arguments are concatenated as if they had
	been passed to \fBconcat\fR; the result is then evaluated in the
	variable context indicated by \fIlevel\fR. \fBUplevel\fR returns
	the result of that evaluation.
	.PP
	If \fIlevel\fR is an integer then
	it gives a distance (up the procedure calling stack) to move before
	executing the command. If \fIlevel\fR consists of \fB#\fR followed by
	a number then the number gives an absolute level number. If \fIlevel\fR
	is omitted then it defaults to \fB1\fR. \fILevel\fR cannot be
	defaulted if the first \fIcommand\fR argument starts with a digit or \fB#\fR.
	.PP
	For example, suppose that procedure \fBa\fR was invoked
	from top-level, and that it called \fBb\fR, and that \fBb\fR called \fBc\fR.
	Suppose that \fBc\fR invokes the \fBuplevel\fR command. If \fIlevel\fR
	is \fB1\fR or \fB#2\fR or omitted, then the command will be executed
	in the variable context of \fBb\fR. If \fIlevel\fR is \fB2\fR or \fB#1\fR
	then the command will be executed in the variable context of \fBa\fR.
	If \fIlevel\fR is \fB3\fR or \fB#0\fR then the command will be executed
	at top-level (only global variables will be visible).
	.PP
	The \fBuplevel\fR command causes the invoking procedure to disappear
	from the procedure calling stack while the command is being executed.
	In the above example, suppose \fBc\fR invokes the command
	.CS
	\fBuplevel 1 {set x 43; d}\fR
	.CE
	where \fBd\fR is another Tcl procedure. The \fBset\fR command will
	modify the variable \fBx\fR in \fBb\fR's context, and \fBd\fR will execute
	at level 3, as if called from \fBb\fR. If it in turn executes
	the command
	.CS
	\fBuplevel {set x 42}\fR
	.CE
	then the \fBset\fR command will modify the same variable \fBx\fR in \fBb\fR's
	context: the procedure \fBc\fR does not appear to be on the call stack
	when \fBd\fR is executing. The command ``\fBinfo level\fR'' may
	be used to obtain the level of the current procedure.
	.PP
	\fBUplevel\fR makes it possible to implement new control
	constructs as Tcl procedures (for example, \fBuplevel\fR could
	be used to implement the \fBwhile\fR construct as a Tcl procedure).
	.PP
	\fBnamespace eval\fR is another way (besides procedure calls)
	that the Tcl naming context can change.
	It adds a call frame to the stack to represent the namespace context.
	This means each \fBnamespace eval\fR command
	counts as another call level for \fBuplevel\fR and \fBupvar\fR commands.
	For example, \fBinfo level 1\fR will return a list
	describing a command that is either
	the outermost procedure call or the outermost \fBnamespace eval\fR command.
	Also, \fBuplevel #0\fR evaluates a script
	at top-level in the outermost namespace (the global namespace).

	.SH "SEE ALSO"
	namespace(n), upvar(n)

	.SH KEYWORDS
	context, level, namespace, stack frame, variables