Re: problems with char * return from a function

[Bob Smith <bsmith at sudleyplace dot com>]

Vardhan, Sundara (GE Infra, Energy) wrote:
> Hi All
>
> I am calling a function x within strcpy as follows
>
> strcpy(a,x("sample text","default text"));
>
> x is defined as follows
>
> char * x(char *m, char *n)
> {
> 	char *return_val=NULL;
> 	if (check m is in database)
> 		return_val=m;
> 	else
> 		return_val=n;
> 	return(return_val);
> }
>  This causes  the array a to have a corrupted string. The string is either m or n but with illegal characters appended.

The function x returns a pointer local to it on the stack which is why 
it is corrupted when its caller gets around to using it.  Instead of 
returning <return_val>, try return m (or n) assuming those values aren't 
also pointers to values local to the function which produces them.
--
_______________________________________________________________
Bob Smith - bsmith@sudleyplace.com - http://www.sudleyplace.com