ascii85
ascii85 is a command-line program for encoding and decoding files using the
Ascii85 algorithm. Ascii85 encodes
groups of four bytes using five printable ASCII characters from a set of 85.
Base64 is a similar algorithm which
encodes three bytes with four characters from a 64-character set, resulting in
more overhead. I based ascii85's command syntax on that of Simon Joseffson's
base64 program from the GNU coreutils.
ascii85 is designed to be flexible in what it can decode. The -i flag will
cause it to skip invalid characters in an encoded file rather than printing an
error message and halting. The <~ and ~> delimiters are also optional; with
the -n flag, all input will be interpreted as Ascii85-encoded data without
looking for delimiters.
When a delimited file is being decoded, ascii85 ignores any characters outside
the delimiters. This means that extra data can be prepended or appended to the
file. For instance, one might want to add checksums or hashes to the end, like
the original btoa program.
Built-in help
NAME
ascii85 - Ascii85 encode/decode data and print to standard output
SYNOPSIS
ascii85 [OPTION]... [FILE]
DESCRIPTION
Ascii85 encode or decode FILE, or standard input, to standard output.
-d, --decode
decode data (encodes by default)
-i, --ignore-garbage
when decoding, ignore invalid characters
-n, --no-delims
when encoding, omit delimiters (<~ and ~>), and when decoding,
do not look for delimiters
-w, --wrap=COLS
wrap encoded lines after COLS characters (default 76). Use 0
to disable line wrapping.
-y, --y-abbr
abbreviates four encoded spaces as 'y'
-h, --help
display this help and exit
With no FILE, or when FILE is -, read standard input.
AUTHOR
Written by Remy Oukaour <remy.oukaour@gmail.com>.
COPYRIGHT
Copyright (C) 2012-2016 Remy Oukaour <http://www.remyoukaour.com>.
MIT License.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.