COLON(1POSIX)

📦 version 2017a, in debian bookworm, debian trixie, ubuntu jammy, ubuntu noble, ubuntu resolute, ubuntu stonking

💅 COLON(1POSIX) — the null utility, but make it iconic 💅

okay bestie, sit down, hydrate, because we're about to talk about the most lowkey powerful little nothing in the whole shell. this page is straight out of the POSIX Programmer's Manual (the Linux version of this interface might act different — check the matching Linux man page if you're curious, or it might not even be implemented on Linux at all, no cap).

🧚 PROLOG 🧚

so like, real talk: 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. heads up bestie 💖

✨ NAME ✨

colon — null utility she does nothing and she does it flawlessly 👑

🎀 SYNOPSIS 🎀

: [argument...]

🦋 DESCRIPTION 🦋

This utility shall only expand command arguments. It is used when a command is needed, as in the then condition of an if command, but nothing is to be done by the command.

literally the "i'm here, i'm present, i'm doing nothing" of the shell world. main character energy with zero plot. obsessed. 💅

🌸 OPTIONS 🌸

None. not a single flag, not one, she's minimal like that ✨

💜 OPERANDS 💜

See the DESCRIPTION. (yes bestie, go look up there 👆)

🍓 STDIN 🍓

Not used.

🌈 INPUT FILES 🌈

None.

🫶 ENVIRONMENT VARIABLES 🫶

None.

⭐ ASYNCHRONOUS EVENTS ⭐

Default.

🧁 STDOUT 🧁

Not used.

💀 STDERR 💀

The standard error shall be used only for diagnostic messages.

🎁 OUTPUT FILES 🎁

None.

🔥 EXTENDED DESCRIPTION 🔥

None.

👑 EXIT STATUS 👑

Zero. always zero, always thriving, never stressed 💅

🌸 CONSEQUENCES OF ERRORS 🌸

Default.

The following sections are informative.

🦋 APPLICATION USAGE 🦋

None.

✨ EXAMPLES ✨

okay bestie here's the vibe:

: ${X=abc}
if     false
then   :
else   echo $X
fi
abc

As with any of the special built-ins, the null utility can also have variable assignments and redirections associated with it, such as:

x=y : > z

which sets variable x to the value y (so that it persists after the null utility completes) and creates or truncates file z.

not me realizing : can set variables AND truncate files in one line 😭 she's multi-talented fr fr

🧚 RATIONALE 🧚

None.

💖 FUTURE DIRECTIONS 💖

None.

🌈 SEE ALSO 🌈

  • Section 2.14, Special Built-In Utilities

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 .

and that's the whole page bestie 🫶 brought to you by IEEE/The Open Group, 2017 — mwah, ty for the lore, periodt 💅✨

📦 where this page comes from