gopher.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 # $0 [prog] ([port])
   7 # You can use the evironment variable $QUERY_STRING for the query
   8
   9 [ "$ADDR"    = "" ] && ADDR=127.0.0.1
  10 [ "$LOG"     = "" ] && LOG=/tmp/gopher.service.err
  11 [ "$PIDF"    = "" ] && PIDF="`mktemp`"
  12 [ "$TIMEOUT" = "" ] && TIMEOUT=10
  13 [ "$MAXCON"  = "" ] && MAXCON=1024
  14
  15 prog="$1"
  16 port="$2"
  17 [ "$port"    = "" ] && port=70
  18
  19 if [ "$prog" = "" ]; then
  20         rm "$PIDF"
  21         echo "Syntax: $0 [prog] ([port])" >&2
  22         echo '  You can use the evironment variable $QUERY_STRING for the query' >&2
  23         echo '  The default port is 70' >&2
  24         echo '  A filename will be displayed, you can delete it to stop the service' >&2
  25         echo '  (with a grace time of $TIMEOUT seconds)' >&2
  26         exit 1
  27 fi
  28
  29 tmpd=`mktemp -t -d .gopher-service.XXXXXX`
  30 if [ ! -d "$tmpd" ]; then
  31         rm "$PIDF"
  32         echo "Cannot create temporary directory, aborting..." >&2
  33         exit 2
  34 fi
  35
  36 touch "$PIDF"
  37 echo "$PIDF"
  38
  39 i=0
  40 while [ -e "$PIDF" ]; do
  41         i=`expr $i + 1`
  42         [ $i -gt "$MAXCON" ] && i=1
  43         fifo="$tmpd/fifo.$i"
  44         rm -f "$fifo" 2>/dev/null
  45         mkfifo "$fifo"
  46         < "$fifo" nc -l -q0 -w"$TIMEOUT" "$ADDR" -p "$port" | (
  47                 read -r query
  48                 query="`echo "$query" | cut -f2 -d'     ' | sed 's:[\r\n]::g'`"
  49                 QUERY_STRING="$query" "$prog" 2>> "$LOG" &
  50         ) > "$fifo"
  51 done
  52 rm -rf "$tmpd" 2>/dev/null