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From: Keith Thompson <kst-u@mib.org>
Newsgroups: comp.lang.c
Subject: Re: Why is this outputting alternate blank lines?
Date: Wed, 14 Dec 2016 11:57:43 -0800
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Richard Heathfield <rjh@cpax.org.uk> writes:
> On 14/12/16 17:53, DFS wrote:
[...]
>> Any idea why it crashes above 1 million?
>
> Do you remember when I suggested checking the return value of malloc?
>
> I again suggest that you check the return value of malloc.
>
> The malloc function returns NULL when it fails to allocate memory. Since 
> you're not checking for this, if ever it /does/ return NULL you will be 
> scribbling all over memory you don't own, hence the segfault.

On the other hand, on some systems malloc() generally doesn't report
failure; rather if you allocate too much memory, a crash occurs when you
try to access it.  (This is arguably non-conforming.)

-- 
Keith Thompson (The_Other_Keith) kst-u@mib.org  <http://www.ghoti.net/~kst>
Working, but not speaking, for JetHead Development, Inc.
"We must do something.  This is something.  Therefore, we must do this."
    -- Antony Jay and Jonathan Lynn, "Yes Minister"