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Re: The usage of [[ (not with if)
From: |
Davide Brini |
Subject: |
Re: The usage of [[ (not with if) |
Date: |
Wed, 4 Aug 2010 16:08:05 +0100 |
User-agent: |
KMail/1.13.3 (Linux/2.6.32-gentoo-r10; KDE/4.4.4; x86_64; ; ) |
On Wednesday 04 Aug 2010 16:03:25 Peng Yu wrote:
> I have the following script and output. The man page says "Return a
> status of 0 or 1 depending on the evaluation of the conditional
> expression expression." Therefore, I thought that the two printf
> statements should print 1 and 0 respectively. But both of them print
> 0. I'm wondering what [[ should return if it is not used with a if
> statement.
>
> $ cat main.sh
> #!/usr/bin/env bash
>
> printf '%d\n' `[[ 10 -gt 1 ]]`
> printf '%d\n' `[[ 1 -gt 10 ]]`
> if [[ 10 -gt 1 ]]
> then
> echo xxx
> fi
> $ ./main.sh
> 0
> 0
> xxx
You're confusing "return value of the command" with "output of the command".
--
D.