TRUE(1) General Commands Manual TRUE(1)

true, falsedo nothing

true
false

Ignored.

true:
(success)
false:

The : sh(1) built-in, equivalent to true.

Conforms to IEEE Std 1003.1-2008 (“POSIX.1”), though the standard allows false to exit with any non-0 value.

Appeared in Version 7 AT&T UNIX as

true, false - provide truth values
with true an empty file and false reading
exit 1

AT&T System III UNIX false exits . Later releases retain these implementations, with increasing amounts of licensing and licence comments; AT&T System V Release 4 UNIX adds /sbin/sh shebangs.

X/Open Portability Guide Issue 2 (“XPG2”) standardises true as exiting "zero" and false — "non-zero", as present-day.

July 23, 2022 voreutils pre-v0.0.0-latest