#!/usr/bin/env lua5.1

local pcap = require"pcap"

arg.device = "any"

arg.snaplen = 0

arg.promisc = false

arg.filter = nil

arg.save = nil

arg.timeout = 1

for i,a in ipairs(arg) do

local s,e,k,v = a:find("^([^=]+)=(.*)$")

arg[k] = v

end

for k,v in pairs(arg) do

if type(k) == "string" then

print("arg", k, v)

end

end

cap = assert(pcap.open_live(arg.device, arg.snaplen, arg.promisc, arg.timeout))

print("cap", cap)

if arg.save then

out = assert(cap:dump_open(arg.save))

end

if arg.filter then

assert(cap:set_filter(arg.filter))

end

function loop(cap)

local n

n = function(cap)

local capdata, timestamp, wirelen = cap:next()

if capdata then

return capdata, timestamp, wirelen

end

local emsg = timestamp

if emsg == "closed" then

return nil

end

if emsg == "timeout" then

return n(cap)

end

assert(nil, timestamp)

end

return n, cap

end

for capdata, timestamp, wirelen in loop(cap) do

print("#", timestamp, wirelen, #capdata)

if out then

assert(out:dump(capdata, timestamp, wirelen))

end

end