2024-05-27 16:13:40 +02:00
|
|
|
'\"
|
|
|
|
|
'\" Copyright (c) 1993 The Regents of the University of California.
|
2024-05-27 16:40:40 +02:00
|
|
|
'\" Copyright (c) 1994-1996 Sun Microsystems, Inc.
|
2024-05-27 16:13:40 +02:00
|
|
|
'\"
|
2024-05-27 16:40:40 +02:00
|
|
|
'\" See the file "license.terms" for information on usage and redistribution
|
|
|
|
|
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
|
2024-05-27 16:13:40 +02:00
|
|
|
'\"
|
2024-05-27 16:40:40 +02:00
|
|
|
'\" SCCS: @(#) proc.n 1.5 96/03/25 20:21:12
|
2024-05-27 16:13:40 +02:00
|
|
|
'\"
|
|
|
|
|
.so man.macros
|
2024-05-27 16:40:40 +02:00
|
|
|
.TH proc n "" Tcl "Tcl Built-In Commands"
|
2024-05-27 16:13:40 +02:00
|
|
|
.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
|
