BTOA(1) UNIX 5.0 (local) BTOA(1)
NAME
btoa, atob, tarmail, untarmail - encode/decode binary to
printable ASCII
SYNOPSIS
btoa
atob
tarmail who subject files ...
untarmail [ file ]
DESCRIPTION
Btoa is a filter that reads anything from the standard
input, and encodes it into printable ASCII on the standard
output. It also attaches a header and checksum information
used by the reverse filter atob to find the start of the
data and to check integrity.
Atob reads an encoded file, strips off any leading and
trailing lines added by mailers, and recreates a copy of the
original file on the standard output. Atob gives NO output
(and exits with an error message) if its input is garbage or
the checksums do not check.
Tarmail is a shell script that tar's up all the given files,
pipes them through compress, btoa, and mails them to the
given person with the given subject phrase. For example:
tarmail ralph "here it is ralph" foo.c a.out
Will package up files "foo.c" and "a.out" and mail them to
"ralph" using subject "here it is ralph". Notice the quotes
on the subject. They are necessary to make it one argument
to the shell.
Tarmail with no args will print a short message reminding
you what the required args are. When the mail is received
at the other end, that person should use mail to save the
message in some temporary file name (say "xx"). Then saying
"untarmail xx" will decode the message and untar it.
Untarmail can also be used as a filter. By using tarmail,
binary files and entire directory structures can be easily
transmitted between machines. Naturally, you should
understand what tar itself does before you use tarmail.
Other uses:
compress < secrets | crypt | btoa | mail ralph
will mail the encrypted contents of the file "secrets" to
ralph. If ralph knows the encryption key, he can decode it
by saving the mail (say in "xx"), and then running:
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BTOA(1) UNIX 5.0 (local) BTOA(1)
atob < xx | crypt | uncompress
(crypt requests the key from the terminal, and the "secrets"
come out on the terminal).
AUTHOR
Paul Rutter (modified by Joe Orost)
FEATURES
Btoa uses a compact base-85 encoding so that 4 bytes are
encoded into 5 characters (file is expanded by 25%). As a
special case, 32-bit zero is encoded as one character. This
encoding produces less output than uuencode(1).
SEE ALSO
compress(1), crypt(1), uuencode(1), mail(1)
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