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Re: Info vs. man of true
From: |
Jim Meyering |
Subject: |
Re: Info vs. man of true |
Date: |
Wed, 07 May 2003 18:28:33 +0200 |
Orna Agmon <address@hidden> wrote:
> On my system, (RH 7.3), I have a man page for true which directs me to the
> updated info page. On the other hand, the info page claims that true does
> not respond to --help and to --version, but it does (as the man page
> claims).
Thanks for the report.
That is fixed in the latest release:
ftp://ftp.gnu.org/gnu/coreutils/coreutils-5.0.tar.bz2
(coreutils is the union of fileutils, textutils, and sh-utils)
The info node for true now tells the truth :-)
`true': Do nothing, successfully
================================
`true' does nothing except return an exit status of 0, meaning
"success". It can be used as a place holder in shell scripts where a
successful command is needed, although the shell built-in command `:'
(colon) may do the same thing faster. In most modern shells, `true' is
a built-in command, so when you use `true' in a script, you're probably
using the built-in command, not the one documented here.
By default, `true' honors the `--help' and `--version' options.
However, that is contrary to POSIX, so when the environment variable
`POSIXLY_CORRECT' is set, `true' ignores _all_ command line arguments,
including `--help' and `--version'.
This version of `true' is implemented as a C program, and is thus
more secure and faster than a shell script implementation, and may
safely be used as a dummy shell for the purpose of disabling accounts.