int run_cmd(int argc, char *argv[])
{
char last_bg_pid[50], msg[50];
if (argv[0] == NULL) {
/* ignore the blank line. */
return 1;
} else if (strcmp(argv[0], "quit") == 0) {
/* quit the shell. */
if (argv[1] != NULL) {
if (!isalpha(*argv[1])){
cmd_exit_status = atoi(argv[1]);
}
}
exit_status = cmd_exit_status;
return 0;
} else if (strcmp(argv[0], "echo") == 0) {
/* echo: print all the words after the echo command. */
cmd_exit_status = echo(argc, argv);
} else if ((strcmp(argv[0], "cd") == 0) || (strcmp(argv[0], "chdir") == 0)) {
/* change the working directory.*/
cmd_exit_status = changeDirectory(argc, argv);
} else if (strcmp(argv[0], "set") == 0) {
/* Set variable by the given value.*/
cmd_exit_status = setVariable(argc, argv);
} else if (strcmp(argv[0], "wait") == 0) {
if (argv[1] == NULL) {
printf("wait <PID>\n");
cmd_exit_status = 1;
} else {
cmd_exit_status = wait_cmd((pid_t) atoi(argv[1]));
}
} else if (strcmp(argv[0], "unset") == 0) {
/* do unset */
cmd_exit_status = unset_cmd(argc, argv);
} else {
/* Command not found. Look for external command to run. */
cmd_exit_status = run_external_cmd(argv);
}
sprintf(msg, "Command exited with exit status %d", cmd_exit_status);
debug(msg);
sprintf(last_bg_pid, "%d", background_pid);
setenv("!", last_bg_pid, 1);
return 1;
}
bg_task launch_background_cmd(int task_id, std::vector<std::string> args)
{
timeval t;
gettimeofday(&t, nullptr);
int pipefd[2];
if (0 == pipe(pipefd))
{
pid_t watcher_pid = fork();
switch (watcher_pid)
{
case -1: // Error
{
std::cerr << "Error on fork(): " << strerror(errno) << "\n";
return bg_task{-2, process_info{-1, t}, process_info{}};
} break;
case 0: // Child process
{
close(pipefd[0]); // Close read end
auto info = launch_cmd(args);
write(pipefd[1], &info, sizeof(process_info));
wait_cmd(info);
std::exit(EXIT_SUCCESS);
} break;
default: // Parent process
{
close(pipefd[1]); // Close write end
process_info info;
read(pipefd[0], &info, sizeof(process_info));
return bg_task{task_id, process_info{watcher_pid, t}, info};
} break;
}
}
else
{
std::cerr << "Error on pipe(): " << strerror(errno) << "\n";
return bg_task{-1, process_info{-1, t}, process_info{}};
}
}
static void send_and_wait_cmd(struct netdev *nd, int cmd)
{
outw(cmd, Command);
wait_cmd(nd);
}
int main(int /* argc */, char* /* argv */[])
{
auto bg_tasks = std::map<int, bg_task>();
timeval start;
gettimeofday(&start, nullptr);
int next_task_id = 0;
bool quit = false;
while (not quit)
{
std::string line;
std::cout << get_current_dir_name() << "> ";
std::cout.flush();
if (not std::getline(std::cin, line) || line == "exit")
{
std::cout << std::endl;
quit = true;
}
else
{
auto is_whitespace = [](char c){
return std::isspace(c) != 0;
};
auto begin = std::find_if_not(line.begin(), line.end(), is_whitespace);
auto end = line.end();
auto result = begin;
std::vector<std::string> args;
while (begin != end)
{
result = std::find(begin, end, ' ');
args.emplace_back(begin, result);
begin = std::find_if_not(result, end, is_whitespace);
}
if (not args.empty())
{
if (args.back() == "&")
{
args.pop_back();
auto task = launch_background_cmd(next_task_id++, args);
std::cout << task << std::endl;
bg_tasks[task.exec_proc.id] = task;
}
else if (args[0] == "cd")
{
cd(args[1]);
}
else if (args[0] == "aptaches")
{
check_processes(bg_tasks);
// for (std::map<int, bg_task>::const_iterator it=bg_tasks.begin(); it!=bg_tasks.end(); ++it) {
for (auto pair : bg_tasks)
{
std::cout << pair.second << std::endl;
}
}
else
{
wait_cmd(launch_cmd(args));
}
}
}
}
/* Kill everything in bg_tasks */
check_processes(bg_tasks);
for (auto pair : bg_tasks)
{
kill(pair.second.exec_proc.id, SIGTERM);
}
}
