#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <pthread.h>
#include <error.h>
#include <errno.h>
#include <signal.h>



void signal_handler(int signo) {
if(signo == SIGINT) {
    write(STDOUT_FILENO, "Interrupt signal received.", 27);
    exit(0);
}

if(signo == SIGTERM) {
    write(STDOUT_FILENO, "Terminate signal received.", 26);
    exit(0);
}

}
int sock;

int main() {
signal(SIGINT, signal_handler);
signal(SIGTERM, signal_handler);

struct sockaddr_in server;
struct hostent *hp;
char buf[1024];

//Thread func


/* Create socket */
sock = socket(AF_INET, SOCK_STREAM, 0);
if (sock < 0) {
    perror("opening stream socket");
    exit(1);
}
while(1) {
    write(STDOUT_FILENO, "Client Running!nEnter the IP address to    connect to: ", 52);
    char ip[20];
    int rip = read(STDIN_FILENO, ip, 20);
    ip[rip - 1] = '';

    write(STDOUT_FILENO, "nEnter the port to connect to: ", 31);
    char port[10];
    int rpo = read(STDIN_FILENO, ip, 10);
    port[rpo - 1] = '';
    //printf("%s %s", ip, port);

    /* Connect socket using name specified by command line. */
    server.sin_family = AF_INET;
    hp = gethostbyname(ip);
    if (hp == 0) {
    perror("");
    fprintf(stderr, "%s: unknown hostn", ip);
    exit(2);
    }
    bcopy(hp->h_addr, &server.sin_addr, hp->h_length);
    server.sin_port = htons(atoi(port));

    if (connect(sock,(struct sockaddr *) &server,sizeof(server)) < 0)      {
    perror("connecting stream socket");
    exit(1);
    }

    while(1) {
        char buff[50];
        int rc = read(STDIN_FILENO, buff, 50);

        if(rc == 0) {
                    write(STDOUT_FILENO, "Invalid Command.n", 16);
            }

        buff[rc - 1] = '';
        if((strcasecmp(buff, "exit") == 0)) {
                write(sock, "Client Disconnected.n", 22);
                close(sock);
                exit(0);
        }
        else {
            if (write(sock, buff, (rc - 1))< 0) {
                perror("writing on stream socket");
            }

        }
    }

    close(sock);
    }
   }

#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <errno.h>
#include <netdb.h>
#include <stdio.h>
#include <sys/wait.h>
#include <wait.h>
#include <string.h>
#include <unistd.h>
#include <signal.h>
#include <stdlib.h>
#include <stdio.h>

struct Process {
char name[50];
int pid;
char status[50];
time_t stime;
time_t etime;

};
struct Process *pro;
int pc = 0;
int msgsock;
char *array;

void signal_handler(int signo) {
if(signo == SIGINT) {
    write(STDOUT_FILENO, "Interrupt signal received.", 27);
    exit(0);
}

if(signo == SIGTERM) {
    write(STDOUT_FILENO, "Terminate signal received.", 26);
    exit(0);
}

}

void add() {

int sum=0;
    while (array!=NULL) {
        int a = atoi(array);
        sum= sum+a;
        array= strtok(NULL, " n");
}
char b[50];
int count=sprintf(b, "Sum: %dn", sum);
write(msgsock, b, count);

}

void subt() {

int subt=atoi(array);
array = strtok(NULL, " n");

    while (array!=NULL) {
        int a = atoi(array);
        subt= subt-a;
        array= strtok(NULL, " n");
    }

char b[50];
int count=sprintf(b, "Subtract Result: %dn", subt);
write(msgsock, b, count);
}

void mult() {

int sum=1;
while (array!=NULL) {
    int a = atoi(array);
    sum= sum*a;
    array= strtok(NULL, " n");
}
char b[50];
int count=sprintf(b, "Product: %dn", sum);
write(msgsock, b, count);
}

void run() {
int status;
char path[50];
    strcpy(path,"/usr/bin/");

int cpid = fork();

if(cpid > 0) {
    //Parent
    pid_t wid = waitpid(cpid, &status, WNOHANG);
    if (wid == 0) {
        write(STDOUT_FILENO, "Exec successfuln", 16);
        pro[pc].pid = cpid;

        strcpy(pro[pc].name, array);
        strcpy(pro[pc].status, "active");

        struct timeval tv1;
        gettimeofday(&tv1, NULL);
        pro[pc].stime = tv1.tv_sec;
        pro[pc].etime = NULL;

