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Diffstat (limited to 'doc/proc.n')
| -rw-r--r-- | doc/proc.n | 194 |
1 files changed, 97 insertions, 97 deletions
@@ -1,97 +1,97 @@ -'\"
-'\" 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: proc.n,v 1.6 2007/10/29 01:42:19 dkf Exp $
-'\"
-.so man.macros
-.TH proc n "" Tcl "Tcl Built-In Commands"
-.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.
-Normally, \fIname\fR is unqualified
-(does not include the names of any containing namespaces),
-and the new procedure is created in the current namespace.
-If \fIname\fR includes any namespace qualifiers,
-the procedure is created in the specified namespace.
-\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 do not 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.
-Namespace variables can only be accessed by invoking
-the \fBvariable\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 does not 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 EXAMPLES
-This is a procedure that accepts arbitrarily many arguments and prints
-them out, one by one.
-.CS
-\fBproc\fR printArguments args {
- foreach arg $args {
- puts $arg
- }
-}
-.CE
-.PP
-This procedure is a bit like the \fBincr\fR command, except it
-multiplies the contents of the named variable by the value, which
-defaults to \fB2\fR:
-.CS
-\fBproc\fR mult {varName {multiplier 2}} {
- upvar 1 $varName var
- set var [expr {$var * $multiplier}]
-}
-.CE
-
-.SH "SEE ALSO"
-info(n), unknown(n)
-
-.SH KEYWORDS
-argument, procedure
+'\" +'\" 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: proc.n,v 1.7 2007/10/29 17:17:54 dgp Exp $ +'\" +.so man.macros +.TH proc n "" Tcl "Tcl Built-In Commands" +.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. +Normally, \fIname\fR is unqualified +(does not include the names of any containing namespaces), +and the new procedure is created in the current namespace. +If \fIname\fR includes any namespace qualifiers, +the procedure is created in the specified namespace. +\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 do not 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. +Namespace variables can only be accessed by invoking +the \fBvariable\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 does not 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 EXAMPLES +This is a procedure that accepts arbitrarily many arguments and prints +them out, one by one. +.CS +\fBproc\fR printArguments args { + foreach arg $args { + puts $arg + } +} +.CE +.PP +This procedure is a bit like the \fBincr\fR command, except it +multiplies the contents of the named variable by the value, which +defaults to \fB2\fR: +.CS +\fBproc\fR mult {varName {multiplier 2}} { + upvar 1 $varName var + set var [expr {$var * $multiplier}] +} +.CE + +.SH "SEE ALSO" +info(n), unknown(n) + +.SH KEYWORDS +argument, procedure |