/* Prosty interpreter polece
 */
#include <sys/types.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <signal.h>
/*#include <wait.h>*/
#include <sys/wait.h>
#include <sys/resource.h>

#define INPUTSIZ        256
#define MAXPAR	5

void signal_handler(int sig) {
    pid_t pid;
    int status;
    signal(SIGCHLD,signal_handler);

    while( (pid=wait3(&status,0,0))>0 ){
		if(WIFEXITED(status)){
			printf("Proces nr %d zakonczony z kodem wyjscia %d\n",
				pid,WEXITSTATUS(status));
		}
		if(WIFSIGNALED(status)){
			printf("Proces nr %d dostal sygnal nr %d\n",
				pid,WTERMSIG(status));
		}
		if(WIFSTOPPED(status)){
			printf("Proces nr %d zatrzymany przez sygnal nr %d\n",
				pid, WSTOPSIG(status));
		}
	}
};

void *worker(void *arg) {
    sigset_t sig;
    sigemptyset(&sig);                                                                                                    
    sigaddset(&sig, SIGCHLD);                                                                                             
    pthread_sigmask(SIG_UNBLOCK,&sig,0);
    signal(SIGCHLD,signal_handler);
    while (1) 
	pause();
    return 0;
};

typedef struct {
    char znak;
    unsigned int jak_dlugo;
} dane_watkowe;


void *workerout(dane_watkowe *dw) {
    unsigned int counter;
    
    for (counter = 0; counter < (dw->jak_dlugo); counter++) {
	fprintf(stderr,"%c",dw->znak);
	sleep (1);
    }
    free (dw);
    return 0;
};

void doshell(char *cmd) {
	char *argv[MAXPAR+1], *p;
	int argc=0;
        pid_t pid;
	
/* Dzielenie linii polecen na "wyrazy" */
	if((argv[argc]=strtok(cmd," \t\n"))==NULL) return;
	while(argv[argc] && argc<MAXPAR-1){
		argv[++argc]=strtok(NULL," \t\n");
	}
	
	if (strcmp(argv[0],"koniec")==0) 
	    exit(0);
	else if (strcmp(argv[0],"output")==0)
	    if ((argc != 2) && (argc!=3)) {
	    	fprintf(stderr,"Bledne uzycie wbudowanej funkcji output:\nUzycie: output jak_dlugo [znak]\n");
		return;
	    } else {
		dane_watkowe *dw;
		dw = malloc(sizeof(dane_watkowe));
		if (argc == 3) 
		    dw->znak = *argv[2];
		else
		    dw->znak = '#';
		
		dw->jak_dlugo = atoi(argv[1]);
		pthread_create(0,0,workerout,dw);	
		return ;
	    }
	    
        if ( (pid = fork()) < 0) { 
		perror("Blad wywolania fork"); exit(2);
        }
        if (pid == 0) {
                execvp(argv[0],argv);
                perror("Blad wywolania execvp"); exit(1);
        }
	
}
int main() {
        char buf[INPUTSIZ];
	pthread_t tid;
	sigset_t sig;
	
	pthread_create(&tid,0,worker,0);
	sigemptyset(&sig);
        sigaddset(&sig, SIGCHLD);
	pthread_sigmask(SIG_BLOCK,&sig,0);

        printf("\n> ");
        while (fgets(buf, INPUTSIZ, stdin) != NULL) {
                doshell(buf);
                printf("\n> ");
        }
	
        exit(0);
}