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Mail Archives: djgpp/1999/12/10/03:40:03

From: Nate Eldredge <neldredge AT hmc DOT edu>
Newsgroups: comp.os.msdos.djgpp
Subject: Re: changing value of pointers
Date: 10 Dec 1999 00:20:10 -0800
Organization: InterWorld Communications
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Steven Watson <steven DOT watson AT dtn DOT ntl DOT com> writes:

> Hi Everyone
> 
> Is it possible someone can tell me how this code can be written to
> change the pointer sent to it
> in pow! using a VAR it will make a copy so the value can be changed but
> I am unable to figure it out in C?
> 
> int  main(void)
> char *string;
>   file_reads(1,5,&string);
>     printf("%s \n",string);
> return 0;
> }
> function from include file:
> 
> void file_reads(int handle,int length,char *dummy)
> {
> 
> 
>      if ((dummy=(char *)malloc(length+1))==NULL){
>         puts("Error code here");
>         exit(1);
>      }
> 
> 
> if((fread(dummy,sizeof(char),length,filehandle[handle]))!=length){
>             puts("Put error code here");
>             exit(1);
>          }
>                 *(dummy+length)=0x00;
>                printf("%s\n",dummy);//it prints here fine as expected.
> return;
> }


void file_reads(int handle, int length, char **dummy)
{
	if ((*dummy = (char *)malloc(length+1)) == NULL)
		/* handle error */
	if (fread(*dummy, blah, blah, blah) != length)
		/* handle error */
	*(*dummy + length) = 0;
}

This question might have been better asked in comp.lang.c, btw.
Actually, I think it's in their FAQ.
-- 

Nate Eldredge
neldredge AT hmc DOT edu

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