dubiouscript · August 27, 2021 18:52
diff --git a/bashttpd b/bashttpd
 #!/usr/bin/env bash
 #
 ###
 # https://gist.github.com/dubiouscript/e90a515b6ee2b5fe8988b945b0cdb418#this
 #
 # https://raw.githubusercontent.com/TooTallNate/bashttpd/master/bashttpd#origin
 #
 # https://raw.githubusercontent.com/TooTallNate/bashttpd/79582483264acad15b49e4b911f17f7bda753f43/bashttpd
 ###
 #
 # https://github.com/for-GET/literate-http
 # https://learnxinyminutes.com/docs/bash/
 # https://github.com/pkrumins/bash-redirections-cheat-sheet
 # http://www.binaryphile.com/bash/2018/07/26/approach-bash-like-a-developer-part-1-intro.html
 # https://learnxinyminutes.com/docs/html/
 # https://developer.mozilla.org/en-US/docs/Web/HTML/Element
 # https://html.spec.whatwg.org/
 # https://learnxinyminutes.com/docs/javascript/
 # https://learnxinyminutes.com/docs/json/
 # 
 # https://github.com/for-GET/know-your-http-well
 # https://github.com/for-GET/know-your-http-well/blob/master/json/methods.json
 # https://github.com/for-GET/know-your-http-well/blob/master/json/headers.json
 # 
 # https://github.com/topics/http
 # https://github.com/topics/http?l=shell 
 #
 ##

 #
 # A simple, configurable HTTP server written in bash.
 #
 # See LICENSE for licensing information.
 #
 # Original author: Avleen Vig, 2012
 # Reworked by:     Josh Cartwright, 2012
 # Reworked by:     Nathan Rajlich, 2018
 #  +gzip ,ect:             ~dscr

 # If running as `root`, then downgrade to `nobody` first
 if [ "$EUID" -eq 0 ]; then
  exec sudo -u nobody "$0" "$@"
 fi

 conf="${BASHTTPD_CONFIG-bashttpd.conf}"

 [ -r "${conf}" ] || {
   cat > "${conf}" <<'EOF'
 #
 # bashttpd.conf - configuration for bashttpd
 #
 # The behavior of bashttpd is dictated by the evaluation
 # of rules specified in this configuration file.  Each rule
 # is evaluated until one is matched.  If no rule is matched,
 # bashttpd will serve a 500 Internal Server Error.
 #
 # The format of the rules are:
 #    on_uri_match REGEX command [args]
 #    unconditionally command [args]
 #
 # on_uri_match:
 #   On an incoming request, the URI is checked against the specified
 #   (bash-supported extended) regular expression, and if encounters a match the
 #   specified command is executed with the specified arguments.
 #
 #   For additional flexibility, on_uri_match will also pass the results of the
 #   regular expression match, ${BASH_REMATCH[@]} as additional arguments to the
 #   command.
 #
 # unconditionally:
 #   Always serve via the specified command.  Useful for catchall rules.
 #
 # The following commands are available for use:
 #
 #   serve_file FILE
 #     Statically serves a single file.
 #
 #   serve_dir_with_tree DIRECTORY
 #     Statically serves the specified directory using 'tree'.  It must be
 #     installed and in the PATH.
 #
 #   serve_dir_with_ls DIRECTORY
 #     Statically serves the specified directory using 'ls -al'.
 #
 #   serve_dir  DIRECTORY
 #     Statically serves a single directory listing.  Will use 'tree' if it is
 #     installed and in the PATH, otherwise, 'ls -al'
 #
 #   serve_dir_or_file_from DIRECTORY
 #     Serves either a directory listing (using serve_dir) or a file (using
 #     serve_file).  Constructs local path by appending the specified root
 #     directory, and the URI portion of the client request.
 #
 #   serve_static_string STRING
 #     Serves the specified static string with Content-Type text/plain.
 #
 # Examples of rules:
 #
 # on_uri_match '^/issue$' serve_file "/etc/issue"
 #
 #   When a client's requested URI matches the string '/issue', serve them the
 #   contents of /etc/issue
 #
 # on_uri_match 'root' serve_dir /
 #
 #   When a client's requested URI has the word 'root' in it, serve up
 #   a directory listing of /
 #
 # DOCROOT=/var/www/html
 # on_uri_match '/(.*)' serve_dir_or_file_from "$DOCROOT"
 #   When any URI request is made, attempt to serve a directory listing
 #   or file content based on the request URI, by mapping URI's to local
 #   paths relative to the specified "$DOCROOT"
 #

