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	1	\cfg{man-identity}{base64}{1}{2004-11-20}{Simon Tatham}{Simon Tatham}
	2
	3	\title Man page for \cw{base64}
	4
	5	\U NAME
	6
	7	\cw{base64} - stand-alone encoder and decoder for base64
	8
	9	\U SYNOPSIS
	10
	11	\c base64 [ -d ] [ filename ]
	12	\e bbbbbb bb iiiiiiii
	13	\c base64 -e [ -c width ] [ filename ]
	14	\e bbbbbb bb bb iiiii iiiiiiii
	15
	16	\U DESCRIPTION
	17
	18	\cw{base64} is a command-line utility for encoding and decoding the
	19	\q{base64} encoding.
	20
	21	This encoding, defined in RFC 2045, is primarily used to encode
	22	binary attachments in MIME e-mail, but is widely used in many other
	23	applications as well. For example, the \q{Content-MD5} mail header
	24	contains a small piece of base64; SSH private keys are generally
	25	stored as base64-encoded blobs; and so on.
	26
	27	Other utilities, such as \cw{munpack}, exist which will take an
	28	entire MIME-encoded message, identify the base64-encoded subparts,
	29	and decode them. However, these utilities will not help you if you
	30	need to inspect a Content-MD5 header or an SSH private key.
	31
	32	\cw{base64} is a very simple stand-alone encoder and decoder for the
	33	base64 format \e{alone}. It does not try to understand MIME headers
	34	or anything other than raw data.
	35
	36	\U OPTIONS
	37
	38	By default (if neither \cw{-d} or \cw{-e} is supplied), \cw{base64}
	39	operates in decode mode.
	40
	41	\dt \cw{-d}
	42
	43	\dd Places \cw{base64} into decode mode. In this mode, it will read
	44	from standard input or the supplied file name, ignore all characters
	45	that are not part of the base64 alphabet, decode the ones that are,
	46	and output the decoded data on standard output.
	47
	48	\dt \cw{-e}
	49
	50	\dd Places \cw{base64} into encode mode. In this mode, it will read
	51	binary data from standard input or the supplied file name, encode it
	52	as base64, and output the encoded data on standard output.
	53
	54	\dt \cw{-c} \e{width}
	55
	56	\dd If \cw{base64} is operating in encode mode, this controls the
	57	number of base64 characters output per line of the encoded file.
	58	Normally base64-reading applications do not care about this, so the
	59	default of 64 characters per line is perfectly adequate.
	60
	61	\lcont{
	62
	63	The special value 0 will prevent \cw{base64} from ever writing a
	64	line break in the middle of the data at all.
	65
	66	The base64 encoding converts between a group of three plaintext
	67	bytes and a group of four encoded bytes. \cw{base64} does not
	68	support breaking an encoded group across a line (although it can
	69	handle it as input if it receives it). Therefore, the \e{width}
	70	parameter passed to \cw{-c} must be a multiple of 4.
	71
	72	}
	73
	74	\U LICENCE
	75
	76	\cw{base64} is free software, distributed under the MIT licence.
	77	Type \cw{base64 --licence} to see the full licence text.