#!/bin/bash
rm -r Big_Dir
mkdir Big_Dir
echo Directory Big_Dir created
mkdir Big_Dir/Small_Dir
echo Subdirectory Small_Dir created
for i in {1..15}
do
  echo First line of Document_$i.txt > Big_Dir/Small_Dir/Document_$i.txt
  echo Second line of Document_$i.txt >> Big_Dir/Small_Dir/Document_$i.txt
  if [ $i -eq 15 ]
  then
    echo Next document does not exist >> Big_Dir/Small_Dir/Document_$i.txt
  else
    j=$((i+1))
    echo Next document is Document_$j.txt >> Big_Dir/Small_Dir/Document_$i.txt
  fi
done

cd Big_Dir
echo Regular files of Big_Dir
files=`find . -maxdepth 1 -type f`
for f in $files
do
  echo `basename $f`
done

cd Small_Dir
echo Regular files of Small_Dir
files=`find . -maxdepth 1 -type f`
for f in $files
do
  echo `basename $f`
done

for i in {1..15}
do
  #cat1=`cat Document_$i.txt`
  #echo $cat1
  echo "$(cat Document_$i.txt)"
  echo +++++++++++++++
done

for f in $files
do
  if [ -n "$(grep '1\|2' $f)" ]
  then
    mv $f ~/Big_Dir
  fi
done

#echo `pwd` aaaaa

cd ..
echo Contents of Big_Dir
echo "$(ls)"
echo Contents of Small_Dir
cd Small_Dir
echo "$(ls)"

cd ..
files=`find . -maxdepth 1 -type f`
touch ConCat
for f in $files
do
  c=$(cat $f)
  echo $c
  #echo $c >> ConCat
done