 #
 #
 match_between() { sed -n '/'"$1"'/,/'"$2"'/p'; }
 #####
 html_Page() { head="$1"; body="$2"; serve_static_string "<html><head> $head </head><body> $body </body></html>"  "text/html" ; }
 html_link() { while read link text ; do [ -z "$link" ] || echo '<a href='"$link>${text:-$link}"'</a></br>' ; done ; }
 ##########

 # unconditionally serve_static_string 'Hello, world!  You can configure bashttpd by modifying bashttpd.conf.'


 ## http://humanstxt.org/
 ##
 humans() {  serve_static_string "$(cat $0 | match_between "^# Original author" "^$" | head -n-1 )"  ; }
 #
 on_uri_match  '^/humans.txt$' humans

 ##
 svr_self() {  serve_static_string "$(cat $0)" ; }
 #
 on_uri_match  '^/bashttpd$' svr_self
 
 ##
 svr_cfg() {   serve_static_string  "$( cat "${conf}" )" ; } 
 #
 on_uri_match  '^/bashttpd.conf$' svr_cfg 

 ###
  strip_comments()  { sed '/^[[:blank:]]*#/d;s/#.*//' ; }
  svr_lst_routes()   { cat "${conf}" | strip_comments | grep -e 'on_ur''i_match' | awk '{print $2}' | sed -e "s/^'\^//g" -e "s/\$'$//g" -e "s/\*'$//g" -e "s/'$//g" ; }

  default_route() { mod_cfg='Hello, world!  You can configure bashttpd by modifying '"${conf}.";
                    page_head="<title> Slash Bin Slash Bash </title>";
                    page_body="$( svr_lst_routes | sort | uniq | html_link) </br> $mod_cfg</hr>";
                    html_Page "$page_head" "$page_body";
  }
  
   ## 
 #
 on_uri_match  '^/$' default_route

 # More about commands:
 #
 # It is possible to somewhat easily write your own commands.  An example
 # may help.  The following example will serve "Hello, $x!" whenever
 # a client sends a request with the URI /say_hello_to/$x:
 #
 # serve_hello() {
 #    set_response_header "Content-Type" "text/plain"
 #    echo "Hello, $2!"
 # }
 # on_uri_match '^/say_hello_to/(.*)$' serve_hello
 #
 # Like mentioned before, the contents of ${BASH_REMATCH[@]} are passed
 # to your command, so its possible to use regular expression groups
 # to pull out info.
 #
 # With this example, when the requested URI is /say_hello_to/Josh, serve_hello
 # is invoked with the arguments '/say_hello_to/Josh' 'Josh',
 # (${BASH_REMATCH[0]} is always the full match)
 EOF
   echo "Created bashttpd.conf using defaults."
   echo "Please review it/configure before running bashttpd again."
   exit 1
 }

 recv() { echo "<" "$@" >&2; }
 send() { echo ">" "$@" >&2;
         printf "%s\r\n" "$*"; }

 read_bytes() {
  LANG=C IFS= read -r -d '' -n "$1" char
  printf "%s" "${char}"
 }

 DATE=$(date +"%a, %d %b %Y %H:%M:%S %Z")
 declare -a RESPONSE_HEADERS=(
      "Date: $DATE"
   "Expires: $DATE"
    "Server: Slash Bin Slash Bash"
 )

 add_response_header() {
   RESPONSE_HEADERS+=("$1: $2")
 }

 _add_response_header() {
   RESPONSE_HEADERS+=("$1")
 }

 # https://github.com/for-GET/know-your-http-well/blob/master/json/status-codes.json
 declare -a HTTP_RESPONSE=(
  [100]="Continue"
  [101]="Switching Protocols"
  [102]="Processing"
  [103]="Early Hints"
  [200]="OK"
  [201]="Created"
  [202]="Accepted"
  [203]="Non-Authoritative Information"
  [204]="No Content"
  [205]="Reset Content"
  [206]="Partial Content"
  [207]="Multi-Status"
  [208]="Already Reported"
  [226]="IM Used"
  [300]="Multiple Choices"
  [301]="Moved Permanently"
  [302]="Found"
  [303]="See Other"
  [304]="Not Modified"
  [305]="Use Proxy"
  [307]="Temporary Redirect"
  [308]="Permanent Redirect"
  [400]="Bad Request"
  [401]="Unauthorized"
  [402]="Payment Required"
  [403]="Forbidden"
  [404]="Not Found"
  [405]="Method Not Allowed"
  [406]="Not Acceptable"
  [407]="Proxy Authentication Required"
  [408]="Request Timeout"
  [409]="Conflict"
  [410]="Gone"
  [411]="Length Required"
  [412]="Precondition Failed"
  [413]="Payload Too Large"
  [414]="URI Too Long"
  [415]="Unsupported Media Type"
  [416]="Range Not Satisfiable"
  [417]="Expectation Failed"
  [418]="I'm a teapot"
  [421]="Misdirected Request"
  [422]="Unprocessable Entity"
  [423]="Locked"
  [424]="Failed Dependency"
  [425]="Unordered Collection"
  [426]="Upgrade Required"
  [428]="Precondition Required"
  [429]="Too Many Requests"
  [431]="Request Header Fields Too Large"
  [451]="Unavailable For Legal Reasons"
  [500]="Internal Server Error"
  [501]="Not Implemented"
  [502]="Bad Gateway"
  [503]="Service Unavailable"
  [504]="Gateway Timeout"
  [505]="HTTP Version Not Supported"
  [506]="Variant Also Negotiates"
  [507]="Insufficient Storage"
  [508]="Loop Detected"
  [509]="Bandwidth Limit Exceeded"
  [510]="Not Extended"
  [511]="Network Authentication Required"
 )

