deleteFoldersCountMoreThen200.sh

#!/bin/bash

# This script deletes the oldest folders matching a specified pattern in a given directory while ensuring 
# at least 200 folders remain. It sorts all matching directories by modification time, oldest first, 
# calculates how many to delete if there are more than 200, and then removes the excess oldest folders. 
# This can be useful for maintaining space or managing backups. 
# Additionally, this script uses a lock file to prevent concurrent execution.


# Folder pattern to match
folder_pattern="oplog.rs_data_till"


# Directory where to look for folders (using current directory by default)
target_dir="/mongo-oplog-dump/data/"

# Minimum number of folders to keep
min_folders_to_keep=200

# Get all directories matching the pattern, sorted by modification time (oldest first)
folders=($(find "$target_dir" -maxdepth 1 -type d -name "$folder_pattern*" ! -path "$target_dir" -printf '%T@ %p\n' | sort -n | awk '{print $2}'))

# Count the number of folders
folder_count=${#folders[@]}

# If we have more than the minimum number of folders, delete the excess
if [ "$folder_count" -gt "$min_folders_to_keep" ]; then
    # Calculate how many folders to delete
    folders_to_delete=$((folder_count - min_folders_to_keep))
    
    echo "Deleting oldest $folders_to_delete folders matching $folder_pattern:"
    
    # Loop through the array from the beginning to delete oldest folders
    for (( i=0; i<folders_to_delete; i++ )); do
        echo "Removing ${folders[i]}"
        rm -rf "${folders[i]}"
    done
else
    echo "Not enough folders matching $folder_pattern to delete. Current count: $folder_count"
fi