#include "smallsh.h" #include #include #include #include #include #include #include

#define MAX_JOBS 100

struct Job jobs[MAX_JOBS]; int numJobs = 0;

// Function declarations void handleSIGCHLD(int signo); void handleSIGINT(int signo); void handleSIGTSTP(int signo); void launchForeground(char* command, char* args[], int* status); void launchBackground(char* command, char* args[]); void updateJobsStatus(); void initJobs(); void addJob(pid_t pgid, const char* command, bool running); void removeJob(pid_t pgid); void printJobs();

int main() { // Set up signal handlers signal(SIGCHLD, handleSIGCHLD); signal(SIGINT, handleSIGINT); signal(SIGTSTP, handleSIGTSTP);

initJobs();

while (1) { char command[100]; // Get user input printf("Command> "); fgets(command, sizeof(command), stdin); command[strcspn(command, " ")] = '\0'; // Remove the newline character

// Exit the loop if the user enters "exit" or "quit" if (strcmp(command, "exit") == 0 || strcmp(command, "quit") == 0) { break; }

// Handle Ctrl+C if (strcmp(command, "^C") == 0) { if (jobs[0].running) { kill(-jobs[0].pgid, SIGINT); } else { printf("No foreground process to interrupt. "); } continue; // Skip to the next iteration }

// Handle Ctrl+Z if (strcmp(command, "^Z") == 0) { if (jobs[0].running) { kill(-jobs[0].pgid, SIGTSTP); addJob(jobs[0].pgid, jobs[0].command, false); } else { printf("No foreground process to suspend. "); } continue; // Skip to the next iteration }

}

return 0; }

// Implement other functions as needed

void handleSIGCHLD(int signo) { // Handle SIGCHLD to reap terminated child processes pid_t pid; int status;

while ((pid = waitpid(-1, &status, WNOHANG | WUNTRACED)) > 0) { // Find the job associated with the terminated process for (int i = 0; i

void handleSIGINT(int signo) { // Handle SIGINT (^C) if (jobs[0].running) { kill(-jobs[0].pgid, SIGINT); } else if (numJobs > 0) { // If there are background processes, interrupt the most recent one kill(-jobs[numJobs - 1].pgid, SIGINT); } else { printf("No process to interrupt. "); } }

void handleSIGTSTP(int signo) { // Handle SIGTSTP (^Z) if (jobs[0].running) { kill(-jobs[0].pgid, SIGTSTP); addJob(jobs[0].pgid, jobs[0].command, false); } else { printf("No foreground process to suspend. "); } }

void launchForeground(char* command, char* args[], int* status) { // Implement code to launch a process in the foreground pid_t pid = fork(); if (pid == 0) { setpgid(0, 0); execvp(command, args); perror("execvp"); exit(EXIT_FAILURE); } else if (pid

void launchBackground(char* command, char* args[]) { // Implement code to launch a process in the background pid_t pid = fork(); if (pid == 0) { setpgid(0, 0); execvp(command, args); perror("execvp"); exit(EXIT_FAILURE); } else if (pid

void updateJobsStatus() { for (int i = 0; i

if (result == -1) { perror("waitpid"); } else if (result > 0) { if (WIFEXITED(status) || WIFSIGNALED(status)) { // Process has exited or terminated jobs[i].running = false; printf("Job [%d] %s terminated ", i + 1, jobs[i].command); } else if (WIFSTOPPED(status)) { // Process has been stopped jobs[i].running = false; printf("Job [%d] %s stopped ", i + 1, jobs[i].command); } else if (WIFCONTINUED(status)) { // Process has been continued jobs[i].running = true; printf("Job [%d] %s continued ", i + 1, jobs[i].command); } } } }

void initJobs() { // Initialize the jobs array for (int i = 0; i

void addJob(pid_t pgid, const char* command, bool running) { // Add a new job to the jobs array if (numJobs

void removeJob(pid_t pgid) { // Remove a job from the jobs array for (int i = 0; i

void printJobs() { // Print the list of jobs printf("Jobs: "); for (int i = 0; i

run my code it doesnt get me the results i need because it always says No foreground process to suspend. did i do the right thing finish the entrie program forme with running code you will get a thumbs up

Vhat to submit Fu need to submit the following: (a) your "smallsh,s" and "smallsh,h" program files. (b) MS Word document including the screenshot from the following scenarios: (1) Scenario 1 S>./smallsh Command >./ progl\& Command >.progl\& Command >.progl C (2) Scenario 2 S>./smallsh Command > ./progl\& Command > ./progl\& Command > ./progl ' Z (3) Scenario 3 S>./smallsh Command >./ progl\& Command >./ progl\& Command > ./progl C Command > jobs (4) Scenario 4 S>./smallsh Command >./ progl\& Command >./ progl\& Command >.prog 1 ' Z Command > jobs (5) Scenario 5 S>./smallsh Command >./ progl\& Command >./ progl\& Command >.prog 1 'Z Example Suppose that you have a program that includes 1 fork system call. Let's name that executable file as "prog1". For example, you may use the following program as "prog1.c" int main() \{ int i=0; for (i=0;iprog1& Command > prog1\& Command > prog 1 ... Then there are 3 jobs created where each job contains 2 processes. One job is running in foreground, and two jobs are running in background. 1. Alter smallsh from Chapter 5 so that it handles interrupts more like a real shell: (1) Your smallsh process shouldn't be terminated upon CtrlC type-in. Currently, if you type CtrlC, your smallsh process will be terminated and exited. (2) When you type in in middle of executing your smallsh process, only your foreground process needs to be terminated. And, your smallsh process needs to print the next "Command > " prompt on a next line. (3) When you type in : Change a stopped or running background job to a running in the foreground. - kill : Terminate a job. Implement these commands in your smallsh routines for these purposes along with a simple data structure for maintaining the jobs and processes in each job. You may use process group concept in this implementation for maintaining processes in each job (job may be interpreted as a process group). If your program use fork() system calls, multiple children processes will be created which belong to the same job as your original process which spawned the children processes