 send_response_header() {
   local code=$1
   send "HTTP/1.0 ${code} ${HTTP_RESPONSE[${code}]}"
   for i in "${RESPONSE_HEADERS[@]}"; do
      send "$i"
   done
   send
 }

 _fail_with() {
   send_response_header "$1"
   echo "$1 ${HTTP_RESPONSE[$1]}"
   exit 1
 }

 # Request-Line HTTP RFC 2616 $5.1
 IFS='' read -r line || _fail_with 400

 # strip trailing CR if it exists
 line=${line%%$'\r'}
 recv "$line"

 read -r REQUEST_METHOD REQUEST_URI REQUEST_HTTP_VERSION <<<"$line"

 [ -n "$REQUEST_METHOD" ] && \
 [ -n "$REQUEST_URI" ] && \
 [ -n "$REQUEST_HTTP_VERSION" ] \
   || _fail_with 400

 REQUEST_PATH="${REQUEST_URI%%\?*}"
 QUERY_STRING="${REQUEST_URI#*\?}"

 declare -a REQUEST_HEADERS

 while IFS='' read -r line; do
   line=${line%%$'\r'}
   recv "$line"

   # If we've reached the end of the headers, break.
   [ -z "$line" ] && break

   REQUEST_HEADERS+=("$line")
 done

 CONTROL_SEQUENCE=$'\1'

 flush_response() {
  # Wait for response code and header "events" from stdin
  local code=200
  local buf
  while true; do
    local buf="$(read_bytes "${#CONTROL_SEQUENCE}")"
    #recv "buf: $(printf "%x " "'${buf}") ${#buf}"
    if [ "${buf}" = "${CONTROL_SEQUENCE}" ]; then
      IFS='' read -r line
      line=${line%%$'\r'}
      #recv "line: ${line}"
      local cmd="${line:0:1}"
      local data="${line:1}"
      case "${cmd}" in
        C) code="${data}";;
        H) _add_response_header "${data}";;
      esac
    else
      break
    fi
  done
  send_response_header "${code}"
  printf "%s" "${buf}"
  cat
 }

 # Set the response status code.
 # MUST be called *before* any output is generated by your script.
 set_response_code() {
  echo "${CONTROL_SEQUENCE}C$1"
 }

 # Sets a response header.
 # MUST be called *before* any output is generated by your script.
 set_response_header() {
  local header="$1"
  shift
  if [ $# -ne 0 ]; then
    header="${header}: $*"
  fi
  echo "${CONTROL_SEQUENCE}H${header}"
 }

 fail_with() {
  set_response_code "$1"
  echo "$1 ${HTTP_RESPONSE[$1]}"
  return 1
 }

 serve_file() {
  local file="$( realpath $1)"; # works with links
  local length="$(stat -c'%s' "$file")"
  if [ $? -ne 0 ]; then
    fail_with 404
  else
    CONTENT_TYPE=
    case "$file" in
      *\.css)
        CONTENT_TYPE="text/css"
        ;;
      *\.js)
        CONTENT_TYPE="text/javascript"
        ;;
      *)
        CONTENT_TYPE="$(file -b --mime-type "$file")"
        ;;
    esac

    set_response_header "Content-Type" "$CONTENT_TYPE"
    # https://github.com/for-GET/know-your-http-well/blob/3cc5ab6d2764ab7aacb1b6e026abaccbeb6c37f2/json/headers.json#L21

    read -r CONTENT_LENGTH < <(stat -c'%s' "$file") && \
      set_response_header "Content-Length" "$CONTENT_LENGTH";
    # https://github.com/for-GET/know-your-http-well/blob/3cc5ab6d2764ab7aacb1b6e026abaccbeb6c37f2/json/headers.json#L27 Content-Length

