/* ========= BEGINNING OF MAIN ================= */
int main(int argc, char **argv){
int is_pipe_command; /* Bool: 1 if command contains pipes, 0 otherwise */
char *shell_prompt; /* The shell prompt */
char buf[1000]; /* For grabbing shell prompt from command line */
char **arg_array; /* Arguments to command to be executed */
IS mis; /* My input struct */
Command *com; /* Arbitrary command */
Pipe_Command *pip_com; /* Arbitrary pipe command */
/* Get shell prompt */
if (argc == 1) shell_prompt = strdup("PowerJ >> ");
else if (argc == 2){
sscanf(argv[1], "%s", buf);
if (strcmp(buf, "-") == 0) shell_prompt = NULL;
else shell_prompt = strdup(buf);
}
else{
printf("Usage: ./jsh prompt\n");
exit(1);
}
/* Initialize input struct and print shell prompt */
mis = new_inputstruct(NULL);
if (shell_prompt != NULL) printf("%s", shell_prompt);
/* Wait on user input */
while (get_line(mis) >= 0){
if (mis->NF > 0){ /* Use fields library to parse command */
is_pipe_command = check_for_pipes(mis);
if (is_pipe_command){
pip_com = create_pip_com(mis);
exec_pip_com(pip_com);
} else{
com = grab_com(mis);
execute_com(com);
}
}
if (shell_prompt != NULL) printf("%s", shell_prompt);
}
return 0;
}
/*
* The main shell function
*/
main() {
int i;
char **args;
int result;
int block;
int output;
int input;
int append;
int child_id;
int status;
char *output_filename;
char *input_filename;
// Set up the signal handler
sigset(SIGCHLD, sig_handler);
// memset(&sa, 0, sizeof(sa));
// sa.sa_handler = delete_zombies;
// if(sigaction(SIGCHLD, &sa, 0)) {
// perror("sigaction");
// return 1;
// }
// Loop forever
while(1) {
// Print out the prompt and get the input
printf("prompt->");
args = getaline();
// No input, continue
if(args[0] == NULL)
continue;
// Check for internal shell commands, such as exit
if(internal_command(args))
continue;
// Check for an ampersand
int block = should_block(args);
if(check_for_pipes(args)) {
int in = 0;
char **tmp_args = args;
char **ptr;
// loop over args, set each | to NULL
for(ptr = args; *ptr != NULL; ptr++) {
//printf("tmpargs[0]: %s [1]: %s [2]: %s\n", tmp_args[0], tmp_args[1], tmp_args[2]);
if(strcmp(*ptr, "|") == 0) {
free(*ptr);
*ptr = NULL;
// do stuff with tmp_args as your new "args"
int pipefd[2];
pipe(pipefd);
child_id = do_command(tmp_args, in, pipefd[1], 1, block);
close(pipefd[1]);
if(child_id < 0) {
printf("syntax error\n");
continue;
}
in = pipefd[0];
tmp_args = ptr + 1;
}
}
//printf("tmpargs[0]: %s [1]: %s\n", tmp_args[0], tmp_args[1]);
child_id = do_command(tmp_args, in, 1, 1, block);
if(child_id < 0) {
printf("syntax error\n");
continue;
}
} else {
child_id = do_command(args, 0, 0, 0, block);
if(child_id < 0) {
printf("syntax error\n");
continue;
}
}
// Wait for the child process to complete, if necessary
if(block) {
printf("Waiting for child, pid = %d\n", child_id);
result = waitpid(child_id, &status, 0);
}
}
}
