vicious/wifi.lua

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-- Licensed under the GNU General Public License v2
--  * (c) 2010, Adrian C. <anrxc@sysphere.org>
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-- {{{ Grab environment
local tonumber = tonumber
local io = { popen = io.popen }
local setmetatable = setmetatable
local string = {
    find = string.find,
    match = string.match
}
-- }}}


-- Wifi: provides wireless information for a requested interface
module("vicious.wifi")


-- {{{ Wireless widget type
local function worker(format, iface)
    -- Get data from iwconfig (where available)
    local f = io.popen("iwconfig " .. iface)
    local iw = f:read("*all")
    f:close()

    -- Default values
    local winfo = {
        ["{ssid}"] = "N/A",
        ["{mode}"] = "N/A",
        ["{chan}"] = "N/A",
        ["{rate}"] = 0,
        ["{link}"] = 0,
        ["{sign}"] = 0
    }

    -- Check if iwconfig wasn't found, can't be executed or the
    -- interface is not a wireless one
    if iw == nil or string.find(iw, "No such device") then
        return winfo
    end

    -- The output differs from system to system, some stats can
    -- be separated by =, and not all drivers report all stats
    winfo["{ssid}"] =  -- SSID can have almost anything in it
      string.match(iw, 'ESSID[=:]"([%w%p]+[%s]*[%w%p]*]*)"') or winfo["{ssid}"]
    winfo["{mode}"] =  -- Modes are simple, but also match the "-" in Ad-Hoc
      string.match(iw, "Mode[=:]([%w%-]*)") or winfo["{mode}"]
    winfo["{chan}"] =  -- Channels are plain digits
      tonumber(string.match(iw, "Channel[=:]([%d]+)") or winfo["{chan}"])
    winfo["{rate}"] =  -- Bitrate can start with a space, we don't want to display Mb/s
      tonumber(string.match(iw, "Bit Rate[=:]([%s]?[%d%.]*)") or winfo["{rate}"])
    winfo["{link}"] =  -- Link quality can contain a slash (32/70), match only the first number
      tonumber(string.match(iw, "Link Quality[=:]([%d]+)") or winfo["{link}"])
    winfo["{sign}"] =  -- Signal level can be a negative value, don't display decibel notation
      tonumber(string.match(iw, "Signal level[=:]([%-]?[%d]+)") or winfo["{sign}"])

    return winfo
end
-- }}}

setmetatable(_M, { __call = function(_, ...) return worker(...) end })