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diff --git a/tcl8.6/doc/variable.n b/tcl8.6/doc/variable.n new file mode 100644 index 0000000..8228859 --- /dev/null +++ b/tcl8.6/doc/variable.n @@ -0,0 +1,105 @@ +'\" +'\" Copyright (c) 1993-1997 Bell Labs Innovations for Lucent Technologies +'\" Copyright (c) 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. +'\" +.TH variable n 8.0 Tcl "Tcl Built-In Commands" +.so man.macros +.BS +'\" Note: do not modify the .SH NAME line immediately below! +.SH NAME +variable \- create and initialize a namespace variable +.SH SYNOPSIS +\fBvariable \fR\fIname\fR +.sp +\fBvariable \fR?\fIname value...\fR? +.BE +.SH DESCRIPTION +.PP +This command is normally used within a +\fBnamespace eval\fR command to create one or more variables +within a namespace. +Each variable \fIname\fR is initialized with \fIvalue\fR. +The \fIvalue\fR for the last variable is optional. +.PP +If a variable \fIname\fR does not exist, it is created. +In this case, if \fIvalue\fR is specified, +it is assigned to the newly created variable. +If no \fIvalue\fR is specified, the new variable is left undefined. +If the variable already exists, +it is set to \fIvalue\fR if \fIvalue\fR is specified +or left unchanged if no \fIvalue\fR is given. +Normally, \fIname\fR is unqualified +(does not include the names of any containing namespaces), +and the variable is created in the current namespace. +If \fIname\fR includes any namespace qualifiers, +the variable is created in the specified namespace. If the variable +is not defined, it will be visible to the \fBnamespace which\fR +command, but not to the \fBinfo exists\fR command. +.PP +If the \fBvariable\fR command is executed inside a Tcl procedure, +it creates local variables +linked to the corresponding namespace variables (and therefore these +variables are listed by \fBinfo vars\fR.) +In this way the \fBvariable\fR command resembles the \fBglobal\fR command, +although the \fBglobal\fR command +resolves variable names with respect to the global namespace instead +of the current namespace of the procedure. +If any \fIvalue\fRs are given, +they are used to modify the values of the associated namespace variables. +If a namespace variable does not exist, +it is created and optionally initialized. +.PP +A \fIname\fR argument cannot reference an element within an array. +Instead, \fIname\fR should reference the entire array, +and the initialization \fIvalue\fR should be left off. +After the variable has been declared, +elements within the array can be set using ordinary +\fBset\fR or \fBarray\fR commands. +.SH EXAMPLES +.PP +Create a variable in a namespace: +.PP +.CS +namespace eval foo { + \fBvariable\fR bar 12345 +} +.CE +.PP +Create an array in a namespace: +.PP +.CS +namespace eval someNS { + \fBvariable\fR someAry + array set someAry { + someName someValue + otherName otherValue + } +} +.CE +.PP +Access variables in namespaces from a procedure: +.PP +.CS +namespace eval foo { + proc spong {} { + # Variable in this namespace + \fBvariable\fR bar + puts "bar is $bar" + + # Variable in another namespace + \fBvariable\fR ::someNS::someAry + parray someAry + } +} +.CE +.SH "SEE ALSO" +global(n), namespace(n), upvar(n) +.SH KEYWORDS +global, namespace, procedure, variable +.\" Local variables: +.\" mode: nroff +.\" fill-column: 78 +.\" End: |