#!/bin/bash
sha1rec () {
  if [ -d ${1} ]; then
    NEXTDIR=${1}
    echo "descending into $NEXTDIR"
  fi
  if [ ! -d ${1} ]; then
    if [ -d `pwd`/${1} ]; then
      NEXTDIR=`pwd`/${1}
      echo "descending into $NEXTDIR"
    fi
  fi
  if [ ! $NEXTDIR ]; then
    echo "Usage: sha1rec [directory]"
    exit 1
  fi
  PREVDIR=`pwd`
  cd $NEXTDIR
  rm sha1sums.txt
  for i in *; do
    if [ -d $i ]; then
      sha1rec $i
    else
      if [ -f $i ]; then
        if [ "$i" != "md5sums.txt" ]; then
          if [ "$i" != "sha1sums.txt" ]; then
            sha1sum $i >> sha1sums.txt
          fi
        fi
      fi
    fi
  done
  cd ..
}

sha1rec ${1}