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.TH UUDECODE "1P" 2013 "IEEE/The Open Group" "POSIX Programmer's Manual"

.SH 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.

.SH NAME

uudecode

\(em decode a binary file

.SH SYNOPSIS

.LP

.nf

uudecode \fB[\fR\(mio \fIoutfile\fB] [\fIfile\fB]\fR

.fi

.SH DESCRIPTION

The

.IR uudecode

utility shall read a file, or standard input if no file is specified,

that includes data created by the

.IR uuencode

utility. The

.IR uudecode

utility shall scan the input file, searching for data compatible with

one of the formats specified in

.IR uuencode ,

and attempt to create or overwrite the file described by the data (or

overridden by the

.BR \(mio

option). The pathname shall be contained in the data or specified by

the

.BR \(mio

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

.IR umask ),

shall not affect the file being produced. If either of the

.IR op

characters

.BR '\(pl' 

and

.BR '\(mi' 

(see

.IR chmod )

are specified in symbolic mode, the initial mode on which those

operations are based is unspecified.

.P

If the pathname of the file to be produced exists, and the user does

not have write permission on that file,

.IR 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.

.P

If the input data was produced by

.IR uuencode

on a system with a different number of bits per byte than on the target

system, the results of

.IR uudecode

are unspecified.

.SH OPTIONS

The

.IR uudecode

utility shall conform to the Base Definitions volume of POSIX.1\(hy2008,

.IR "Section 12.2" ", " "Utility Syntax Guidelines".

.P

The following option shall be supported by the implementation:

.IP "\fB\(mio\ \fIoutfile\fR" 10

A pathname of a file that shall be used instead of any pathname

contained in the input data. Specifying an

.IR outfile

option-argument of

.BR /dev/stdout

shall indicate standard output.

.SH OPERANDS

The following operand shall be supported:

.IP "\fIfile\fR" 10

The pathname of a file containing the output of

.IR uuencode .

.SH STDIN

See the INPUT FILES section.

.SH "INPUT FILES"

The input files shall be files containing the output of

.IR uuencode .

.SH "ENVIRONMENT VARIABLES"

The following environment variables shall affect the execution of

.IR uudecode :

.IP "\fILANG\fP" 10

Provide a default value for the internationalization variables that are

unset or null. (See the Base Definitions volume of POSIX.1\(hy2008,

.IR "Section 8.2" ", " "Internationalization Variables"

for the precedence of internationalization variables used to determine

the values of locale categories.)

.IP "\fILC_ALL\fP" 10

If set to a non-empty string value, override the values of all the

other internationalization variables.

.IP "\fILC_CTYPE\fP" 10

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).

.IP "\fILC_MESSAGES\fP" 10

.br

Determine the locale that should be used to affect the format and

contents of diagnostic messages written to standard error.

.IP "\fINLSPATH\fP" 10

Determine the location of message catalogs for the processing of

.IR LC_MESSAGES .

.SH "ASYNCHRONOUS EVENTS"

Default.

.SH STDOUT

If the file data header encoded by

.IR uuencode

is

.BR \(mi

or

.BR /dev/stdout ,

or the

.BR \(mio

.BR /dev/stdout

option overrides the file data, the standard output shall be in the

same format as the file originally encoded by

.IR uuencode .

Otherwise, the standard output shall not be used.

.SH STDERR

The standard error shall be used only for diagnostic messages.

.SH "OUTPUT FILES"

The output file shall be in the same format as the file originally

encoded by

.IR uuencode .

.SH "EXTENDED DESCRIPTION"

None.

.SH "EXIT STATUS"

The following exit values shall be returned:

.IP "\00" 6

Successful completion.

.IP >0 6

An error occurred.

.SH "CONSEQUENCES OF ERRORS"

Default.

.LP

.IR "The following sections are informative."

.SH "APPLICATION USAGE"

The user who is invoking

.IR uudecode

must have write permission on any file being created.

.P

The output of

.IR 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.

.SH EXAMPLES

None.

.SH RATIONALE

Input files are not necessarily text files, as stated by an early

proposal. Although the

.IR uuencode

output is a text file, that output could have been wrapped within

another file or mail message that is not a text file.

.P

The

.BR \(mio

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.

.P

In early drafts, the [\c

.BR \(mio

.IR outfile ]

option-argument allowed the use of

.BR \(mi

to mean standard output. The symbol

.BR \(mi

has only been used previously in POSIX.1\(hy2008 as a standard input indicator.

The standard developers did not wish to overload the meaning of

.BR \(mi

in this manner. The

.BR /dev/stdout

concept exists on most modern systems. The

.BR /dev/stdout

syntax does not refer to a new special file. It is just a magic cookie

to specify standard output.

.SH "FUTURE DIRECTIONS"

None.

.SH "SEE ALSO"

.IR "\fIchmod\fR\^",

.IR "\fIumask\fR\^",

.IR "\fIuuencode\fR\^"

.P

The Base Definitions volume of POSIX.1\(hy2008,

.IR "Chapter 8" ", " "Environment Variables",

.IR "Section 12.2" ", " "Utility Syntax Guidelines"

.SH COPYRIGHT

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 .