Pure Bash Web Server(github.com)

    #!/bin/bash
    cd songs
    if [[ ! -p q ]]; then
        mkfifo q
    fi

    (while true; do echo "playing" | nc -l 10000 | head -n 1 | cut -f 2 -d " " | cut -b 2- | grep -E "^[a-zA-Z0-9/:.?=-]{1,}$" > q; done) &

    while true; do
        if read a <q; then
        echo $a;
        fn=$(youtube-dl -f m4a --id --get-filename $a);
        youtube-dl -f m4a --id $a
        echo $fn
        mplayer $fn
        fi
    done

  n=$(gzip -9 < /etc/passwd)
  gzip -9 < /etc/passwd | sum
  echo "$n" | sum

        tee /tmp/server > /dev/null <<'EOF'
        #!/bin/bash
        set -euo pipefail
        SERVE="$1"
        TYPE="$2"
        read -a WORDS
        if [ "${#WORDS[@]}" != 3 ] || [ "${WORDS[0]}" != "GET" ]; then
          echo -ne "HTTP/1.1 400 Bad request\r\n\r\n"; exit 0
        fi
        # Subfolders are not supported for security reasons as this avoids having to deal with ../../ attacks
        FILE="${SERVE}/$(basename -- "${WORDS[1]}")"
        if [ -d "${FILE}" ] || [ ! -e "${FILE}" ]; then
          echo -ne "HTTP/1.1 404 Not found\r\n\r\n" ; exit 0
        fi
        echo -ne "HTTP/1.1 200 OK\r\n"
        echo -ne "Content-Type: ${TYPE};\r\n"
        LEN=$(stat -L --printf='%s\n' "${FILE}")
        echo -ne "Content-Length: ${LEN}\r\n"
        echo -ne "\r\n"
        cat "${FILE}"
        EOF
        chmod +x /tmp/server
        # switch from "text/plain" to "application/octet-stream" for file downloads
        socat TCP-LISTEN:8000,reuseaddr,fork SYSTEM:'/tmp/server /tmp/ text-plain'