Add --input-stream option.

[fujiwara]

Add --input-stream option.

refs #6 Thanks for @mattn.

description

--input-stream option allows you to bind a file or stdin to the input struct.

$ aws-sdk-client-go s3 put-object '{"Bucket": "my-bucket", "Key": "my.txt"}' --input-stream my.txt

s3#PutObjectInput has Body field of io.Reader. --input-stream option binds the file to the field.

When the input struct has only one field of io.Reader, aws-sdk-client-go reads the file and binds it to the field automatically. (At now, all SDK input structs have only one field of io.Reader.)

When the input struct has a "*Length" field for the size of the content, aws-sdk-client-go sets the size of the content to the field automatically. For example, s3#PutObjectInput has ContentLength field.

If --input-stream is "-", aws-sdk-client-go reads from stdin. In this case, aws-sdk-client-go reads all contents into memory, so it is not suitable for large files. Consider using a file for large content.