void jobs() {
#ifdef DEBUG
/* printf("jobs()\n"); */
#endif
check_background_processes();
traverse_job_list(&printer);
}
int
jobs_command(void) {
struct joblist * job;
check_background_processes();
job = jobs;
while(job) {
printf("[%d] %d %s\n", job->jobid, job->pid, job->command);
job = job->next;
}
return 0;
}
//MAIN
int main(int argc, char **argv) {
//mtrace();//to check memory leakage problems
//Initialize prev_rusage with 0 values
struct rusage usage;
int status = 0;//return from wait function
int background = FALSE;//flag that indicate if a command is supposed to run on background or not
char str[129];//input string
char* cmd_args[32]; //vector of strings (arguments for the shell)
struct timeval init, end; //checkpoint to measure wall-clock time
bgprocessLL bgpLL = init_bgprocessLL();//store the background processes (LL: linked list)
while(1) {
printf(">");//prompt character
//Get input
if(fgets(str,129,stdin)==NULL){//EOF or error (to be able to pipe input files)
wait4bgprocess(&bgpLL);
break;
}
//parse commands in str to cmd_args (array of string) to be used in exec functions
int n_args = args_from_str(str, cmd_args);
//check if cmd_args has built-in commands
int builtin_effect = treat_builtin_cmds(cmd_args, n_args, &bgpLL);
if(builtin_effect==CONTINUE) continue;
else if (builtin_effect==BREAK) break;
//else: continue normally
//Check if the process is supposed to run in background
if(strcmp(cmd_args[n_args-1],"&") == 0) {
free(cmd_args[n_args-1]);//transparent to the rest
cmd_args[n_args-1]=NULL;//necesary condition for exec functions
n_args--;
background = TRUE;
}else
background = FALSE;
gettimeofday(&init,NULL);//get time right before creating the child
pid_t pid = fork(); //create a new process
//CHILD
if (pid == 0) {
if(execvp(cmd_args[0], cmd_args) == -1){ //error with de command
perror(NULL);//print error message
//free_args(cmd_args);//free memory allocaded in args_from_cmdline function
exit(EXIT_FAILURE);
}
}else if (pid > 0) { //PARENT
if(background == FALSE) {//false
while(1) {
int pid_done = wait3(&status, 0, &usage);//wait for any children
gettimeofday(&end, NULL);//get end time
if(pid_done!=pid) {//it's not the calling non-background child (a background process has finished)
bgprocess bgp = remove_bgprocess(&bgpLL, pid_done);//get the information about it
print_bgprocess(bgp, "completed");//show which one has finished
print_report(diff_time(bgp.init_time,end), usage, status);//print running status
free_bgprocess_name(&bgp);//to avoid memory leak
}else {//it's not the calling non-background child (pid_done==pid)
print_report(diff_time(init,end), usage, status);//print running status
break;
}
}
}else {//It is a background process
bgprocess bgp = init_bgprocess(pid, init, cmd_args[0],0,NULL);//bgp null initialization
add2bgprocessLL(&bgpLL, bgp);//add the information to the linked list
free_bgprocess_name(&bgp);//avoid memory leaks
print_bgprocess(*bgpLL.first, "");//print the information about the background process
}
free_args(cmd_args);//free memory allocaded in args_from_str function
}else { //error
perror(NULL);//error in fork
free_args(cmd_args);//free memory allocaded in args_from_str function
exit(EXIT_FAILURE);
}
//Check for completed background processes and print their status
check_background_processes(&bgpLL, WNOHANG);
}
//free_args(cmd_args);//free memory allocaded in args_from_str function
return 0;
}
