gopherd.sh

   1 #!/bin/bash
   2
   3 # Note: bash is required, sh will fail to output anything to the client
   4 # Probably related to interactions beteween & and output redirections
   5 #
   6 # It seems the timeout on netcat does not work when listening...
   7 # So you will have to either kill the process or make a last connection
   8 # (which will not be processed)
   9
  10 # $0 [prog] ([port])
  11 # You can use the evironment variable $QUERY_STRING for the query
  12
  13 [ "$ADDR"    = "" ] && ADDR=127.0.0.1
  14 [ "$LOG"     = "" ] && LOG=/tmp/gopher.service.err
  15 [ "$PIDF"    = "" ] && PIDF="`mktemp`"
  16 [ "$TIMEOUT" = "" ] && TIMEOUT=10
  17 [ "$MAXCON"  = "" ] && MAXCON=1024
  18
  19 prog="$1"
  20 port="$2"
  21 defn="$3"
  22 [ "$port"    = "" ] && port=70
  23
  24 if [ "$prog" = "" ]; then
  25         rm "$PIDF"
  26         echo "Syntax: $0 [prog] ([port]) (default non-7)" >&2
  27         echo '  You can use the evironment variable $QUERY_STRING for the query' >&2
  28         echo '  The default port is 70' >&2
  29         echo '  A default message for non-service (7) request can be given' >&2
  30         echo '  A filename will be displayed, you can delete it to stop the service' >&2
  31         echo '  (you still have to make a last connection on $port)' >&2
  32         exit 1
  33 fi
  34
  35 tmpd=`mktemp -t -d .gopher-service.XXXXXX`
  36 if [ ! -d "$tmpd" ]; then
  37         rm "$PIDF"
  38         echo "Cannot create temporary directory, aborting..." >&2
  39         exit 2
  40 fi
  41
  42 echo "#!/bin/sh
  43 # PID: $$
  44 # PID File (this file): $PIDF
  45 # You can stop the service by deleting this file then making a last
  46 # connection (which will not be processed) to the service:
  47 rm \"$PIDF\"
  48 nc -q0 $ADDR $port 2>/dev/null </dev/null
  49 " > "$PIDF"
  50
  51 chmod u+rx "$PIDF"
  52
  53 echo "$PIDF"
  54
  55 i=0
  56 while [ -e "$PIDF" ]; do
  57         i=`expr $i + 1`
  58         [ $i -gt "$MAXCON" ] && i=1
  59         fifo="$tmpd/fifo.$i"
  60         rm -f "$fifo" 2>/dev/null
  61         mkfifo "$fifo"
  62         < "$fifo" nc -l -q0 -w"$TIMEOUT" "$ADDR" -p "$port" | (
  63                 if [ -e "$PIDF" ]; then
  64                         read -r query
  65                         selector="`echo "$query" | cut -f1 -d'  ' | sed 's:[\r\n]::g'`"
  66                         query="`echo "$query" | cut -f2 -d'     ' | sed 's:[\r\n]::g'`"
  67                         if [ "$query" = "" ]; then
  68                                 if [ "$defn" = "" ]; then
  69                                         echo "7Search   $selector       $ADDR   $port"
  70                                 else
  71                                         echo "$defn"
  72                                 fi
  73                         else
  74                                 QUERY_STRING="$query" "$prog" 2>> "$LOG" &
  75                         fi
  76                 fi
  77         ) > "$fifo"
  78 done
  79 rm -rf "$tmpd" 2>/dev/null
  80