3-53
3F Read file
Copy (CX) bytes from current address to DS:DX.
Advance the current address (CX) number of bytes.
Entry Parameters: AH = 3F
BX = file handle
CX = number of bytes to read
DS:DX = segment:offset of buffer area
Returned Values: if successful: Carry = clear,
AX = number of bytes read, 0 if EOF
if fail: Carry = set, AX = 6
int TS_read_file(int hdl,int cnt,char *str)
{
segregs.ds = FP_SEG(str);
regs.x.dx = FP_OFF(str);
regs.h.ah=0x3f;
regs.x.cx=cnt;
regs.x.bx=hdl;
int86x(0x21,®s,®s,&segregs);
if ((regs.x.cflag & 0x01) == 0) return(regs.x.ax);
else return(-1);
}
40 Write file
Copy (CX) bytes from DS:DX to file (BX). Update BX current address and
ending address. If CX is assigned with 0 (zero), the system will truncate the
file from the current file pointer position. This function can be used by MSC
function call chsize().
Entry Parameters: AH = 40
BX = file handle
CX = number of bytes to write or 0
DS:DX = segment:offset of buffer area
Returned Values: if successful: Carry = clear,
AX = number of bytes read, 0 if full
if fail: Carry = set, AX = 6
int TS_write_file(int hdl,int cnt,char *str)
{
segregs.ds = FP_SEG(str);
regs.x.dx = FP_OFF(str);
regs.h.ah=0x40;
regs.x.bx=hdl;
regs.x.cx=cnt;
int86x(0x21,®s,®s,&segregs);