Move 2000 PDFs in several folders, each containing 100 files

Question

I have one folder with 2000 PDF files on a Mac. Using the command line, I would like to move each 100 PDFs to another folder to be created in the same directory. So that I would have 20 folders (named 1, 2, etc.) each containing 100 PDFs in the main directory. How can I achieve that?

Answer 1

You could use set, process batches of 100 files via "${@:START:COUNT}" (range of positional parameters) and shift 100 while incrementing a counter c to create the directories:

set -- *.pdf
c=1
while (($#)); do
  mkdir ${c}
  if [ $# -ge 100 ]; then
    mv -- "${@:1:100}" ${c}
    c=$((c+1))
    shift 100
  else
    mv -- "${@}" ${c}
    shift $#
  fi
done

Answer 2

I have just written below bash script for your specific problem. This may help you.

#!/bin/bash

DEFAULT_DELIM_SIZE=100
num_of_total_file=$(ls | grep "pdf" | wc -l)
num_of_total_folder=$((num_of_total_file/DEFAULT_DELIM_SIZE))

echo "Total number of pdf files = $num_of_total_file"
echo "Total number of folder will generated if not exist $num_of_total_folder"

# create directories if not exist
for (( i = 0; i < $num_of_total_folder; i++ )); do
    if [[ ! -d $i ]]; then
        mkdir $i
    fi
done

# file name format should be like this <arbitrary_numb>-<folder_num>.pdf
for file in *.pdf; do
    prefix=$(echo $file | awk '{split($0, a, "-"); print a[2]}' | awk '{split($0, a, "."); print a[1]}')
    if [[ -d $prefix ]]; then
        mv $file $prefix
    fi
done