如何使用 .NET AWS SDK 在从 AWS S3 检索时过滤、模式匹配文件？

Question

When using the ListObjects request (.NET AWS SDK), is there a way to only list files where the key matches a given pattern? Or, more broadly, is there a way to query files from S3 based on their key using any request type from the .NET AWS SDK?

I'm aware of the --query param, available on AWS CLI , but I'm not able to find an equivalent method on .NET.

I'm looking for a way to run the query server-side so that ListObjects returns a pattern-matching set of keys. I'd like to avoid retrieving all files and then filter them.

Answer 1

The AWS CLI uses JMESPath for query expressions. There is a .NET port called JmesPath.NET that is compatible with the same API and is well-maintained. You could use the SDK to retrieve the result set, and then filter it with JmesPath.NET expressions. It's available as a NuGet package too.

The --query param on the CLI filters the result set on output, similar to what would happen with JmesPath.NET. It doesn't affect what the API call returns. The only request parameters available to reduce the result set are prefix and delimiter , which group things logically like a folder structure does in a file storage engine. Unless your use case can be handled by those parameters, you're stuck with filtering on the output side.