#!tcl

#
# cfgns - extract all DNS Servers from winipcfg.out
#

if {$argc != 0} {
    error "usage: cfgns"
}

set f [open "winipcfg.out" r]

set dns 0.0.0.0
set found 0

#
# find DNS Servers line and get the first IP address
#

set pat "DNS Servers" 
while {[gets $f line] >= 0} {
    if [regexp $pat $line] {
        set l [expr [llength $line]-1]
        set dns [lindex $line $l]
        if {$dns == ":"} {set dns "0.0.0.0"}
        break
    }
}

#
# create dns.tmp
#

set out [open "dns.tmp" w]

puts -nonewline $out $dns

#
# get next entries
#

set pat ":"
while {[gets $f line] >= 0} {
    set l [expr [llength $line]-1]
    set dns [lindex $line $l]
    if [regexp $pat $line] {break}
    puts -nonewline $out $dns
}
close $out
close $f