    # if encodeing is acceptable then set encoding to gzip
    get_request_header "Accept-Encoding" | grep -q -e "gzip" && set_response_header  "Content-encoding" "gzip";
    # https://github.com/for-GET/know-your-http-well/blob/3cc5ab6d2764ab7aacb1b6e026abaccbeb6c37f2/json/headers.json#L3 Content-encoding

    cat "$file" | encodeing_gzip
    #sleep 0.5;
  fi
 }

 serve_dir_with_tree() {
  local dir="$1" tree_vers tree_opts basehref x

  set_response_header "Content-Type" "text/html"

  # The --du option was added in 1.6.0.
  read x tree_vers x < <(tree --version)
  [[ $tree_vers == v1.6* ]] && tree_opts="--du"

  tree -H "$2" -L 1 "$tree_opts" -D "$dir"
 }

 serve_dir_with_ls() {
  local dir=$1
  set_response_header "Content-Type" "text/plain"
  ls -la "$dir"
 }

 serve_dir() {
  # If `tree` is installed, use that for pretty output.
  if which tree &>/dev/null; then
    serve_dir_with_tree "$@"
  else
    serve_dir_with_ls "$@"
  fi
 }

 serve_dir_or_file_from() {
  local root="$1"
  local file="${3-${2-}}"
  local URL_PATH="${root}/${file}"

  # sanitize URL_PATH
  URL_PATH=${URL_PATH//[^a-zA-Z0-9_~\-\.\/]/}
  [[ $URL_PATH == *..* ]] && fail_with 400

  # Serve index file if exists in requested directory
  [[ -d $URL_PATH && -f $URL_PATH/index.html && -r $URL_PATH/index.html ]] && \
    URL_PATH="$URL_PATH/index.html"

  if [[ -f $URL_PATH ]] && [[ -r $URL_PATH ]]; then
    serve_file "$URL_PATH" "$@"
  elif [[ -d $URL_PATH ]] && [[ -x $URL_PATH ]]; then
    serve_dir  "$URL_PATH" "$@"
  fi
 }


 serve_static_string() {
  set_response_header "Content-Type" "${2-"text/plain"}"
  set_response_header "Content-Length" "$( echo "$1" | wc -c  )"
  # https://github.com/for-GET/know-your-http-well/blob/3cc5ab6d2764ab7aacb1b6e026abaccbeb6c37f2/json/headers.json#L27
  echo "$1"
 }

 # https://stackoverflow.com/a/37840948/376773
 decode_url() { : "${*//+/ }"; echo -e "${_//%/\\x}"; }

 get_request_header() {
  local name="$1"
  shopt -s nocasematch
  for header in "${REQUEST_HEADERS[@]}"; do
    if [[ "${header}" == "${name}:"* ]]; then
      local index="$((${#name} + 2))"
      echo "${header:$index}"
      return 0
    fi
  done

  # If we got to here then the header was not found
  return 1
 }

 get_request_body() {
  local length="$(get_request_header "content-length")"
  if [ ! -z "${length}" ]; then
    recv "Reading ${length} byte request body"
    read_bytes "${length}"
  else
    local encoding="$(get_request_header "transfer-encoding")"
    if [ "${encoding}" = "chunked" ]; then
      while IFS='' read -r line; do
        line=${line%%$'\r'}
        #recv "$line"

        length="$(printf "%d" "0x${line%%$'\n'}")"

        if [ "${length}" -gt 0 ]; then
          recv "Reading ${length} byte chunk"
          read_bytes "${length}"

          # The next two bytes are supposed to be '\r\n'
          #recv "Reading 2 byte end"
          # TODO: add verification
          read_bytes 2 > /dev/null
          recv "Done with chunk"
        else
          recv "Done reading chunked body"
          break
        fi
      done
    fi
  fi
 }

 on_uri_match() {
  local regex=$1
  shift
  [[ $REQUEST_URI =~ $regex ]] && "$@" "${BASH_REMATCH[@]}"
 }

 unconditionally() {
  "$@" "$REQUEST_URI"
 }

 run_user_code() {
  source "${conf}"
 }

 # https://github.com/for-GET/know-your-http-well/blob/3cc5ab6d2764ab7aacb1b6e026abaccbeb6c37f2/json/headers.json#L135 Accept-Encoding
 # https://web.archive.org/web/20170929183935/https://georgik.rocks/cgi-server-bash-one-liner/#gzip
 encodeing_gzip() {  get_request_header "Accept-Encoding"| grep -q -e "gzip" ; [ $? -eq 0 ] && gzip || cat ; }

