Check if a file exists on Amazon s3 through R on EC2 instance?

Question

I am trying to check if a file exists on s3 through Rstudio on Amazon EC2 instance. Base R's exists() function and file.exists() functions are returning FALSE for every file. Following is my code, exists.type exists in s3 and not_exists.type does not exist.

library("aws.s3")
Sys.setenv("AWS_ACCESS_KEY_ID" = "key1",
           "AWS_SECRET_ACCESS_KEY" = "key2",
           "AWS_DEFAULT_REGION" = "key3"
)

existing_file_path = "s3://bucket_name/folder_name/exists.type"
not_existing_file_path = "s3://bucket_name/folder_name/not_exists.type"

exists(existing_file_path) #returns FALSE
exists(not_existing_file_path) #returns FALSE

file.exists(existing_file_path) returns FALSE
file.exists(not_existing_file_path) returns FALSE

aws.s3::get_object(existing_file_path) #reads the entire file
aws.s3::get_object(not_existing_file_path) #gives error

I tried list.files also, it returns character(0) .

Answer 1

您应该使用函数head_object() ，该函数仅返回有关您对象的元数据，而不返回对象本身。

aws.s3::head_object("your_file", bucket = "your_bucket")