Download a weather dataset from the National Climatic Data Center (NCDC, http://www .ncdc.noaa.gov/). Prepare it for examples of "Hadoop: The Definitive Guide" book by Tom White. http://www.amazon.com/Hadoop-Definitive-Guide-Tom-White/dp/1449311520Usage:./ncdc.sh 1901 1930 # download wheather datasets for period from 1901 to 1930.
#!/usr/bin/env bash
# global parameters
g_tmp_folder="ncdc_tmp";
g_output_folder="ncdc_data";
g_remote_host="ftp.ncdc.noaa.gov";
g_remote_path="pub/data/noaa";
# $1: folder_path
function create_folder {
if [ -d "$1" ]; then
rm -rf "$1";
fi
mkdir "$1"
}
# $1: year to download
function download_data {
local source_url="ftp://$g_remote_host/$g_remote_path/$1"
wget -r -c -q --no-parent -P "$g_tmp_folder" "$source_url";
}
# $1: year to process
function process_data {
local year="$1"
local local_path="$g_tmp_folder/$g_remote_host/$g_remote_path/$year"
local tmp_output_file="$g_tmp_folder/$year"
for file in $local_path/*; do
gunzip -c $file >> "$tmp_output_file"
done
zipped_file="$g_output_folder/$year.gz"
gzip -c "$tmp_output_file" >> "$zipped_file"
echo "created file: $zipped_file"
rm -rf "$local_path"
rm "$tmp_output_file"
}
# $1 - start year
# $2 - finish year
function main {
local start_year=1901
local finish_year=2001
if [ -n "$1" ]; then
start_year=$1
fi
if [ -n "$2" ]; then
finish_year=$2
fi
create_folder $g_tmp_folder
create_folder $g_output_folder
for year in `seq $start_year $finish_year`; do
download_data $year
process_data $year
done
rm -rf "$g_tmp_folder"
}
main $1 $2