uudecode(1p) — Linux manual page

UUDECODE(1P)            POSIX Programmer's Manual           UUDECODE(1P)

PROLOG

       This manual page is part of the POSIX Programmer's Manual.  The
       Linux implementation of this interface may differ (consult the
       corresponding Linux manual page for details of Linux behavior),
       or the interface may not be implemented on Linux.

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
       either of the op characters '+' and '-' (see chmod) are specified
       in symbolic mode, the initial mode on which those operations are
       based is unspecified.

       If the pathname of the file resolves to an existing file and the
       user does not have write permission on that file, uudecode shall
       terminate with an error. If the pathname of the file resolves to
       an existing file and the user has write permission on that file,
       the existing file shall be overwritten and, if possible, the mode
       bits of the file (other than standard output) shall be set as
       described above; if the mode bits cannot be set, uudecode shall
       not treat this as an error.

       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 POSIX.1‐2017, 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 POSIX.1‐2017, 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 POSIX.1‐2008 as a standard input indicator.  The
       standard developers 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

       chmod(1p), umask(1p), uuencode(1p)

       The Base Definitions volume of POSIX.1‐2017, Chapter 8,
       Environment Variables, Section 12.2, Utility Syntax Guidelines

COPYRIGHT

       Portions of this text are reprinted and reproduced in electronic
       form from IEEE Std 1003.1-2017, Standard for Information
       Technology -- Portable Operating System Interface (POSIX), The
       Open Group Base Specifications Issue 7, 2018 Edition, Copyright
       (C) 2018 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 .

       Any typographical or formatting errors that appear in this page
       are most likely to have been introduced during the conversion of
       the source files to man page format. To report such errors, see
       https://www.kernel.org/doc/man-pages/reporting_bugs.html .

IEEE/The Open Group               2017                      UUDECODE(1P)

Pages that refer to this page: uuencode(1p)

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