Bash script to move files into batched folders for easier processing. For example if there were 50k files and you needed them in 200 file chunks, you would call this to move the 50k into folders of 200 files each.

batch-folders.sh

#!/bin/bash
# Usage: batch-folders.sh /Where/To/Look 5000
# This will create 5000-large batch folders within /Where/To/Look

FolderPath="$1"
HowManyToBatch="$2"
BatchFolder="Batch_"

# check if number of arguments is right
if [ ! $# == 2 ]; then
  echo "Usage: $0 folder_path number_of_files_per_batch"
  exit 1
fi

# check if folder exists
if [ ! -d "$FolderPath" ]; then
    echo "Error: Path does not exist: $FolderPath"
    exit 1
fi

# check if batch is a real number
re='^[0-9]+$'
if ! [[ $HowManyToBatch =~ $re ]] ; then
   echo "Error: Not a number: $HowManyToBatch"
   exit 1
fi

# figure out how many files there are
echo "Counting the files to divide..."
NumberToDivide=$(find "$FolderPath" -type f -d 1 \( ! -iname ".*" \) | wc -l)
echo "There are $NumberToDivide files to batch"

# figure out how many batches will be needed for the number of files
temp=$(expr $NumberToDivide + $HowManyToBatch - 1)
batches=$(expr $temp / $HowManyToBatch )
echo "Calculated that $batches batches will be needed."
echo "$NumberToDivide / $HowManyToBatch = $batches batches"

# prepare batch folders
for i in $(seq 1 $batches); do
	mkdir "$FolderPath"/$BatchFolder$i
done

# start moving content into batch folders
batch=1
count=1
for f in $(find "$FolderPath" -type f -d 1 \( ! -iname ".*" \)); do
	if [ "$count" -gt "$HowManyToBatch" ]; then
		count=1
		batch=$(expr $batch + 1)
		if [ "$batch" -gt "$batches" ]; then
			echo "Uh oh, I was about to move a file into an uncreated folder"
			exit 1
		fi
	fi
	echo "Starting Batch $batch"
	file=$(basename "$f")
	mv -v "$f" "$FolderPath"/$BatchFolder$batch/"$file"
	count=$(expr $count + 1)
done