code: 9ferno

ref: 0ee70192a6748cb9adf572ac584ca7dd417cf1ef
dir: /man/9/variable/

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.TH VARIABLE 9
.SH NAME
variable \- interrogate a button variable
.SH SYNOPSIS
\f5variable \fIvar\fR ?\fIvalue\fR?
.SH DESCRIPTION
.B Variable
queries or sets the value of a Tk radiobutton, checkbutton or choicebutton variable.
An error diagnostic will be returned if
the variable is of the wrong type (if for instance
it is the name of a named channel).
.PP
If \fIvalue\fR is given, the value of the variable is set
to that value, and any associated buttons
will subsequently reflect this in their appearance.
Omitting the \fIvalue\fR argument returns the current value of the variable.
.PP
The special variable
.B lasterror
holds the text of the last Tk error encountered.
It resets when queried.
.SH SEE ALSO
.IR checkbutton (9),
.IR choicebutton (9),
.IR radiobutton (9)