home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
The Fatted Calf
/
The Fatted Calf.iso
/
Demos
/
ByCompany
/
TipTop_Software
/
TipTop
/
Supplement
/
man
/
tcl
/
proc.n
< prev
next >
Wrap
Text File
|
1994-05-08
|
8KB
|
262 lines
'\"
'\" Copyright (c) 1993 The Regents of the University of California.
'\" All rights reserved.
'\"
'\" Permission is hereby granted, without written agreement and without
'\" license or royalty fees, to use, copy, modify, and distribute this
'\" documentation for any purpose, provided that the above copyright
'\" notice and the following two paragraphs appear in all copies.
'\"
'\" IN NO EVENT SHALL THE UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY
'\" FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
'\" ARISING OUT OF THE USE OF THIS DOCUMENTATION, EVEN IF THE UNIVERSITY OF
'\" CALIFORNIA HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
'\"
'\" THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY WARRANTIES,
'\" INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
'\" AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
'\" ON AN "AS IS" BASIS, AND THE UNIVERSITY OF CALIFORNIA HAS NO OBLIGATION TO
'\" PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
'\"
'\" $Header: /user6/ouster/tcl/man/RCS/proc.n,v 1.1 93/05/10 17:10:18 ouster Exp $ SPRITE (Berkeley)
'\"
.\" The definitions below are for supplemental macros used in Tcl/Tk
.\" manual entries.
.\"
.\" .HS name section [date [version]]
.\" Replacement for .TH in other man pages. See below for valid
.\" section names.
.\"
.\" .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.
.\"
.\" .VS
.\" Begin vertical sidebar, for use in marking newly-changed parts
.\" of man pages.
.\"
.\" .VE
.\" End of vertical sidebar.
.\"
.\" .DS
.\" Begin an indented unfilled display.
.\"
.\" .DE
.\" End of indented unfilled display.
.\"
'\" # Heading for Tcl/Tk man pages
.de HS
.ds ^3 \\0
.if !"\\$3"" .ds ^3 \\$3
.if '\\$2'cmds' .TH \\$1 1 \\*(^3 \\$4
.if '\\$2'lib' .TH \\$1 3 \\*(^3 \\$4
.if '\\$2'tcl' .TH \\$1 n \\*(^3 Tcl "Tcl Built-In Commands"
.if '\\$2'tk' .TH \\$1 n \\*(^3 Tk "Tk Commands"
.if '\\$2'tclc' .TH \\$1 3 \\*(^3 Tcl "Tcl Library Procedures"
.if '\\$2'tkc' .TH \\$1 3 \\*(^3 Tk "Tk Library Procedures"
.if '\\$2'tclcmds' .TH \\$1 1 \\*(^3 Tk "Tcl Applications"
.if '\\$2'tkcmds' .TH \\$1 1 \\*(^3 Tk "Tk Applications"
.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
..
'\" # 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
.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 .5
..
.HS proc tcl
.BS
'\" Note: do not modify the .SH NAME line immediately below!
.SH NAME
proc \- Create a Tcl procedure
.SH SYNOPSIS
\fBproc \fIname args body\fR
.BE
.SH DESCRIPTION
.PP
The \fBproc\fR command creates a new Tcl procedure named
\fIname\fR, replacing
any existing command or procedure there may have been by that name.
Whenever the new command is invoked, the contents of \fIbody\fR will
be executed by the Tcl interpreter.
\fIArgs\fR specifies the formal arguments to the
procedure. It consists of a list, possibly empty, each of whose
elements specifies
one argument. Each argument specifier is also a list with either
one or two fields. If there is only a single field in the specifier
then it is the name of the argument; if there are two fields, then
the first is the argument name and the second is its default value.
.PP
When \fIname\fR is invoked a local variable
will be created for each of the formal arguments to the procedure; its
value will be the value of corresponding argument in the invoking command
or the argument's default value.
Arguments with default values need not be
specified in a procedure invocation. However, there must be enough
actual arguments for all the
formal arguments that don't have defaults, and there must not be any extra
actual arguments. There is one special case to permit procedures with
variable numbers of arguments. If the last formal argument has the name
\fBargs\fR, then a call to the procedure may contain more actual arguments
than the procedure has formals. In this case, all of the actual arguments
starting at the one that would be assigned to \fBargs\fR are combined into
a list (as if the \fBlist\fR command had been used); this combined value
is assigned to the local variable \fBargs\fR.
.PP
When \fIbody\fR is being executed, variable names normally refer to
local variables, which are created automatically when referenced and
deleted when the procedure returns. One local variable is automatically
created for each of the procedure's arguments.
Global variables can only be accessed by invoking
the \fBglobal\fR command or the \fBupvar\fR command.
.PP
The \fBproc\fR command returns an empty string. When a procedure is
invoked, the procedure's return value is the value specified in a
\fBreturn\fR command. If the procedure doesn't execute an explicit
\fBreturn\fR, then its return value is the value of the last command
executed in the procedure's body.
If an error occurs while executing the procedure
body, then the procedure-as-a-whole will return that same error.
.SH KEYWORDS
argument, procedure