//% help=control/in-background blockAllowMultiple=1
//% blockId="control_in_background" block="run in background" blockGap=8
void inBackground(Action a) {
runInBackground(a);
}
//This is the main loop that runs the shell and takes in the commands
int main(int argc, char const *argv[])
{
char *input;
pid_t childpid, pipeChild;
int status, execStatus, commandTwo;
int runInBG = 0, redirToFile = 0, pipefd[2];
struct sigaction childFinished;
childFinished.sa_sigaction = endSignal;
input = malloc(sizeof(char)*50);
printf("Welcome to MaSh, enter a command.\n");
printf(">");
fgets(input,50,stdin);
sigaction(SIGCHLD, &childFinished, NULL);
while(strcmp(input,"exit\n") != 0) {
runInBG = 0;
redirToFile = 0;
commandTwo = 0;
char **args = calloc(10,sizeof(char*));
//parse user input into argument array
status = parseInput(input,args);
if (status > 1)
runInBG = runInBackground(args,status);
if (status > 2)
redirToFile = redirectToFromFile(runInBG,args,status, &commandTwo);
childpid = fork();
if (childpid >= 0) { //fork success
if (childpid == 0) {
if (redirToFile == 1) {
execStatus = writeOptToFile(runInBG,args,status);
}
else if (redirToFile == 2) {
execStatus = readIptFromFile(runInBG,args,status);
}
else if (redirToFile == 3) {
//create pipe
if (pipe(pipefd) == -1) {
printf("Pipe failed.\n");
}
pipeChild = fork();
if (pipeChild >= 0) {
//read from the pipe
if (pipeChild == 0) {
close(1);
dup(pipefd[1]);
close(pipefd[0]);
execStatus = execvp(*args,args);
exit(0);
}
//write to the pipe
else {
close(0);
dup(pipefd[0]);
close(pipefd[1]);
execStatus = execvp(args[commandTwo],args+commandTwo);
}
}
else {
perror("Fork failed.");
exit(-1);
}
}
else {
//this is supposed to make the output of commands not appear on screen, it doesnt work though
if (runInBG == 1) {
setpgid(0,0);
}
execStatus = execvp(*args,args);
}
if (execStatus < 0) {
printf("Command \"%s\" not found.\n", input);
}
exit(0);
}
else {
//may not need to do this
if (runInBG == 1) {
waitpid(-1,&status,WNOHANG | WUNTRACED);
runInBG = 0;
}
else
waitpid(childpid,&status,0);
}
}
else {
printf("Fork failed.\n");
}
printf(">");
fgets(input,50,stdin);
free(args);
}
kill(childpid,SIGKILL);
printf("logout\n");
printf("\n");
printf("[Process completed]\n");
exit(0);
}
