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Mail Archives: djgpp/1998/04/29/15:32:45

From: "Lennart Marien" <lennartm AT metronet DOT de>
Newsgroups: comp.os.msdos.djgpp
Subject: malloc?
Date: Wed, 29 Apr 1998 21:27:56 +0200
Organization: Metronet
Lines: 61
Message-ID: <6i7v0o$ns6$1@news.metronet.de>
NNTP-Posting-Host: hamburg1.pop.metronet.de
To: djgpp AT delorie DOT com
DJ-Gateway: from newsgroup comp.os.msdos.djgpp

Hi!
I have a severe problem which is bothering since
hours.What Iīm trying o do is the following in pseudo
code:(the struct PCXHeader is declared before)

int handle;
short width,heigth;
void addr_of_buf;

void readheaderPCX(char *fd,struct PCXHeader *header)
/*this function works*/
{
handle=open(fd,O_BINARY);
 read(handle,header,sizeof(*header));
};

void readln(char *buffer,short width)
{
/*buffer is a pointer to a variable like 'char buffer[width]'*/
[.....]
/*The routine reads data bytes and expands them into buffer
until buffer is full*/
};

void loadpcx(int x, int y, char *fd)
{
struct PCXHeader h;
readheader(fd,&h);
/*works*/
 width=h.x2-h.x1;
  heigth=h.y2-h.y1;
/*donīt know if you understand, but it works*/
addr_of_buf=malloc(width);
[...]
/*the program reads data line and shows it....*/
};


Hope this wasnīt confusing if so here is it in text:
I read some information from an 8Bit-PCX file to compute the height and the
width of
the picture.Then a buffer is allocated to contain one line of a pic.Since
itīs an
8Bit file the variable would look like char buffer[width].
A Pointer addr_of_buf should contain the address of the allocated memory
using malloc:
addr_of_buf=malloc(width);
Now a function called readln reads WIDTH bytes from the file and puts them
into the buffer.My question is actually about malloc hy doesnīt it work?
I always get an error message if I try to address my memory like this:

*addr_of_buf[10]=0;

He tells me of some unary operator *?
What can I do?

Thanks in advance!!!!!
cu



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