uusyntax.man

C语言库函数的源代码,是C语言学习参考的好文档。

+++Date last modified: 05-Jul-1997

            Syntax for SNIPPETS' UUENCODE and UUDECODE utilities
            ----------------------------------------------------


Users not familiar with Unix utilities or filters in general have expressed
some problems using the implementations of UUENCODE and UUDECODE in SNIPPETS.
This file is a quick syntax reference for these implementations.


UUENCODE:
---------

The syntax for this utility may be either...

      UUENCODE [input_file] file_name > uuencoded_file

...or...

      UUENCODE file_name < input_file > uuencoded_file

The UUENCODE utility encodes a binary file using only printable characters to
facilitate transmission of such files (e.g. .ZIP archives) across trans-
mission media designed for the transmission of textual data only. Although
the internal format of the uuencoded file is not important, it does carry
with it both the name of the uuencoded file as well as its encoded data.

The first, optional, argument is the local file name of the file to be
encoded. If the file name is not supplied, the input will be taken from
stdin, i.e. it will act as a true filter (see note below!)

The second, required, argument is the name to use when decoding the file.
This is the name that is stored in the first line of the uuencoded file.

All other arguments are used with the redirection operators, ">" and "<". If
a local file name isn't specified, one must be redirected to stdin using the
"<" operator. The output of uuencode is always to stdout. To send it to a
file rather than appearing on the console, you should use the ">" operator.

NOTE: There is one side effect of this implementation that can cause problems
      in some environments. If the local file name is explicitly specified as
      the optional first argument, everything proceeds as expected. However,
      if the input file is redirected, it may cause unwanted translation of
      newline characters. For example, on my DOS machine, uuencoding a
      redirected text file, then decoding with the SNIPPETS utilities will
      result in the CR/LF pairs terminating each line to be changed to LF
      characters. The solution is to explicitly provide the input file name
      rather than redirecting it.


UUDECODE:
---------

UUDECODE is used to decode a file which has been encoded using the UUENCODE
utility. Its syntax is...

UUDECODE < uuencoded_file

Note that no command line arguments are used and the file to be decoded is
simply redirected to the utility. The decoded output is written directly to a
file whose name is speciified in the first line of the uuencoded file.