    }
    else {
        write(STDOUT_FILENO, "Exec Unsuccessfuln", 18);
    }
}

if(cpid == 0) {
    //Child
    strcat(path, array);
    int new = execl(path,"",NULL);
        if(new == -1) {
                write(msgsock, "No such file.n", 14);
                perror("exec failed");
                exit(EXIT_FAILURE);
        }

}

}

void list() {

write(msgsock, "PNAME       PID        STATUS           START_TIME           END_TIMEn", sizeof("PNAME     PID        STATUS           START_TIME           END_TIMEn"));


for(int j = 0; j < pc; j++) {

            char temp[500];
            char list= sprintf(temp, "n%s      %d      %s      %ld     %ldn", pro[j].name, pro[j].pid, pro[j].status,         pro[j].stime, pro[j].etime);

                write(msgsock, temp, list);

}

}

void terminate() {
if(array != NULL) {
    int count = 0;
    int freshKill = 0;
    for(int j = 0; j < pc; j++) {
        if((strcasecmp(pro[j].name, array) == 0) &&        (strcasecmp(pro[j].status, "active") == 0)) {
            freshKill = kill(pro[j].pid, SIGTERM);
                    if(freshKill == 0) {
                strcpy(pro[j].status, "inactive");
                struct timeval tv2;
                gettimeofday(&tv2, NULL);
                pro[j].etime = tv2.tv_sec;
                            write(msgsock, "Program terminated.n", 20);
                    }
                    else if (freshKill == -1) {
                            perror("kill");
                    }
                count++;
        }
        }



    if(count == 0) {
        write(msgsock, "Unable to terminate. Program name or id mismatch.n", 50);
    }
}
}





int main() {

int sock, length;

struct sockaddr_in server, clientinfo;
char buf[1024];
//char buf2[1024];
int rval;
int rval2;
int i;


sock = socket(AF_INET, SOCK_STREAM, 0);
if (sock < 0) {
    perror("opening stream socket");
    exit(1);
}
/* Name socket using wildcards */
server.sin_family = AF_INET;
server.sin_addr.s_addr = INADDR_ANY;
server.sin_port = 0;
if (bind(sock, (struct sockaddr *) &server, sizeof(server))) {
    perror("binding stream socket");
    exit(1);
}
/* Find out assigned port number and print it out */
length = sizeof(server);
if (getsockname(sock, (struct sockaddr *) &server, &length)) {
    perror("getting socket name");
    exit(1);
}
printf("Socket has port #%dn", ntohs(server.sin_port));
fflush(stdout);

/* Start accepting connections */
listen(sock, 5);

do {
    //char buffer[1024];
    msgsock = accept(sock, 0, 0);
    if(msgsock == -1) {
        perror("accept");
    }
    else do {
        bzero(buf, sizeof(buf));
        if ((rval = read(msgsock, buf, 1024)) < 0)
            perror("reading stream message");

        if (rval == 0)
            printf("Ending connectionn");


        array = strtok(buf, " n");

        if(array == NULL)
            continue;

        if(strcasecmp(array, "run")==0) {
                           //write(msgsock, "Message received at server."n, 27);
                            array =strtok(NULL," n");
                            run();
                    }

        else if(strcasecmp(array, "add")==0) {
            array = strtok(NULL, " n");
            add();
        }

        else if(strcasecmp(array, "subt")==0) {
            array = strtok(NULL, " n");
            subt();
        }

        else if (strcasecmp(array, "mult")==0) {
                            array =strtok(NULL, " ");
                            mult();
                    }

        else if(strcasecmp(array, "list")==0) {
            array = strtok(NULL, " n");
            list();
        }

        else if(strcasecmp(array, "terminate")==0) {
            array = strtok(NULL, " n");
            terminate();
        }

        else {
            write(msgsock, "Invalid commandn", 16);
        }


    } while(rval != 0);
    close(msgsock);

} while(1);

}