Af first you need to install AWS Command Line Interface https://aws.amazon.com/cli/
and configure using AWS Access Key ID & AWS Secret Access Key from your AWS console https://console.aws.amazon.com
Lets the s3 bucket name
To see the list of all files in the bucket with the command in the terminal.
aws s3 ls s3://codeshikari.com
Now copy a local file to the bucket with the command in the terminal
aws s3 cp test.txt s3://codeshikari.com
Also, you can copy the file from the bucket using this command
aws s3 cp s3://codeshikari.com/test.txt ./
And can remove a file from the bucket using this command.
aws s3 rm s3://codeshikari.com/test.txt