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Re: [bug-gawk] How to test if a variable is uninitialized or is just a v
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From: |
Aharon Robbins |
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Subject: |
Re: [bug-gawk] How to test if a variable is uninitialized or is just a variable that happens to be an empty string? |
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Date: |
Wed, 17 Oct 2012 23:12:51 +0200 |
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User-agent: |
Heirloom mailx 12.5 6/20/10 |
Greetings. Re this:
> Date: Mon, 8 Oct 2012 20:43:57 -0500
> From: Peng Yu <address@hidden>
> To: address@hidden
> Subject: [bug-gawk] How to test if a variable is uninitialized or is just a
> variable that happens to be an empty string?
>
> Hi,
>
> I'm not able to find a function to test if a variable is uninitialized
> or is just a variable that happens to be an empty string in the
> manual. Is there such a function in awk? Thanks!
You can use
if (x == 0 && x == "")
to test if `x' is uninitialized. The condition will be true only if so.
Thanks,
Arnold