Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!csd4.milw.wisc.edu!srcsip!tcnet!nis!pwcs!ncs-med!ecd
From: ecd@ncs-med.UUCP (Elwood C. Downey)
Newsgroups: comp.lang.c
Subject: Re: Indefinite-length array as member of struct:  how?
Summary: "unbounded array" as last member
Keywords: char string [] [0] [1]
Message-ID: <1075@ncs-med.UUCP>
Date: 19 Jul 89 18:31:57 GMT
References: <7360@c3pe.UUCP> <821@fozzy.UUCP> <14465@dartvax.Dartmouth.EDU>
Organization: Dimensional Medicine, Inc.  Minnetonka, MN.
Lines: 17

You might make an array member of length 1 at the end of a struct, then malloc
enough room for all that you really need and index into it via the array.
for example:

struct s {
    ...			/* anything ... */
    char array[1];	/* must be last member */
};

f(n)
int n;
{
	struct s *sp;

	sp = malloc (sizeof(struct s) + n - 1); /* you get 1 already */
	/* now you can use sp->array[0..n-1] */
}