Shell script to download IMDb data files

retrieve-imdb-tsv.sh

#!/bin/bash
# Purpose:  bash script to retrieve IMDb tsv files described at https://www.imdb.com/interfaces/
# Created:  2018-10-03
# Requires: bash, date, mkdir, pushd, wget, ls, du, gzip, popd
#           writing rights and enough space (~ 650 MB as of 2018) in argument directory

# make sure the script has exactly one argument, otherwise exit with usage instructions
if [ -z "$1" ]; then
  echo "Usage:   '$0 <directory>' to download IMDb tsv files to 'directory/YYYY/YYYY-MM-DD'."
  echo "Note:    <directory> must exist already, subdirectories will be created."
  echo "Example: '$0 ~/imdb' will download to '~/imdb/2018/2018-10-03' if script got called on October 3rd, 2018."
  exit 1
fi

# make sure argument is existing directory
DEST_DIR="$1"
if [ ! -d "$DEST_DIR" ]; then
  printf "Error: Argument directory '%s' does not exist.\n" "$DEST_DIR"
  exit 1
fi

# store today's date in variable: year + slash + full date
DATE=$(date '+%Y/%Y-%m-%d')

# create subdirectories in destination directory
DEST_DIR="${DEST_DIR}/${DATE}"
mkdir -p "$DEST_DIR"
ERROR_CODE=$?
if [ $ERROR_CODE != 0 ] ; then
  echo "Error: Could not create directory '$DEST_DIR' (error code ${ERROR_CODE})."
  exit 1
fi

# go to today's directory
pushd "$DEST_DIR" || exit

# retrieve files
wget -e robots=off --no-verbose -np -nd -nc -r -l 1 -A gz https://datasets.imdbws.com
ERROR_CODE=$?
if [ $ERROR_CODE != 0 ] ; then
  echo "Error: Failed to retrieve files to directory '$DEST_DIR' (error code ${ERROR_CODE})."
  popd || exit
  exit 1
fi

# print information on downloaded files
ls -al
du -h

# test integrity of files
echo "Success. Testing files:"
gzip -t -v ./*.gz

# go back to original directory
popd || exit