base64 - encode and decode to base64
$ base64 [--decode] [--wrap column] [file]
base64 encodes or decodes to base64 the data in file file or from stdin if file is not specified or file is -.
-d, --decode: Decode data-w column, --wrap column: When encoding, wrap output after column characters# base64 encode the text 'A'
$ echo 'A' | base64
# base64 encode the content of hi.txt
$ base64 hi.txt
# base64 encode the content of baz.txt and wrap after 4 columns
$ base64 -w 4 baz.txt
# base64 decode the text 'Zm9v'
$ echo 'Zm9v' | base64 -d
# base64 decode the content of foo.txt
$ base64 -d foo.txt