static void interpret_pipe(struct interpreter_context *context, struct ast_node *node)
{
struct gsh_command *cmd1 = node->n_children;
struct gsh_command *cmd2 = node->n_children->next;
int in = sys_fcntl(0, 0, 0, 0);
int out = sys_fcntl(1, 0, 0, 0);
int err = sys_fcntl(2, 0, 0, 0);
int pipe_des[2];
sys_pipe(pipe_des);
close(0);
sys_fcntl(pipe_des[0], 0, 0, 0);
int pid = interpret_cmd(context, cmd2, P_NOWAIT);
close(0);
close(1);
close(2);
sys_fcntl(in, 0, 0, 0);
sys_fcntl(pipe_des[1], 0, 1, 0);
sys_fcntl(pipe_des[1], 0, 2, 0);
interpret_cmd(context, cmd1, P_WAIT);
close(1);
close(2);
sys_fcntl(out, 0, 1, 0);
sys_fcntl(err, 0, 2, 0);
close(pipe_des[0]);
close(pipe_des[1]);
int status;
sys_waitpid(pid, &status);
close(out);
close(err);
}
static void interpret_node(struct interpreter_context *context, struct ast_node *node)
{
switch(node->n_type) {
case NODE_CMD:
interpret_cmd(context, (struct gsh_command*)node, P_WAIT);
break;
case NODE_RDIR:
interpret_rdir(context, node);
break;
case NODE_PIPE:
interpret_pipe(context, node);
break;
}
}
static void interpret_rdir(struct interpreter_context *context, struct ast_node *node)
{
struct gsh_command *file = node->n_children->next;
int f = sys_open(file->c_args[0], O_WRONLY | O_CREAT);
int out = sys_fcntl(1, 0, 0, 0);
int err = sys_fcntl(2, 0, 0, 0);
close(1);
close(2);
sys_fcntl(f, 0, 1, 0);
sys_fcntl(f, 0, 2, 0);
interpret_cmd(context, node->n_children, P_WAIT);
close(f);
close(1);
close(2);
sys_fcntl(out, 0, 1, 0);
sys_fcntl(err, 0, 2, 0);
close(out);
close(err);
}
int main()
{
enableInterrupts();
while(1) {
clear_scr();
dino_print("Welcome to dinoDOS. Please login.\n\0");
while(!validate()) {
dino_print("Error: invalid credentials.\n\0");
}
//we do not want to logout yet
logout = FALSE;
clear_scr();
//begin the shell promt
while(!logout) {
//holds the current input
char curInput[MAX_INPUT];
//used to print or not print a new line after a command
bool addNewLine;
//print the prompt
dino_print(prompt);
//wait for input
read_input(curInput, MAX_INPUT);
//only run on non-empty inputs
if (strlen(curInput) > 0) {
//return tells if a line break should be printed
addNewLine = interpret_cmd(curInput);
} else {
//we want to add a new line if it was empty
addNewLine = TRUE;
}
//print the new line if we want it
if (addNewLine) {
dino_print("\n\0");
}
//let the another process continue
yield();
//on to the next command!
}
}
}
