-- read from nginx var config
local magick = ngx.var.magick
ngx.log(ngx.ERR, 'var', magick)
-- or use which command to get
if not magick then
    local exec = io.popen("which magick")
    local tmp = exec:read("*a")
    magick = string.gsub(tmp, "%s+", "")
    exec:close()
end
if not magick then
    ngx.status = 500
    ngx.say("image magick not found.")
    return
end

ngx.say(magick)


--local origin = {
--    "/Users/moicen/Music/alchemy/Song-of-joy.png",
--    "/Users/moicen/Music/alchemy/You-and-me.png"
--}
--origin = table.concat(origin, " ")
--ngx.log(ngx.ERR, origin)
--local file = io.popen("/usr/local/bin/magick convert -append " .. origin .. " /tmp/combined.jpeg" )
--local output = file:read("*all")
--file:close()
--ngx.say(output)