/*
* builtin_cmd - If the user has typed a built-in command then execute
* it immediately.
*/
int builtin_cmd(char **argv)
{
char *cmd = argv[0];
if (!strcmp(cmd, "help")) { /* quit command */
do_help();
return 1;
}
if (!strcmp(cmd, "stop")) { /* quit command */
do_stop(argv);
return 1;
}
if (!strcmp(cmd, "exit")) { /* quit command */
do_exit();
return 1;
}
if (!strcmp(cmd, "jobs")) { /* jobs command */
do_jobs();
return 1;
}
if (!strcmp(cmd, "bg")) { /* bg and fg commands */
do_bg(argv);
return 1;
}
if (!strcmp(cmd, "fg")) { /* bg and fg commands */
do_fg(argv);
return 1;
}
if (!strcmp(cmd, "kill")) { /* bg and fg commands */
do_kill(argv);
return 1;
}
return 0; /* not a builtin command */
}
int main(int argc, char** argv) {
ssize_t cmd_size;
int i;
int pipefd[2], fin, fout;
char buf[BUFFER_SIZE];
char *cmd;
char **args;
job *j;
job_list = init_list();
msg_q = init_list();
pid_t pgid;
/* initial setup */
shell_pgid = getpgid(0);
sync_pwd();
/* disable (ignore) job control signals */
signal(SIGTTOU, SIG_IGN);
signal(SIGTTIN, SIG_IGN);
signal(SIGTERM, SIG_IGN);
signal(SIGTSTP, SIG_IGN);
signal(SIGINT, SIG_IGN);
set_handler();
/*** Shell loop ***/
for(;;) {
/* Print out queued messages */
for(i=0;i<msg_q->size;i++) {
message *m = (message *) get(msg_q, i);
printf("%s: %s\n", m->status ? "Finished" : "Stopped", m->msg);
}
// clear the queue
while(msg_q->size > 0)
free(del(msg_q,0));
/* TODO: shell print macro */
printf("%s %s %s ", SHELL, pwd, PROMPT);
fflush(stdout);
do
cmd_size = read(STDIN_FILENO, buf, BUFFER_SIZE);
while(cmd_size == -1 && errno == EINTR); // ignore system call interrupts
if(cmd_size == -1) {
perror("read");
continue;
} else if(cmd_size == 0) { // EOF (quit)
write(STDOUT_FILENO, EXIT_MSG, STRING_SIZE(EXIT_MSG));
cleanup();
_exit(EXIT_SUCCESS);
} else if(cmd_size == 1 && buf[0] == '\n') {
continue;
}
if(buf[cmd_size-1] != '\n') { // overflow
write(STDOUT_FILENO, OFLOW_MSG, STRING_SIZE(OFLOW_MSG));
pflush();
continue;
}
buf[cmd_size-1] = '\0'; // strip the newline
j = parse(buf);
if(j == (job *) NULL) {
printf("Invalid redirections you moron!\n");
continue;
}
args = j->cmds[0];
if (!my_strcmp(args[0], "fg")) {
do_fg(args);
free_job(j);
continue;
} else if (!my_strcmp(args[0], "bg")) {
do_bg(args);
free_job(j);
continue;
} else if (!my_strcmp(args[0], "jobs")) {
print_bg(job_list);
free_job(j);
continue;
} else if (!my_strcmp(args[0], "cd")) {
do_cd(args);
free_job(j);
continue;
}
j->job_id = gen_job_id(job_list);
j->running = 1;
j->complete = 0;
push(job_list, JOB, (void *)j);
pgid = 0; // set the job pgid to be the first child's pid
fin = STDIN_FILENO;
for(i=0;i<(j->numcmds);i++) {
args = j->cmds[i];
cmd = args[0];
if(i + 1 < (j->numcmds)) { // not last process in job
//printf("Creating a pipe!\n");
if(pipe(pipefd) == -1) {
perror("pipe");
exit(EXIT_FAILURE);
}
fout = pipefd[1];
}
else
fout = STDOUT_FILENO;
/*printf("Forking %s\n", cmd);
k = 0;
while( args[k] != (char *) NULL ) {
printf("\targv[%d] = %s\n", k, args[k]);
++k;
}*/
pid = fork();
if(pid == -1) {
perror("fork");
continue;
}
/*** CHILD ***/
if(!pid) {
// <
if(j->fin[i] != (char *) NULL) {
if( (fin = open(j->fin[i], O_RDONLY)) == -1 ) {
perror("open");
}
}
// >
if(j->fout[i] != (char *) NULL) {
if( (fout = open(j->fout[i], O_WRONLY | O_CREAT | O_TRUNC, 0644)) == -1 ) {
perror("open");
}
}
exec_process(cmd, args, pgid, fin, fout, j->fg);
}
/*** PARENT ***/
else {
if(!pgid) { // set to first child's pid (process group leader)
pgid = pid;
j->pgid = pgid;
//printf("Set job's pgid to %d\n", pgid);
}
process *proc = malloc(sizeof(process));
proc->complete = 0;
proc->pid = pid;
proc->pgid = pgid;
push(j->pid_list, PROCESS, (void *)proc);
if( setpgid(pid, pgid) == -1 ) {
perror("setpgid");
_exit(EXIT_FAILURE);
}
}
if(fin != STDIN_FILENO)
close(fin);
if(fout != STDOUT_FILENO)
close(fout);
fin = pipefd[0];
}
//print_jobs();
if(j->fg) { // foreground
// give terminal control to job
if( tcsetpgrp(STDIN_FILENO, pgid) == -1 ) {
perror("tcsetpgrp");
_exit(EXIT_FAILURE);
}
// wait for job to finish
jwait(j);
// give pmsh terminal control again
if( tcsetpgrp(STDIN_FILENO, shell_pgid) == -1 ) {
perror("tcsetpgrp");
_exit(EXIT_FAILURE);
}
}
else { // background
printf("Running: %s\n", j->rawcmd);
}
}
}
