NAME

       uudecode - decode a binary file

SYNOPSIS

       uudecode [-o outfile][file]

DESCRIPTION

       The  uudecode  utility  shall read a file, or standard input if no file is specified, that
       includes data created by the uuencode utility. The uudecode utility shall scan  the  input
       file,  searching  for  data  compatible with one of the formats specified in uuencode, and
       attempt to create or overwrite the file described by the data (or  overridden  by  the  -o
       option).  The  pathname  shall be contained in the data or specified by the -o option. The
       file access permission bits and contents for the file to be produced shall be contained in
       that  data.  The  mode  bits of the created file (other than standard output) shall be set
       from the file access permission bits contained in the data; that is, other  attributes  of
       the  mode, including the file mode creation mask (see umask() ), shall not affect the file
       being produced.

       If the pathname of the file to be produced exists,  and  the  user  does  not  have  write
       permission  on  that  file, uudecode shall terminate with an error. If the pathname of the
       file to be produced exists, and the user has write permission on that file,  the  existing
       file shall be overwritten.

       If the input data was produced by uuencode on a system with a different number of bits per
       byte than on the target system, the results of uudecode are unspecified.

OPTIONS

       The uudecode utility shall conform to the Base Definitions volume of IEEE Std 1003.1-2001,
       Section 12.2, Utility Syntax Guidelines.

       The following option shall be supported by the implementation:

       -o  outfile
              A  pathname  of  a file that shall be used instead of any pathname contained in the
              input data. Specifying an outfile option-argument  of  /dev/stdout  shall  indicate
              standard output.

OPERANDS

       The following operand shall be supported:

       file   The pathname of a file containing the output of uuencode.

STDIN

       See the INPUT FILES section.

INPUT FILES

       The input files shall be files containing the output of uuencode.

ENVIRONMENT VARIABLES

       The following environment variables shall affect the execution of uudecode:

       LANG   Provide  a  default  value for the internationalization variables that are unset or
              null. (See the  Base  Definitions  volume  of  IEEE Std 1003.1-2001,  Section  8.2,
              Internationalization Variables for the precedence of internationalization variables
              used to determine the values of locale categories.)

       LC_ALL If set to  a  non-empty  string  value,  override  the  values  of  all  the  other
              internationalization variables.

       LC_CTYPE
              Determine  the  locale for the interpretation of sequences of bytes of text data as
              characters (for  example,  single-byte  as  opposed  to  multi-byte  characters  in
              arguments and input files).

       LC_MESSAGES
              Determine  the  locale  that  should  be  used to affect the format and contents of
              diagnostic messages written to standard error.

       NLSPATH
              Determine the location of message catalogs for the processing of LC_MESSAGES .

ASYNCHRONOUS EVENTS

       Default.

STDOUT

       If the file data header encoded by uuencode is - or /dev/stdout,  or  the  -o  /dev/stdout
       option  overrides  the  file  data, the standard output shall be in the same format as the
       file originally encoded by uuencode. Otherwise, the standard output shall not be used.

STDERR

       The standard error shall be used only for diagnostic messages.

OUTPUT FILES

       The output file shall be in the same format as the file originally encoded by uuencode.

EXTENDED DESCRIPTION

       None.

EXIT STATUS

       The following exit values shall be returned:

        0     Successful completion.

       >0     An error occurred.

CONSEQUENCES OF ERRORS

       Default.

       The following sections are informative.

APPLICATION USAGE

       The user who is invoking uudecode must have write permission on any file being created.

       The output of uuencode is essentially an encoded bit stream that is not cognizant of  byte
       boundaries.  It  is  possible  that  a 9-bit byte target machine can process input from an
       8-bit source, if it is aware of the  requirement,  but  the  reverse  is  unlikely  to  be
       satisfying.   Of  course,  the  only  data  that is meaningful for such a transfer between
       architectures is generally character data.

EXAMPLES

       None.

RATIONALE

       Input files are not necessarily text files, as stated by an early proposal.  Although  the
       uuencode output is a text file, that output could have been wrapped within another file or
       mail message that is not a text file.

       The -o option is not historical practice, but was added at the request of WG15 so that the
       user could override the target pathname without having to edit the input data itself.

       In  early  drafts, the [ -o outfile] option-argument allowed the use of - to mean standard
       output. The symbol - has only been used previously in IEEE Std 1003.1-2001 as  a  standard
       input  indicator. The developers of the standard did not wish to overload the meaning of -
       in this manner.  The /dev/stdout concept exists on most modern  systems.  The  /dev/stdout
       syntax does not refer to a new special file. It is just a magic cookie to specify standard
       output.

FUTURE DIRECTIONS

       None.

SEE ALSO

       umask() , uuencode

COPYRIGHT

       Portions of this text are reprinted and  reproduced  in  electronic  form  from  IEEE  Std
       1003.1,  2003  Edition,  Standard  for Information Technology -- Portable Operating System
       Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2003  by
       the  Institute  of  Electrical  and  Electronics Engineers, Inc and The Open Group. In the
       event of any discrepancy between this version and the original IEEE  and  The  Open  Group
       Standard,  the  original  IEEE  and  The  Open Group Standard is the referee document. The
       original Standard can be obtained online at http://www.opengroup.org/unix/online.html .