#!/bin/sh
#\
exec wish "$0" "$@"

proc entFmt {format buf c ins inv} {
	puts "entFmt: $format $buf $c $ins $inv"
	return 1
	
	set r 1
	set bmax [expr [string length $buf]-1]
	if {$ins} {
	### insert a char
		set f [string index $format $bmax]
		for {set i $bmax} {$i < 1000} {incr i} {
			upvar $inv new
			set new $buf 
			if {[string first $f "zZ9aAxX"] > 0} {
				set new [string range $buf 0 end-1]$f
				set r 0
			}
		} 
	} else {
	### delete a char
	}
    puts "return: $r"
	return $r
}

### exemplo de uso

label .l4 -text "A phone number:\
            \n(99) 9999-9999"
entry .e4 -vcmd {entFmt {(99) 9999-9999} %P %S %d Ve4} \
	-validate key -invcmd {
        %W delete 0 end
        %W insert 0 $Ve4
        after idle %W configure -validate key
	}

pack .l4 .e4