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

 '\"
 '\" Copyright (c) 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.
 '\"
 '\" RCS: @(#) $Id: unknown.n,v 1.4 2001/06/27 21:00:45 hobbs 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 unknown n "" Tcl "Tcl Built-In Commands"
 .BS
 '\" Note:  do not modify the .SH NAME line immediately below!
 .SH NAME
 unknown \- Handle attempts to use non-existent commands
 .SH SYNOPSIS
 \fBunknown \fIcmdName \fR?\fIarg arg ...\fR?
 .BE

 .SH DESCRIPTION
 .PP
 This command is invoked by the Tcl interpreter whenever a script
 tries to invoke a command that doesn't exist.  The default implementation
 of \fBunknown\fR is a library procedure defined when Tcl initializes an
 interpreter.  You can override the default \fBunknown\fR to change its
 functionality.  Note that there is no default implementation of
 \fBunknown\fR in a safe interpreter.
 .PP
 If the Tcl interpreter encounters a command name for which there
 is not a defined command, then Tcl checks for the existence of
 a command named \fBunknown\fR.
 If there is no such command, then the interpreter returns an
 error.
 If the \fBunknown\fR command exists, then it is invoked with
 arguments consisting of the fully-substituted name and arguments
 for the original non-existent command.
 The \fBunknown\fR command typically does things like searching
 through library directories for a command procedure with the name
 \fIcmdName\fR, or expanding abbreviated command names to full-length,
 or automatically executing unknown commands as sub-processes.
 In some cases (such as expanding abbreviations) \fBunknown\fR will
 change the original command slightly and then (re-)execute it.
 The result of the \fBunknown\fR command is used as the result for
 the original non-existent command.
 .PP
 The default implementation of \fBunknown\fR behaves as follows.
 It first calls the \fBauto_load\fR library procedure to load the command.
 If this succeeds, then it executes the original command with its
 original arguments.
 If the auto-load fails then \fBunknown\fR calls \fBauto_execok\fR
 to see if there is an executable file by the name \fIcmd\fR.
 If so, it invokes the Tcl \fBexec\fR command
 with \fIcmd\fR and all the \fIargs\fR as arguments.
 If \fIcmd\fR can't be auto-executed, \fBunknown\fR checks to
 see if the command was invoked at top-level and outside of any
 script.  If so, then \fBunknown\fR takes two additional steps.
 First, it sees if \fIcmd\fR has one of the following three forms:
 \fB!!\fR, \fB!\fIevent\fR, or \fB^\fIold\fB^\fInew\fR?\fB^\fR?.
 If so, then \fBunknown\fR carries out history substitution
 in the same way that \fBcsh\fR would for these constructs.
 Finally, \fBunknown\fR checks to see if \fIcmd\fR is
 a unique abbreviation for an existing Tcl command.
 If so, it expands the command name and executes the command with
 the original arguments.
 If none of the above efforts has been able to execute
 the command, \fBunknown\fR generates an error return.
 If the global variable \fBauto_noload\fR is defined, then the auto-load
 step is skipped.
 If the global variable \fBauto_noexec\fR is defined then the
 auto-exec step is skipped.
 Under normal circumstances the return value from \fBunknown\fR
 is the return value from the command that was eventually
 executed.

 .SH "SEE ALSO"
 info(n), proc(n), interp(n), library(n)

 .SH KEYWORDS
 error, non-existent command
	'\"
	'\" Copyright (c) 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.
	'\"
	'\" RCS: @(#) $Id: unknown.n,v 1.4 2001/06/27 21:00:45 hobbs 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 unknown n "" Tcl "Tcl Built-In Commands"
	.BS
	'\" Note: do not modify the .SH NAME line immediately below!
	.SH NAME
	unknown \- Handle attempts to use non-existent commands
	.SH SYNOPSIS
	\fBunknown \fIcmdName \fR?\fIarg arg ...\fR?
	.BE

	.SH DESCRIPTION
	.PP
	This command is invoked by the Tcl interpreter whenever a script
	tries to invoke a command that doesn't exist. The default implementation
	of \fBunknown\fR is a library procedure defined when Tcl initializes an
	interpreter. You can override the default \fBunknown\fR to change its
	functionality. Note that there is no default implementation of
	\fBunknown\fR in a safe interpreter.
	.PP
	If the Tcl interpreter encounters a command name for which there
	is not a defined command, then Tcl checks for the existence of
	a command named \fBunknown\fR.
	If there is no such command, then the interpreter returns an
	error.
	If the \fBunknown\fR command exists, then it is invoked with
	arguments consisting of the fully-substituted name and arguments
	for the original non-existent command.
	The \fBunknown\fR command typically does things like searching
	through library directories for a command procedure with the name
	\fIcmdName\fR, or expanding abbreviated command names to full-length,
	or automatically executing unknown commands as sub-processes.
	In some cases (such as expanding abbreviations) \fBunknown\fR will
	change the original command slightly and then (re-)execute it.
	The result of the \fBunknown\fR command is used as the result for
	the original non-existent command.
	.PP
	The default implementation of \fBunknown\fR behaves as follows.
	It first calls the \fBauto_load\fR library procedure to load the command.
	If this succeeds, then it executes the original command with its
	original arguments.
	If the auto-load fails then \fBunknown\fR calls \fBauto_execok\fR
	to see if there is an executable file by the name \fIcmd\fR.
	If so, it invokes the Tcl \fBexec\fR command
	with \fIcmd\fR and all the \fIargs\fR as arguments.
	If \fIcmd\fR can't be auto-executed, \fBunknown\fR checks to
	see if the command was invoked at top-level and outside of any
	script. If so, then \fBunknown\fR takes two additional steps.
	First, it sees if \fIcmd\fR has one of the following three forms:
	\fB!!\fR, \fB!\fIevent\fR, or \fB^\fIold\fB^\fInew\fR?\fB^\fR?.
	If so, then \fBunknown\fR carries out history substitution
	in the same way that \fBcsh\fR would for these constructs.
	Finally, \fBunknown\fR checks to see if \fIcmd\fR is
	a unique abbreviation for an existing Tcl command.
	If so, it expands the command name and executes the command with
	the original arguments.
	If none of the above efforts has been able to execute
	the command, \fBunknown\fR generates an error return.
	If the global variable \fBauto_noload\fR is defined, then the auto-load
	step is skipped.
	If the global variable \fBauto_noexec\fR is defined then the
	auto-exec step is skipped.
	Under normal circumstances the return value from \fBunknown\fR
	is the return value from the command that was eventually
	executed.

	.SH "SEE ALSO"
	info(n), proc(n), interp(n), library(n)

	.SH KEYWORDS
	error, non-existent command