Linux – Delete logs older than 30 days

# list files
keep_days=30
pattern1='*.log.*'
pattern2='*.gz'
file_path='/var/log/'


function bytes_for_humans {
    local -i bytes=$1;
    if [[ $bytes -lt 1024 ]]; then
        echo "${bytes}B"
    elif [[ $bytes -lt 1048576 ]]; then
        echo "$(( (bytes + 1023)/1024 ))KiB"
    else
        echo "$(( (bytes + 1048575)/1048576 ))MiB"
    fi
}


initial_size=$(sudo du -s $file_path  | cut -f1)
sudo find $file_path \( -name "${pattern1}" -o -name "${pattern2}" \) -type f -mtime +$keep_days -exec sudo rm {} \;
# sudo find $file_path \( -name "${pattern1}" -o -name "${pattern2}" \) -type f;
# sudo find $file_path \( -name "${pattern1}" -o -name "${pattern2}" \) -type f -exec sudo rm {} \;
final_size=$(sudo du -s $file_path  | cut -f1)
save_size=initial_size-final_size
save_size=$(bytes_for_humans save_size)
echo "Saved ${save_size}."