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Groups > comp.lang.c > #89746

Re: Long Question: What might cause the seg fault?

From John Gordon <gordon@panix.com>
Newsgroups comp.lang.c
Subject Re: Long Question: What might cause the seg fault?
Date 2016-06-22 00:25 +0000
Organization PANIX Public Access Internet and UNIX, NYC
Message-ID <nkclts$aod$1@reader1.panix.com> (permalink)
References <nkcdmc$usf$1@dont-email.me> <nkcgea$776$1@dont-email.me>

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In <nkcgea$776$1@dont-email.me> BartC <bc@freeuk.com> writes:

> > float *fw1,*fw2,*fw3,*fk1;
> > int *fxf,*fyf,*fxof,*fyof,*fxm,*fym,*fdelay,*fglen;
> > if (nx==0)    //  nx was init. to 0
> > {
> > if ((fw1 = malloc(nfgraf * sizeof(float))) == NULL)
> >     printf("malloc error\n");

> It seems those pointers (fxm etc) are only initialised when nx is 0; 
> next time, nx is 1 (?), but the pointers will not retain their previous 
> values. Try this:

> static int *fxf,*fyf,*fxof,*fyof,*fxm,*fym,*fdelay,*fglen;

This explains a lot.  I wondered why the heck the mallocs were gated
behind the if...

-- 
John Gordon                   A is for Amy, who fell down the stairs
gordon@panix.com              B is for Basil, assaulted by bears
                                -- Edward Gorey, "The Gashlycrumb Tinies"

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Thread

Long Question: What might cause the seg fault? bilsch <king621@comcast.net> - 2016-06-21 15:04 -0700
  Re: Long Question: What might cause the seg fault? BartC <bc@freeuk.com> - 2016-06-21 23:51 +0100
    Re: Long Question: What might cause the seg fault? BartC <bc@freeuk.com> - 2016-06-21 23:53 +0100
      Re: Long Question: What might cause the seg fault? bilsch <king621@comcast.net> - 2016-06-22 01:55 -0700
    Re: Long Question: What might cause the seg fault? John Gordon <gordon@panix.com> - 2016-06-22 00:25 +0000
  Re: Long Question: What might cause the seg fault? Jerry Stuckle <jstucklex@attglobal.net> - 2016-06-21 19:22 -0400
    Re: Long Question: What might cause the seg fault? John Gordon <gordon@panix.com> - 2016-06-22 00:17 +0000
  Re: Long Question: What might cause the seg fault? "James R. Kuyper" <jameskuyper@verizon.net> - 2016-06-21 19:35 -0400
    Re: Long Question: What might cause the seg fault? bilsch <king621@comcast.net> - 2016-06-22 03:36 -0700
  Re: Long Question: What might cause the seg fault? John Gordon <gordon@panix.com> - 2016-06-22 00:29 +0000
    Re: Long Question: What might cause the seg fault? bilsch <king621@comcast.net> - 2016-06-22 03:38 -0700
  Re: Long Question: What might cause the seg fault? Barry Schwarz <schwarzb@dqel.com> - 2016-06-21 21:20 -0700

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