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Re: Testing Whether $@ Is Empty Or Null
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From: |
Chet Ramey |
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Subject: |
Re: Testing Whether $@ Is Empty Or Null |
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Date: |
Tue, 11 Oct 2022 10:16:21 -0400 |
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User-agent: |
Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:102.0) Gecko/20100101 Thunderbird/102.3.1 |
On 10/11/22 1:00 AM, Jessie Saenz wrote:
bash version = 5.1.16(1)-release
I do not understand why the following statement returns 0 despite no
arguments given to script:
[ -n "$@" ] && echo true
`[' is a builtin, so the arguments undergo word expansion before it's
invoked.
"$@" expands to nothing when there are no positional parameters.
The command ends up being `[ -n ]', which is true because there is one
non-null argument to `['.
--
``The lyf so short, the craft so long to lerne.'' - Chaucer
``Ars longa, vita brevis'' - Hippocrates
Chet Ramey, UTech, CWRU chet@case.edu http://tiswww.cwru.edu/~chet/