 get_request_body | run_user_code | flush_response
	#!/usr/bin/env bash
	#
	###
	# https://gist.github.com/dubiouscript/e90a515b6ee2b5fe8988b945b0cdb418#this
	#
	# https://raw.githubusercontent.com/TooTallNate/bashttpd/master/bashttpd#origin
	#
	# https://raw.githubusercontent.com/TooTallNate/bashttpd/79582483264acad15b49e4b911f17f7bda753f43/bashttpd
	###
	#
	# https://github.com/for-GET/literate-http
	# https://learnxinyminutes.com/docs/bash/
	# https://github.com/pkrumins/bash-redirections-cheat-sheet
	# http://www.binaryphile.com/bash/2018/07/26/approach-bash-like-a-developer-part-1-intro.html
	# https://learnxinyminutes.com/docs/html/
	# https://developer.mozilla.org/en-US/docs/Web/HTML/Element
	# https://html.spec.whatwg.org/
	# https://learnxinyminutes.com/docs/javascript/
	# https://learnxinyminutes.com/docs/json/
	#
	# https://github.com/for-GET/know-your-http-well
	# https://github.com/for-GET/know-your-http-well/blob/master/json/methods.json
	# https://github.com/for-GET/know-your-http-well/blob/master/json/headers.json
	#
	# https://github.com/topics/http
	# https://github.com/topics/http?l=shell
	#
	##

	#
	# A simple, configurable HTTP server written in bash.
	#
	# See LICENSE for licensing information.
	#
	# Original author: Avleen Vig, 2012
	# Reworked by: Josh Cartwright, 2012
	# Reworked by: Nathan Rajlich, 2018
	# +gzip ,ect: ~dscr

	# If running as `root`, then downgrade to `nobody` first
	if [ "$EUID" -eq 0 ]; then
	exec sudo -u nobody "$0" "$@"
	fi

	conf="${BASHTTPD_CONFIG-bashttpd.conf}"

	[ -r "${conf}" ] \|\| {
	cat > "${conf}" <<'EOF'
	#
	# bashttpd.conf - configuration for bashttpd
	#
	# The behavior of bashttpd is dictated by the evaluation
	# of rules specified in this configuration file. Each rule
	# is evaluated until one is matched. If no rule is matched,
	# bashttpd will serve a 500 Internal Server Error.
	#
	# The format of the rules are:
	# on_uri_match REGEX command [args]
	# unconditionally command [args]
	#
	# on_uri_match:
	# On an incoming request, the URI is checked against the specified
	# (bash-supported extended) regular expression, and if encounters a match the
	# specified command is executed with the specified arguments.
	#
	# For additional flexibility, on_uri_match will also pass the results of the
	# regular expression match, ${BASH_REMATCH[@]} as additional arguments to the
	# command.
	#
	# unconditionally:
	# Always serve via the specified command. Useful for catchall rules.
	#
	# The following commands are available for use:
	#
	# serve_file FILE
	# Statically serves a single file.
	#
	# serve_dir_with_tree DIRECTORY
	# Statically serves the specified directory using 'tree'. It must be
	# installed and in the PATH.
	#
	# serve_dir_with_ls DIRECTORY
	# Statically serves the specified directory using 'ls -al'.
	#
	# serve_dir DIRECTORY
	# Statically serves a single directory listing. Will use 'tree' if it is
	# installed and in the PATH, otherwise, 'ls -al'
	#
	# serve_dir_or_file_from DIRECTORY
	# Serves either a directory listing (using serve_dir) or a file (using
	# serve_file). Constructs local path by appending the specified root
	# directory, and the URI portion of the client request.
	#
	# serve_static_string STRING
	# Serves the specified static string with Content-Type text/plain.
	#
	# Examples of rules:
	#
	# on_uri_match '^/issue$' serve_file "/etc/issue"
	#
	# When a client's requested URI matches the string '/issue', serve them the
	# contents of /etc/issue
	#
	# on_uri_match 'root' serve_dir /
	#
	# When a client's requested URI has the word 'root' in it, serve up
	# a directory listing of /
	#
	# DOCROOT=/var/www/html
	# on_uri_match '/(.*)' serve_dir_or_file_from "$DOCROOT"
	# When any URI request is made, attempt to serve a directory listing
	# or file content based on the request URI, by mapping URI's to local
	# paths relative to the specified "$DOCROOT"
	#

