#!/bin/bash

function fd_available() {
         for i in {1..65536}; do
             if [ ! -e /proc/$$/fd/$i ]; then
                 echo $i;
                 return 0;
             fi
         done

         return 1;
}

function fd_open() {
         local fd=$1;
         local mode=$2
         local path=$3;

         case $mode in
             r)
                 eval "exec $fd<$path";;
             w)
                 eval "exec $fd>$path";;
             rw)
                 eval "exec $fd<>$path";;
             *)
                 false;;
         esac
}


function fd_cat() {
         local fd=$1;

         eval "cat <&$fd";
}


function fd_write() {
         local fd=$1;
         shift;
         local msg="$@";

         eval "echo $@ >&$fd";
}


function fd_close() {
         local fd=$1;

         eval "exec $fd>&-";
}


function fd_based_example() {
    TEST fd=`fd_available`;
    TEST fd_open $fd "rw" $M0/filename;
    TEST fd_cat $fd; # print existing stuff
    TEST fd_write $fd "new stuff"; # append
    TEST fd_close $fd;
}