/**
* Returns number of arguments within a string.
*
* @param arg_str string with arguments, seperated with ','
* @return number of arguments
*/
unsigned int
get_args_count(const char *arg_str)
{
unsigned int count = 1;
while ((arg_str = get_arg_ptr(arg_str, 1)) != 0)
++count;
return count;
}
/**
* Copy the n'th argument within a string into a buffer in respect
* to a limited buffer size
*
* @param arg_str string with arguments, seperated with ','
* @param index index of the requested arguments whithin arg_str
* @param buffer pointer to the buffer
* @param length size of the buffer
* @return pointer of buffer on success
* NULL if index is out of range.
*/
char *
argncpy(const char *arg_str, unsigned int index, char *buffer,
unsigned int length)
{
const char *ptr = get_arg_ptr(arg_str, index);
unsigned int len;
if (!ptr)
return 0;
len = get_arg_length(ptr);
if (!strncpy(buffer, ptr, length))
return 0;
buffer[len] = 0;
return buffer;
}
static void
syscall_handler (struct intr_frame *f)
{
int *sys_call;
int *status;
int *fd;
const char **buf;
int *size;
const char **file;
tid_t *pid;
const char **cmd_line;
unsigned *initial_size;
unsigned *position;
void **buffer;
sys_call = (int*) f->esp;
check_ptr(sys_call);
switch(*sys_call) {
case SYS_HALT:
sys_halt ();
break;
case SYS_EXIT:
status = (int *) get_arg_ptr (f->esp, 1);
sys_exit(*status);
NOT_REACHED();
break;
case SYS_EXEC:
cmd_line = (const char **) get_arg_ptr (f->esp, 1);
f->eax = sys_exec (*cmd_line);
break;
case SYS_WAIT:
pid = (tid_t *) get_arg_ptr (f->esp, 1);
f->eax = sys_wait (*pid);
break;
case SYS_CREATE:
file = (const char **) get_arg_ptr (f->esp, 1);
initial_size = (unsigned *) get_arg_ptr (f->esp, 2);
f->eax = sys_create (*file, *initial_size);
break;
case SYS_REMOVE:
file = (const char **) get_arg_ptr (f->esp, 1);
f->eax = sys_remove (*file);
break;
case SYS_OPEN:
file = (const char **) get_arg_ptr(f->esp, 1);
f->eax = sys_open (*file);
break;
case SYS_FILESIZE:
fd = (int *) get_arg_ptr (f->esp, 1);
f->eax = sys_filesize (*fd);
break;
case SYS_READ:
fd = (int *) get_arg_ptr (f->esp, 1);
buffer = (void **) get_arg_ptr (f->esp, 2);
size = (int *) get_arg_ptr (f->esp, 3);
f->eax = sys_read (*fd, *buffer, *size);
break;
case SYS_WRITE:
fd = (int *) get_arg_ptr (f->esp, 1);
buf = (const void **) get_arg_ptr (f->esp, 2);
size = (int *) get_arg_ptr (f->esp, 3);
f->eax = sys_write (*fd, *buf, *size);
break;
case SYS_SEEK:
fd = (int *) get_arg_ptr (f->esp, 1);
position = (unsigned *) get_arg_ptr (f->esp, 2);
sys_seek (*fd, *position);
break;
case SYS_TELL:
fd = (int *) get_arg_ptr (f->esp, 1);
f->eax = sys_tell (*fd);
break;
case SYS_CLOSE:
fd = (int *) get_arg_ptr (f->esp, 1);
sys_close (*fd);
break;
default:
printf ("Unrecognized system call!\n");
thread_exit ();
}
}
