#!/bin/sh

UA="Mozilla/5.0 (Windows NT 6.1; rv:31.0) Gecko/20100101 Firefox/31"
THREADS=2

hexdump -e '"%x\n"' /dev/urandom \
    | sed -E 's!(.{6}).*!https://gs.3g.cn/D/\1/w!' \
    | xargs -n1 -P$THREADS curl -vA "$UA" 2>&1 \
    | grep location: | grep -oP '(?<=\?u=)http[^&]+' \
    | sed 's,%2F,/,g;s,%3A,:,g' \
    | xargs -n1 -P$THREADS wget -U "$UA" -c