Create (small) dummy data in Bash.

generate_stuff.sh

#!/usr/bin/env bash
#
# generate_stuff
#
# Create dummy data. Used as a sandbox for testing: 
# https://gist.github.com/marshki/693ad8682cd14cc11f8ff4babeb47ca7
#
# Author: M. Krinitz <mjk235 [at] nyu [dot] edu>
# Date: 2020.03.01
# License: MIT
#
#===============================================================
# Step 1: Create files/dirs in: /tmp/sigma.
# Step 2: Create random output to nth item in: /tmp/sigma/alpha.
# Step 3: Duplicate nth files/dirs to: /tmp/sigma/bravo.
#===============================================================

SANDBOX="/tmp/sigma"

# Check if '/tmp/sigma' directory exists. Exit if yes.

check_for_directory () {

  if [ -d "$SANDBOX" ]; then
    printf "%s\\n" "Directory $SANDBOX already exists. Exiting."
    exit 0
  fi
}

# Create /tmp/sigma dir with subdirs.

make_directory () {

  printf "%s\\n" "Creating 'sigma' dir & subdirs in /tmp..."
  mkdir -p $SANDBOX/{alpha,bravo}/{charlie,delta,echo}
}

# Populate dirs in /tmp/sigma/alpha with files.

make_files () {

  printf "%s\\n" "Creating files in /tmp/sigma/alpha..."
  find $SANDBOX/alpha -type d -exec touch {}/foxtrot{0..9} \;
}

# Generate 1024 KBs of random data to nth file.

random_data_nth_files () {

  for item in $(find "$SANDBOX"/alpha -type f |awk 'NR % 2 == 0'); do
    printf "%s\\n" "Writing random data to $item."
    head -c 1024 </dev/urandom > "$item"
  done
}

# Duplicate every nth file or dir in /tmp/sigma/alpha to /tmp/sigma/bravo/.

copy_nth_files_dirs () {

  for item in $(find $SANDBOX/alpha -type f -or -type d |awk 'NR % 3 == 0'); do
    printf "%s\\n" "Copying $item to $SANDBOX/bravo."
    cp -rp "$item" $SANDBOX/bravo/
  done
}

# Exit status check.

exit_status () {
  if [[ $retVal -ne 0 ]]; then
    printf "%s\\n" "Something went wrong, homie..."
  else
    printf "%s\\n" "Done."
  fi
}

# Wrapper.

main () {
  check_for_directory
  make_directory
  make_files
  random_data_nth_files
  copy_nth_files_dirs
}

main "$@"

retVal=$?
exit_status