How can you verify that the uploaded file matches the selected or expected one?

To verify that the uploaded file matches the selected or expected one, several approaches can be used:

1. Checksum verification (hash sum) — calculate the hash (e.g., MD5, SHA-256) of the original file and the uploaded one, then compare them. If they match, the file has not changed.

2. Compare file sizes — a simple but less reliable method.

3. Content verification — if the file is text, you can compare the content line by line.

4. Use of metadata — for example, compare creation date, file type, name.

Example in Bash for hash verification:

original_hash=$(sha256sum original_file.txt | awk '{print $1}')
uploaded_hash=$(sha256sum uploaded_file.txt | awk '{print $1}')

if [ "$original_hash" = "$uploaded_hash" ]; then
    echo "Files match"
else
    echo "Files differ"
fi

In DevOps processes, such verification is often automated in scripts after file uploads to ensure data integrity and correctness.