	#
	#
	match_between() { sed -n '/'"$1"'/,/'"$2"'/p'; }
	#####
	html_Page() { head="$1"; body="$2"; serve_static_string "<html><head> $head </head><body> $body </body></html>" "text/html" ; }
	html_link() { while read link text ; do [ -z "$link" ] \|\| echo '<a href='"$link>${text:-$link}"'</a></br>' ; done ; }
	##########

	# unconditionally serve_static_string 'Hello, world! You can configure bashttpd by modifying bashttpd.conf.'


	## http://humanstxt.org/
	##
	humans() { serve_static_string "$(cat $0 \| match_between "^# Original author" "^$" \| head -n-1 )" ; }
	#
	on_uri_match '^/humans.txt$' humans

	##
	svr_self() { serve_static_string "$(cat $0)" ; }
	#
	on_uri_match '^/bashttpd$' svr_self

	##
	svr_cfg() { serve_static_string "$( cat "${conf}" )" ; }
	#
	on_uri_match '^/bashttpd.conf$' svr_cfg

	###
	strip_comments() { sed '/^[[:blank:]]#/d;s/#.//' ; }
	svr_lst_routes() { cat "${conf}" \| strip_comments \| grep -e 'on_ur''i_match' \| awk '{print $2}' \| sed -e "s/^'\^//g" -e "s/\$'$//g" -e "s/\*'$//g" -e "s/'$//g" ; }

	default_route() { mod_cfg='Hello, world! You can configure bashttpd by modifying '"${conf}.";
	page_head="<title> Slash Bin Slash Bash </title>";
	page_body="$( svr_lst_routes \| sort \| uniq \| html_link) </br> $mod_cfg</hr>";
	html_Page "$page_head" "$page_body";
	}

	##
	#
	on_uri_match '^/$' default_route

	# More about commands:
	#
	# It is possible to somewhat easily write your own commands. An example
	# may help. The following example will serve "Hello, $x!" whenever
	# a client sends a request with the URI /say_hello_to/$x:
	#
	# serve_hello() {
	# set_response_header "Content-Type" "text/plain"
	# echo "Hello, $2!"
	# }
	# on_uri_match '^/say_hello_to/(.*)$' serve_hello
	#
	# Like mentioned before, the contents of ${BASH_REMATCH[@]} are passed
	# to your command, so its possible to use regular expression groups
	# to pull out info.
	#
	# With this example, when the requested URI is /say_hello_to/Josh, serve_hello
	# is invoked with the arguments '/say_hello_to/Josh' 'Josh',
	# (${BASH_REMATCH[0]} is always the full match)
	EOF
	echo "Created bashttpd.conf using defaults."
	echo "Please review it/configure before running bashttpd again."
	exit 1
	}

	recv() { echo "<" "$@" >&2; }
	send() { echo ">" "$@" >&2;
	printf "%s\r\n" "$*"; }

	read_bytes() {
	LANG=C IFS= read -r -d '' -n "$1" char
	printf "%s" "${char}"
	}

	DATE=$(date +"%a, %d %b %Y %H:%M:%S %Z")
	declare -a RESPONSE_HEADERS=(
	"Date: $DATE"
	"Expires: $DATE"
	"Server: Slash Bin Slash Bash"
	)

	add_response_header() {
	RESPONSE_HEADERS+=("$1: $2")
	}

	_add_response_header() {
	RESPONSE_HEADERS+=("$1")
	}

	# https://github.com/for-GET/know-your-http-well/blob/master/json/status-codes.json
	declare -a HTTP_RESPONSE=(
	[100]="Continue"
	[101]="Switching Protocols"
	[102]="Processing"
	[103]="Early Hints"
	[200]="OK"
	[201]="Created"
	[202]="Accepted"
	[203]="Non-Authoritative Information"
	[204]="No Content"
	[205]="Reset Content"
	[206]="Partial Content"
	[207]="Multi-Status"
	[208]="Already Reported"
	[226]="IM Used"
	[300]="Multiple Choices"
	[301]="Moved Permanently"
	[302]="Found"
	[303]="See Other"
	[304]="Not Modified"
	[305]="Use Proxy"
	[307]="Temporary Redirect"
	[308]="Permanent Redirect"
	[400]="Bad Request"
	[401]="Unauthorized"
	[402]="Payment Required"
	[403]="Forbidden"
	[404]="Not Found"
	[405]="Method Not Allowed"
	[406]="Not Acceptable"
	[407]="Proxy Authentication Required"
	[408]="Request Timeout"
	[409]="Conflict"
	[410]="Gone"
	[411]="Length Required"
	[412]="Precondition Failed"
	[413]="Payload Too Large"
	[414]="URI Too Long"
	[415]="Unsupported Media Type"
	[416]="Range Not Satisfiable"
	[417]="Expectation Failed"
	[418]="I'm a teapot"
	[421]="Misdirected Request"
	[422]="Unprocessable Entity"
	[423]="Locked"
	[424]="Failed Dependency"
	[425]="Unordered Collection"
	[426]="Upgrade Required"
	[428]="Precondition Required"
	[429]="Too Many Requests"
	[431]="Request Header Fields Too Large"
	[451]="Unavailable For Legal Reasons"
	[500]="Internal Server Error"
	[501]="Not Implemented"
	[502]="Bad Gateway"
	[503]="Service Unavailable"
	[504]="Gateway Timeout"
	[505]="HTTP Version Not Supported"
	[506]="Variant Also Negotiates"
	[507]="Insufficient Storage"
	[508]="Loop Detected"
	[509]="Bandwidth Limit Exceeded"
	[510]="Not Extended"
	[511]="Network Authentication Required"
	)

