1UUDECODE(1P) POSIX Programmer's Manual UUDECODE(1P)
2
6 This manual page is part of the POSIX Programmer's Manual. The Linux
7 implementation of this interface may differ (consult the corresponding
8 Linux manual page for details of Linux behavior), or the interface may
9 not be implemented on Linux.
10
12 uudecode — decode a binary file
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15 uudecode [-o outfile] [file]
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18 The uudecode utility shall read a file, or standard input if no file is
19 specified, that includes data created by the uuencode utility. The
20 uudecode utility shall scan the input file, searching for data compati‐
21 ble with one of the formats specified in uuencode, and attempt to cre‐
22 ate or overwrite the file described by the data (or overridden by the
23 -o option). The pathname shall be contained in the data or specified by
24 the -o option. The file access permission bits and contents for the
25 file to be produced shall be contained in that data. The mode bits of
26 the created file (other than standard output) shall be set from the
27 file access permission bits contained in the data; that is, other
28 attributes of the mode, including the file mode creation mask (see
29 umask), shall not affect the file being produced. If either of the op
30 characters '+' and '-' (see chmod) are specified in symbolic mode, the
31 initial mode on which those operations are based is unspecified.
32 If the pathname of the file resolves to an existing file and the user
34 does not have write permission on that file, uudecode shall terminate
35 with an error. If the pathname of the file resolves to an existing file
36 and the user has write permission on that file, the existing file shall
37 be overwritten and, if possible, the mode bits of the file (other than
38 standard output) shall be set as described above; if the mode bits can‐
39 not be set, uudecode shall not treat this as an error.
40 If the input data was produced by uuencode on a system with a different
42 number of bits per byte than on the target system, the results of uude‐
43 code are unspecified.
44
46 The uudecode utility shall conform to the Base Definitions volume of
47 POSIX.1‐2017, Section 12.2, Utility Syntax Guidelines.
48 The following option shall be supported by the implementation:
50 -o outfile
52 A pathname of a file that shall be used instead of any path‐
53 name contained in the input data. Specifying an outfile
54 option-argument of /dev/stdout shall indicate standard out‐
55 put.
56
58 The following operand shall be supported:
59 file The pathname of a file containing the output of uuencode.
61
63 See the INPUT FILES section.
64
66 The input files shall be files containing the output of uuencode.
67
69 The following environment variables shall affect the execution of uude‐
70 code:
71 LANG Provide a default value for the internationalization vari‐
73 ables that are unset or null. (See the Base Definitions vol‐
74 ume of POSIX.1‐2017, Section 8.2, Internationalization Vari‐
75 ables for the precedence of internationalization variables
76 used to determine the values of locale categories.)
77 LC_ALL If set to a non-empty string value, override the values of
79 all the other internationalization variables.
80 LC_CTYPE Determine the locale for the interpretation of sequences of
82 bytes of text data as characters (for example, single-byte as
83 opposed to multi-byte characters in arguments and input
84 files).
85 LC_MESSAGES
87 Determine the locale that should be used to affect the format
88 and contents of diagnostic messages written to standard
89 error.
90 NLSPATH Determine the location of message catalogs for the processing
92 of LC_MESSAGES.
93
95 Default.
96
98 If the file data header encoded by uuencode is - or /dev/stdout, or the
99 -o /dev/stdout option overrides the file data, the standard output
100 shall be in the same format as the file originally encoded by uuencode.
101 Otherwise, the standard output shall not be used.
102
104 The standard error shall be used only for diagnostic messages.
105
107 The output file shall be in the same format as the file originally
108 encoded by uuencode.
109
111 None.
112
114 The following exit values shall be returned:
115 0 Successful completion.
117 >0 An error occurred.
119
121 Default.
122 The following sections are informative.
124
126 The user who is invoking uudecode must have write permission on any
127 file being created.
128 The output of uuencode is essentially an encoded bit stream that is not
130 cognizant of byte boundaries. It is possible that a 9-bit byte target
131 machine can process input from an 8-bit source, if it is aware of the
132 requirement, but the reverse is unlikely to be satisfying. Of course,
133 the only data that is meaningful for such a transfer between architec‐
134 tures is generally character data.
135
137 None.
138
140 Input files are not necessarily text files, as stated by an early pro‐
141 posal. Although the uuencode output is a text file, that output could
142 have been wrapped within another file or mail message that is not a
143 text file.
144 The -o option is not historical practice, but was added at the request
146 of WG15 so that the user could override the target pathname without
147 having to edit the input data itself.
148 In early drafts, the [-o outfile] option-argument allowed the use of -
150 to mean standard output. The symbol - has only been used previously in
151 POSIX.1‐2008 as a standard input indicator. The standard developers
152 did not wish to overload the meaning of - in this manner. The /dev/std‐
153 out concept exists on most modern systems. The /dev/stdout syntax does
154 not refer to a new special file. It is just a magic cookie to specify
155 standard output.
156
158 None.
159
161 chmod, umask, uuencode
162 The Base Definitions volume of POSIX.1‐2017, Chapter 8, Environment
164 Variables, Section 12.2, Utility Syntax Guidelines
165
167 Portions of this text are reprinted and reproduced in electronic form
168 from IEEE Std 1003.1-2017, Standard for Information Technology -- Por‐
169 table Operating System Interface (POSIX), The Open Group Base Specifi‐
170 cations Issue 7, 2018 Edition, Copyright (C) 2018 by the Institute of
171 Electrical and Electronics Engineers, Inc and The Open Group. In the
172 event of any discrepancy between this version and the original IEEE and
173 The Open Group Standard, the original IEEE and The Open Group Standard
174 is the referee document. The original Standard can be obtained online
175 at http://www.opengroup.org/unix/online.html .
176 Any typographical or formatting errors that appear in this page are
178 most likely to have been introduced during the conversion of the source
179 files to man page format. To report such errors, see https://www.ker‐
180 nel.org/doc/man-pages/reporting_bugs.html .
181IEEE/The Open Group 2017 UUDECODE(1P)