make_test_file_tree.sh

#!/bin/bash -e
# Make a balanced file tree with files full of random bytes for testing purposes.
# Script takes three parameters depth, width, and filesize.
DEPTH=2
WIDTH=10
FSIZE=10000
DORANDOM=1
#WRITEPROBABILITY=5

function rec_make_tree() {
  local DEPTH=$1
  local WIDTH=$2
  local FSIZE=$3
  local MYDIR=${4:-.}
  local i
  for (( i=0; $i<$WIDTH; i=$i+1 ))
  do
    if [[ $DEPTH -gt 0 ]]; then
      [[ -d $MYDIR/$i ]] || mkdir $MYDIR/$i
      rec_make_tree $(($DEPTH-1)) $WIDTH $FSIZE $MYDIR/$i
    else
      if [[ ( -z "$DORANDOM" ) || ( $(($RANDOM%${WRITEPROBABILITY:-1})) -eq 0 ) ]]; then
        head -c $FSIZE /dev/urandom > $MYDIR/$i
        #echo yes
      else
        true
        #echo no
      fi
    fi
  done
}

DEPTH=${1:-$DEPTH}
WIDTH=${2:-$WIDTH}
FSIZE=${3:-$FSIZE}
echo "Making a file tree with DEPTH=$DEPTH WIDTH=$WIDTH FILESIZE=$FSIZE"
rec_make_tree $DEPTH $WIDTH $FSIZE .