	send_response_header() {
	local code=$1
	send "HTTP/1.0 ${code} ${HTTP_RESPONSE[${code}]}"
	for i in "${RESPONSE_HEADERS[@]}"; do
	send "$i"
	done
	send
	}

	_fail_with() {
	send_response_header "$1"
	echo "$1 ${HTTP_RESPONSE[$1]}"
	exit 1
	}

	# Request-Line HTTP RFC 2616 $5.1
	IFS='' read -r line \|\| _fail_with 400

	# strip trailing CR if it exists
	line=${line%%$'\r'}
	recv "$line"

	read -r REQUEST_METHOD REQUEST_URI REQUEST_HTTP_VERSION <<<"$line"

	[ -n "$REQUEST_METHOD" ] && \
	[ -n "$REQUEST_URI" ] && \
	[ -n "$REQUEST_HTTP_VERSION" ] \
	\|\| _fail_with 400

	REQUEST_PATH="${REQUEST_URI%%\?*}"
	QUERY_STRING="${REQUEST_URI#*\?}"

	declare -a REQUEST_HEADERS

	while IFS='' read -r line; do
	line=${line%%$'\r'}
	recv "$line"

	# If we've reached the end of the headers, break.
	[ -z "$line" ] && break

	REQUEST_HEADERS+=("$line")
	done

	CONTROL_SEQUENCE=$'\1'

	flush_response() {
	# Wait for response code and header "events" from stdin
	local code=200
	local buf
	while true; do
	local buf="$(read_bytes "${#CONTROL_SEQUENCE}")"
	#recv "buf: $(printf "%x " "'${buf}") ${#buf}"
	if [ "${buf}" = "${CONTROL_SEQUENCE}" ]; then
	IFS='' read -r line
	line=${line%%$'\r'}
	#recv "line: ${line}"
	local cmd="${line:0:1}"
	local data="${line:1}"
	case "${cmd}" in
	C) code="${data}";;
	H) _add_response_header "${data}";;
	esac
	else
	break
	fi
	done
	send_response_header "${code}"
	printf "%s" "${buf}"
	cat
	}

	# Set the response status code.
	# MUST be called before any output is generated by your script.
	set_response_code() {
	echo "${CONTROL_SEQUENCE}C$1"
	}

	# Sets a response header.
	# MUST be called before any output is generated by your script.
	set_response_header() {
	local header="$1"
	shift
	if [ $# -ne 0 ]; then
	header="${header}: $*"
	fi
	echo "${CONTROL_SEQUENCE}H${header}"
	}

	fail_with() {
	set_response_code "$1"
	echo "$1 ${HTTP_RESPONSE[$1]}"
	return 1
	}

	serve_file() {
	local file="$( realpath $1)"; # works with links
	local length="$(stat -c'%s' "$file")"
	if [ $? -ne 0 ]; then
	fail_with 404
	else
	CONTENT_TYPE=
	case "$file" in
	*\.css)
	CONTENT_TYPE="text/css"
	;;
	*\.js)
	CONTENT_TYPE="text/javascript"
	;;
	*)
	CONTENT_TYPE="$(file -b --mime-type "$file")"
	;;
	esac

	set_response_header "Content-Type" "$CONTENT_TYPE"
	# https://github.com/for-GET/know-your-http-well/blob/3cc5ab6d2764ab7aacb1b6e026abaccbeb6c37f2/json/headers.json#L21

	read -r CONTENT_LENGTH < <(stat -c'%s' "$file") && \
	set_response_header "Content-Length" "$CONTENT_LENGTH";
	# https://github.com/for-GET/know-your-http-well/blob/3cc5ab6d2764ab7aacb1b6e026abaccbeb6c37f2/json/headers.json#L27 Content-Length

