rename files within a directory one by one, using for loop and mv

for f in dir/*; do
    mv -- "$f" "$fSuffix" 
done 

So all the files in the dir/ will be renamed:

file1.txt --> file1.txtSuffix

file2.png --> file2.pngSuffix

Copy s3 files selected by dates

 $ aws s3 ls s3://<bucket-name> --recursive | awk '/^2018-11-06/{system("aws s3 cp s3://<bucket-name>/$4 .") }'