#!/bin/bash
# from http://blog.ksplice.com/2011/01/solving-problems-with-proc/
# amended by MFONTANI at CPAN.org
if [[ -z "$1" ]]; then
  echo Need a PID
  exit 1
fi
if [[ -z "$2" ]]; then
  echo "Need a FD number for PID $1"
  echo "Choose from:"
  ls -la /proc/$1/fd/
  exit 1
fi
fd=/proc/$1/fd/$2
fdinfo=/proc/$1/fdinfo/$2
name=$(readlink $fd)
size=$(wc -c $fd | awk '{print $1}')
while [ -e $fd ]; do
  progress=$(cat $fdinfo | grep ^pos | awk '{print $2}')
  echo $((100*$progress / $size))
  sleep 1
done | dialog --gauge "Progress reading $name" 7 100