script trivia

exportfs

#!/bin/bash

# micro fileserver

echo "exportfs: server initiated" | logger

if [ "$#" -ne 1 ]; then
  echo "Usage: exportfs EXPORT_BASE"
  exit
fi

EXPORT_BASE=$(echo $1 | sed 's@/$@@')

CR=`printf '\r'`

fetch() {
  local obj=$1

  echo "exportfs: command $obj received" | logger

  # if it's a directory show it's contents
  if [ -d "$obj" ]; then
    find "$obj" -maxdepth 1 \( -type d -printf "%p/\n" , -type f -print \)
    return
  fi

  #if it's a file show it's contents too
  if [ -f "$obj" ]; then
    cat "$obj"
  else
    return
  fi
}

main_loop() {

  trap=40  
  while read -t 15 -n 4096 input; do
    trap=$(expr ${trap} - 1) 

    echo "exportfs: recevied $input as raw materials" | logger

    obj=$(/bin/readlink -e "${input%$CR}" | /bin/sed 's@//@/@g;s@/$@@;s@^$@/@')
   
 
    case "$obj" in
      "$EXPORT_BASE"*) fetch "$obj";;
      *) echo "exportfs: invalid command received" | logger; exit 1;;
    esac

    if [ "$trap" -lt 0 ]; then
      echo "exportfs: trap for number of operations exceded" | logger
      exit 1
    fi 
  done
  
  echo "exportfs: timeout trap exeeded" | logger
  exit 1
}

main_loop