Webserver in 100 Zeilen Bash

In Piotr Gabryjeluks Blog habe ich ein interessantes Skript gefunden, welches einen Webserver in 100 Zeilen Bash enthält. Als Parameter erwartet das Skript eine Portnummer, auf die es lauschen soll.

Für Ubuntu muss dieses Skript angepasst werden, da das dort installierte netcat andere Optionen versteht. Das Original kann von obiger Webseite heruntergeladen werden, das für Ubuntu angepasste folgt hier und kann auch als Datei heruntergeladen werden:

#!/bin/bash
#
# httpd.bash :
# webserver in 100 lines of bash.
#
# credits: http://piotr.gabryjeluk.pl/www-server-in-100-lines-bash-script
#
# This software should be quite safe, since this checks for some nasty tricks like:
# .. in URL
# / in some places
# It binds to port specified from the command line.
# It serves only files accessible by the user that runs this script from the current directory (not going up).
#
# dependencies:
# This script depends on nc (netcat package) being installed in PATH.
# If you have nc instead of netcat, just change the netcat in script to nc.
 
function debug {
    local severity="$1"
    shift
    local message="$@"
 
    echo -n "`date -u`"    1>&2
    echo -ne '\t'        1>&2
    echo -n "$severity"    1>&2
    echo -ne '\t'        1>&2
    echo "$message"        1>&2
}
 
function fix_path {
    echo -n "$1" | head -n 1 | sed 's|^[/.-]*||' | sed 's|/\.*|/|g'
}
 
function serve_dir {
    local dir="`fix_path "$1"`"
    if [ "$dir" = "" ]; then
        dir="./"
    fi
    echo 'HTTP/1.1 200 OK'
    echo 'Content-type: text/html;charset=UTF-8'
    echo
    echo LISTING "$dir"
    echo '<br/>'
    ls -p "$dir" | sed -e 's|^\(.*\)$|<a href="/'"$dir"'\1">\1</a><br/>|'
}
 
function serve_file {
    echo 'HTTP/1.1 200 OK'
    echo 'Content-type: application/x-download-this'
    echo
    local file="`fix_path "$1"`"
    debug INFO serving file "$file"
    cat "$file"
}
 
function process {
    local url="`gawk '{print $2}' | head -n 1`"
    case "$url" in
        */)
            debug INFO Processing "$url" as dir
            serve_dir "$url"
            break
            ;;
        *)
            debug INFO Processing "$url" as file
            serve_file "$url"
            ;;
    esac
}
 
function serve {
    local port="$1"
    local sin="$2"
    local sout="$3"
 
    while debug INFO Running nc; do
 
        netcat -l "$port" < "$sin" > "$sout" &
        pid="$!"
 
        debug INFO Server PID: "$pid"
 
        trap cleanup SIGINT
        head -n 1 "$sout" | process > "$sin"
        trap - SIGINT
    done
 
    debug INFO Quiting server
}
 
function cleanup {
    debug INFO Caught signal, quitting...
    rm -Rf "$tmp_dir"
	kill "$pid"
    exit
}
 
tmp_dir="`mktemp -d -t http_server.XXXXXXXXXX`"
sin="$tmp_dir"/in
sout="$tmp_dir"/out
pid=0
port="$1"
 
mkfifo "$sin"
mkfifo "$sout"
 
debug INFO Starting server on port "$port"
serve "$port" "$sin" "$sout"
cleanup