UUDECODE(1POSIX)

✨ PROLOG ✨

okay bestie, before we even get into it — this page is part of the POSIX Programmer's Manual. so like, the Linux version of this interface might be different (if you need the deets on how Linux actually does it, go read the Linux manual page, she's right there), or honestly it might not even be implemented on Linux at all. 💀 no cap.

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🌸 NAME 🌸

uudecode — decode a binary file

it's giving... reverse uno card for uuencode. 🦋

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🎀 SYNOPSIS 🎀

uudecode [-o outfile] [file]

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💖 DESCRIPTION 💖

so uudecode reads a file — or standard input if you didn't hand it a file — and that input has to contain data that was made by the uuencode utility. got it? ✨

then it does its little scan of the input file, searching for data that matches one of the formats specified in uuencode, and it tries to create or overwrite the file described by that data (or overridden by the -o option, if you used that). the pathname lives inside the data, or you specify it with -o. the file access permission bits AND the contents for the file being produced are all contained in that data. 👑

the mode bits of the created file (anything other than standard output) shall be set from the file access permission bits contained in the data — meaning: other attributes of the mode, including the file mode creation mask (see umask), do not affect the file being produced. periodt. and if either of the op characters '+' and '-' (see chmod) show up in symbolic mode, the initial mode that those operations are based on is unspecified. 🙈

if the pathname of the file resolves to an existing file and you do not have write permission on that file, uudecode shall terminate with an error. full stop. 😭 if the pathname resolves to an existing file and you do have write permission, 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 — and if the mode bits can't be set, uudecode shall not treat this as an error. she's forgiving like that. 💅

if the input data was produced by uuencode on a system with a different number of bits per byte than the target system, the results of uudecode are unspecified. like, we don't know her. proceed at your own risk bestie. 💀

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⭐ OPTIONS ⭐

uudecode shall conform to the Base Definitions volume of POSIX.1‐2017, Section 12.2, Utility Syntax Guidelines. she's polite, she follows the rules. 🎀

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. if you specify an outfile option-argument of /dev/stdout, that indicates standard output. yes really. 🫶

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🌈 OPERANDS 🌈

the following operand shall be supported:

• file — the pathname of a file containing the output of uuencode.

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🧚 STDIN 🧚

see the INPUT FILES section. (she's shy, go look over there ⬇️)

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💜 INPUT FILES 💜

the input files shall be files containing the output of uuencode. that's the whole vibe check.

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🌸 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. she overrides. main character energy. 👑
• 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.

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🦋 ASYNCHRONOUS EVENTS 🦋

Default. (nothing dramatic, she's chill ✨)

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🎀 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? standard output shall not be used. like, she's not even gonna look at it. 💅

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💖 STDERR 💖

the standard error shall be used only for diagnostic messages. that's her one job.

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🌈 OUTPUT FILES 🌈

the output file shall be in the same format as the file originally encoded by uuencode. matching set, slay. 🔥

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✨ EXTENDED DESCRIPTION ✨

None. that's it, that's the section, nothing to see here bestie. 🫶

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💅 EXIT STATUS 💅

the following exit values shall be returned:

• 0 — successful completion. 🎉
• >0 — an error occurred. 😭

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🧚 CONSEQUENCES OF ERRORS 🧚

Default.

the following sections are informative.

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⭐ APPLICATION USAGE ⭐

the user who is invoking uudecode must have write permission on any file being created. non-negotiable. 🙅

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. ngl. and of course, the only data that is meaningful for such a transfer between architectures is generally character data. iykyk. 🦋

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🎀 EXAMPLES 🎀

None. (we're not doing examples today, the vibe was enough 💀)

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💜 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. so, yeah. 📬

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. ty WG15, icon behavior. 🫶

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. (we respect the boundary bestie 🚫) 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. 🍪✨

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🌸 FUTURE DIRECTIONS 🌸

None.

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🦋 SEE ALSO 🦋

chmod, umask, uuencode

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

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👑 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 .

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and that's the whole page bestie!! this absolute banger of a manual page was brought to you by IEEE/The Open Group, dated 2017, and she's officially known as UUDECODE(1POSIX) — go decode something, you got this 💖✨🎀🦋