Linux_Lab_3

Linux_Lab_3

//  Linux_Lab_3
//
//  Created by Sergiy on 25.01.17.

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <string.h>



int main(int argc, const char * argv[])
{
    const char *textFile;
    pid_t pid = fork();
    int ret;
    
    const char *emailBegin;
    const char *emailAddress;
    const char *emailEnd;
    char *emailCommand;
    
    size_t length;
    
    if (argc > 1)
    {
        textFile = argv[1];
    }
    else
    {
        textFile = "/Users/Sergiy/Desktop/congrats.c";
    }
    
    if (pid == 0)
    {
        printf("This is a child process\n");
        
        printf("Calling execl....\n");
        
        ret = execl("/usr/bin/head", "head", textFile, NULL);
        
        printf("Failed execl... ret = %d\n", ret);
    }
    else
    {
        sleep(3);
        
        printf("\nThis is parent process\n\n");
        
        popen("/usr/bin/who", "w");
        
        sleep(1);
        
        printf("\n--------\n\n");
        
        popen("/usr/bin/mail", "w");
        
        sleep(1);
        
        printf("\n--------\n\n");
        
        emailBegin = "/usr/bin/mail -s \"Congratulations\" ";
        emailEnd = " < /Users/Sergiy/Desktop/congrats.c";
        
        for (int i = 2; i < argc; i++)
        {
            emailAddress = argv[i];
            
            length = strlen(emailBegin) + strlen(emailAddress) + strlen(emailEnd);
            
            emailCommand = malloc(length);
            
            strcat(emailCommand, emailBegin);
            strcat(emailCommand, emailAddress);
            strcat(emailCommand, emailEnd);
            
            popen(emailCommand, "w");
        }
        
        waitpid(pid, 0, 0);
    }
    
    return 0;
}