uudecode(1p) — Linux manual page


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

PROLOG         top

       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         top

       uudecode — decode a binary file

SYNOPSIS         top

       uudecode [−o outfile] [file]

DESCRIPTION         top

       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 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

       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         top

       The uudecode utility shall conform to the Base Definitions volume of
       POSIX.1‐2008, 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

OPERANDS         top

       The following operand shall be supported:

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

STDIN         top

       See the INPUT FILES section.

INPUT FILES         top

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


       The following environment variables shall affect the execution of

       LANG      Provide a default value for the internationalization
                 variables that are unset or null. (See the Base Definitions
                 volume of POSIX.1‐2008, Section 8.2, Internationalization
                 Variables for the precedence of internationalization
                 variables used to determine the values of locale

       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

                 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.



STDOUT         top

       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         top

       The standard error shall be used only for diagnostic messages.

OUTPUT FILES         top

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



EXIT STATUS         top

       The following exit values shall be returned:

        0    Successful completion.

       >0    An error occurred.



       The following sections are informative.


       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         top


RATIONALE         top

       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.



SEE ALSO         top

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

       The Base Definitions volume of POSIX.1‐2008, Chapter 8, Environment
       Variables, Section 12.2, Utility Syntax Guidelines

COPYRIGHT         top

       Portions of this text are reprinted and reproduced in electronic form
       from IEEE Std 1003.1, 2013 Edition, Standard for Information
       Technology -- Portable Operating System Interface (POSIX), The Open
       Group Base Specifications Issue 7, Copyright (C) 2013 by the
       Institute of Electrical and Electronics Engineers, Inc and The Open
       Group.  (This is POSIX.1-2008 with the 2013 Technical Corrigendum 1
       applied.) 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.unix.org/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                 2013                        UUDECODE(1P)

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