For the following C++ Code: #include <stdio.h> #include <string> #include <iostr
ID: 3879042 • Letter: F
Question
For the following C++ Code:
#include <stdio.h>
#include <string>
#include <iostream>
#include <unistd.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <sstream>
#include <fstream>
#include <sys/stat.h>
#include <fcntl.h>
#include "Processes.h"
using namespace std;
pid_t process_id;
/*
* The starting point of the program.
*/
int main(void)
{
// Call the user-defined function that retrieves the process ID
cout << "Part 1: Working With Process IDs" << endl;
cout << "Process ID: " << getProcessID() << endl;
cout << endl << endl;
// Call the user-defined function that creates a new process
cout << "Part 2: Working With Multiple Processes" << endl;
cout << createNewProcess() << endl;
cout << endl << endl;
// Call the function that call an external OS command
if (process_id != 0)
{
cout << "Part 3: Working With External Commands" << endl;
char * args[3] = {(char * )"ls", (char * )"-l", NULL};
replaceProcess(args);
cout << endl;
}
return 0;
}
Use the following C++ code to complete:
#ifndef Processes_cpp
#define Processes_cpp
#include "Processes.h"
using namespace std;
// Part 1: Working With Process IDs
pid_t getProcessID(void)
{
// TODO: Add your code here
return -1;
}
// Part 2: Working With Multiple Processes
string createNewProcess(void)
{
pid_t id = fork();
// DO NOT CHANGE THIS LINE OF CODE
process_id = id;
if(id == -1)
{
return "Error creating process";
}
else if (id == 0)
{
// TODO: Add your code here
return "";
}
else
{
// TODO: Add your code here
return "";
}
}
// Part 3: Working With External Commands"
void replaceProcess(char * args[])
{
// Spawn a process to execute the user's command.
pid_t id = fork();
// TODO: Add your code here
}
#endif /* TestProg_cpp */
Correct code output:
1. Modify the getProcessID() function in the file named Processes.cpp a. The function must find and store the process's own process id b. The function must return the process id to the calling program. Hint: search for "process id" in the "System Calls" section of the Linux manual.Explanation / Answer
//main.cpp
#include <stdio.h>
#include <string>
#include <iostream>
#include <unistd.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <sstream>
#include <fstream>
#include <sys/stat.h>
#include <fcntl.h>
#include "Processes.h"
using namespace std;
pid_t process_id;
int main(void)
{ cout << "Part 1: Working With Process IDs" << endl;
cout << "Process ID: " << getProcessID() << endl;
cout << endl << endl;
cout << "Part 2: Working With Multiple Processes" << endl;
cout << createNewProcess() << endl;
cout << endl << endl;
if (process_id != 0)
{
cout << "Part 3: Working With External Commands" << endl;
char * args[3] = {(char * )"ls", (char * )"-l", NULL};
replaceProcess(args);
cout << endl;
}
return 0;
}
===========================================================================
///Processes.cpp
#ifndef Processes_cpp
#define Processes_cpp
#include "Processes.h"
using namespace std;
pid_t getProcessID(void)
{
pid_t id= getpid();
return id;
}
string createNewProcess(void)
{
pid_t id = fork();
process_id = id;
if(id == -1)
{
return "Error creating process";
}
else if (id == 0)
{
cout << "I am a child process! ";
return "I am bored of my parent, switching programs now";
}
else
{
cout << "I just became a parent! ";
int status=0;
wait(&status);
return "My child process just terminated!";
}
}
void replaceProcess(char * args[])
{
pid_t id = fork();
execvp(args[0], args);
}
#endif /* TestProg_cpp */
===========================================================================
//
// Processes.H
#ifndef Processes_h
#define Processes_h
#include <stdio.h>
#include <string>
#include <iostream>
#include <unistd.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <sstream>
#include <fstream>
#include <sys/stat.h>
#include <fcntl.h>
using namespace std;
extern pid_t process_id;
pid_t getProcessID(void);
string createNewProcess(void);
void replaceProcess(char * args[]);
#endif /* Processes_h */
===============================================================================