Table des matières
INT 0x21 - 0x40 - Write To File or Device Using Handle
Request/Call:
| reg | value | descr |
|---|---|---|
| AH | 0x40 | |
| BX | File Handle | |
| CX | number of bytes to write, a zero value truncates/extends the file to the current file position | |
| DS:DX | pointer to data buffer to write |
Return:
CF cleared : success
| reg | descr |
|---|---|
| AX | number of written bytes |
CF Set: error
| reg | descr |
|---|---|
| AX | error code (see (see DOS Error Code)) |
Notes & Comments
- if AX is not equal to CX on return, a partial write occurred
- this function can be used to truncate a file to the current file position by writing zero bytes