PC Extra Super CD 1998 January/PCPLUS131.iso/DJGPP/V2/DJLSR201.ZIP/src/libc/dos/compat/d_read.txh

Text File | 1995-10-09 | 1.3 KB | 49 lines

@node _dos_read, dos
@subheading Syntax

@example
#include <dos.h>

unsigned int _dos_read(int handle, void *buffer, unsigned int count, unsigned int *result);
@end example

@subheading Description

This is a direct connection to the MS-DOS read function call (%ah = 0x3F).
No conversion is done on the data; it is read as raw binary data. This
function reads from @var{handle} into @var{buffer} @var{count} bytes.
@var{count} value may be arbitrary size (for example > 64KB). It puts
number of bytes read into @var{result} if reading is successful.

@xref{_dos_open}. @xref{_dos_creat}. @xref{_dos_creatnew}.
@xref{_dos_write}. @xref{_dos_close}

@subheading Return Value

Returns 0 if successful or DOS error code on error (and sets @var{errno}
to EACCES or EBADF)

@subheading Example

@example
int handle;
unsigned int result;
char *filebuffer;

if ( !_dos_open("FOO.DAT", O_RDONLY, &handle) )
@{
   puts("FOO.DAT openning was successful.");
   if ( (filebuffer = malloc(130000)) != NULL )
   @{
     if ( !_dos_read(handle, buffer, 130000, &result) )
       printf("%u bytes read from FOO.DAT.\n", result);
     else
       puts("Reading error.");
     ...
     /* Do something with filebuffer. */
     ...
   @}
   _dos_close(handle);
@}
@end example