	# if encodeing is acceptable then set encoding to gzip
	get_request_header "Accept-Encoding" \| grep -q -e "gzip" && set_response_header "Content-encoding" "gzip";
	# https://github.com/for-GET/know-your-http-well/blob/3cc5ab6d2764ab7aacb1b6e026abaccbeb6c37f2/json/headers.json#L3 Content-encoding

	cat "$file" \| encodeing_gzip
	#sleep 0.5;
	fi
	}

	serve_dir_with_tree() {
	local dir="$1" tree_vers tree_opts basehref x

	set_response_header "Content-Type" "text/html"

	# The --du option was added in 1.6.0.
	read x tree_vers x < <(tree --version)
	[[ $tree_vers == v1.6* ]] && tree_opts="--du"

	tree -H "$2" -L 1 "$tree_opts" -D "$dir"
	}

	serve_dir_with_ls() {
	local dir=$1
	set_response_header "Content-Type" "text/plain"
	ls -la "$dir"
	}

	serve_dir() {
	# If `tree` is installed, use that for pretty output.
	if which tree &>/dev/null; then
	serve_dir_with_tree "$@"
	else
	serve_dir_with_ls "$@"
	fi
	}

	serve_dir_or_file_from() {
	local root="$1"
	local file="${3-${2-}}"
	local URL_PATH="${root}/${file}"

	# sanitize URL_PATH
	URL_PATH=${URL_PATH//[^a-zA-Z0-9_~\-\.\/]/}
	[[ $URL_PATH == .. ]] && fail_with 400

	# Serve index file if exists in requested directory
	[[ -d $URL_PATH && -f $URL_PATH/index.html && -r $URL_PATH/index.html ]] && \
	URL_PATH="$URL_PATH/index.html"

	if [[ -f $URL_PATH ]] && [[ -r $URL_PATH ]]; then
	serve_file "$URL_PATH" "$@"
	elif [[ -d $URL_PATH ]] && [[ -x $URL_PATH ]]; then
	serve_dir "$URL_PATH" "$@"
	fi
	}


	serve_static_string() {
	set_response_header "Content-Type" "${2-"text/plain"}"
	set_response_header "Content-Length" "$( echo "$1" \| wc -c )"
	# https://github.com/for-GET/know-your-http-well/blob/3cc5ab6d2764ab7aacb1b6e026abaccbeb6c37f2/json/headers.json#L27
	echo "$1"
	}

	# https://stackoverflow.com/a/37840948/376773
	decode_url() { : "${*//+/ }"; echo -e "${_//%/\\x}"; }

	get_request_header() {
	local name="$1"
	shopt -s nocasematch
	for header in "${REQUEST_HEADERS[@]}"; do
	if [[ "${header}" == "${name}:"* ]]; then
	local index="$((${#name} + 2))"
	echo "${header:$index}"
	return 0
	fi
	done

	# If we got to here then the header was not found
	return 1
	}

	get_request_body() {
	local length="$(get_request_header "content-length")"
	if [ ! -z "${length}" ]; then
	recv "Reading ${length} byte request body"
	read_bytes "${length}"
	else
	local encoding="$(get_request_header "transfer-encoding")"
	if [ "${encoding}" = "chunked" ]; then
	while IFS='' read -r line; do
	line=${line%%$'\r'}
	#recv "$line"

	length="$(printf "%d" "0x${line%%$'\n'}")"

	if [ "${length}" -gt 0 ]; then
	recv "Reading ${length} byte chunk"
	read_bytes "${length}"

	# The next two bytes are supposed to be '\r\n'
	#recv "Reading 2 byte end"
	# TODO: add verification
	read_bytes 2 > /dev/null
	recv "Done with chunk"
	else
	recv "Done reading chunked body"
	break
	fi
	done
	fi
	fi
	}

	on_uri_match() {
	local regex=$1
	shift
	[[ $REQUEST_URI =~ $regex ]] && "$@" "${BASH_REMATCH[@]}"
	}

	unconditionally() {
	"$@" "$REQUEST_URI"
	}

	run_user_code() {
	source "${conf}"
	}

	# https://github.com/for-GET/know-your-http-well/blob/3cc5ab6d2764ab7aacb1b6e026abaccbeb6c37f2/json/headers.json#L135 Accept-Encoding
	# https://web.archive.org/web/20170929183935/https://georgik.rocks/cgi-server-bash-one-liner/#gzip
	encodeing_gzip() { get_request_header "Accept-Encoding"\| grep -q -e "gzip" ; [ $? -eq 0 ] && gzip \|\| cat ; }

	get_request_body \| run_user_code \| flush_response