Execl Linux - keep main program from closing

[john.halbert.37]

My problem I am having is when I use execl, it close my main program. I want the program I create can open other programs or create other actions with linux. I am looking to help getting on the right path. Should I be using execl? Why does it close the main program after it runs execl?

while (y0 != "no")
{
        cout << endl;
    cout << "How many I help you? Enter Command";
        cout << endl << "open" << endl << "close" << endl << "delete" << endl << "search" << endl << "Enter what program or file like to action ";
        cin >> y0 >> y1;


if (y0 == "open")
           {
cout << y1 << endl;
         if (y1 == "vlc")
         {
          strcpy(y3, "/usr/bin/");
          strcat (y3, y1);

          cout << "Enter path ";
          cin >> path;
          strcpy (y2, "/home/john/Videos/");
          strcat (y2, path);

          execl (y3,"vlc",y2);
          }


if (y1 != "vlc")
          {
           strcpy(y3, "/usr/bin/");
           strcat (y3, y1);
           execl (y3, "a");
           }

[ravenous]

execl is designed to exit your process and start a new one. I've never used it though. Try reading this, it looks like it has some useful information in it.

[john.halbert.37]

That link you gave me was for C, is it ok to mix c and c++? I know I am doing it now, does it really matter? Do I have any other choices another then execl to only Lunch a native Linux program that is already installed within my code? I am looking for books or websites to aid me if you have you would suggest.

[ravenous]

It's fine to use these functions from in your C++ programs. I'm not familiar with any other ways of doing this. I expect there are some though...

[john.halbert.37]

I need another tipper with the same code, change it up little to help resloved my problems. I need to use SQl now to help me pull the needed information. What I need help with is what is best for string to char.

using namespace std;
string programerfinder (string y1);
string pathfinder (string path);
int main()
{
string y1;
string path;
char y2[25];//path enter in search
char y3[330];//stores path for usr bin
y1 = programerfinder (y1);
path = pathfinder (path);


strcat (y3, y1);


execl ("/usr/bin/vlc","vlc");
}

string programerfinder (string y1)
{        
ifstream program;
program.open("program.txt");
getline (program,y1);
program.close();
return (y1);
}
string pathfinder (string path)
{
ifstream pathlist;
pathlist.open("test2.txt");
getline (pathlist,path);
pathlist.close();
return (path);
}

[ravenous]

I think you're hijacking your own thread here!

You should probably mark this one as solved and start a new thread with your new question :)

[Lucaci Andrew]

Here, maybe this function can help you: it mimics the function system from Windows:

int system (const char *command){
    int status;
    pid_t pid = fork ();
    if (pid == 0){
        execl ("/bin/sh", "/bin/sh", "-c", command, NULL);
        _exit (EXIT_FAILURE);
    }
    else if (pid < 0) status = -1;
    else 
        if (waitpid (pid, &status, 0) != pid) 
            status = -1;
    return status;
}

See how execl is used to start another process. Also, you could try combining threads with this function, starting a new thread for each call to this function.

[deceptikon]

it mimics the function system from Windows

system() is a standard C/C++ function, it's available on Linux too. ;) You probably knew that, of course, but your choice of phrase could be confusing to less experienced folks.

[Lucaci Andrew]

system() is a standard C/C++ function, it's available on Linux too. ;) You probably knew that, of course, but your choice of phrase could be confusing to less experienced folks.

Yes, indeed, my bad.
It was a quick example, for the execl function. :)

[john.halbert.37]

I added little more to the mixing pot but I thought I was using excel incorrectly at frist. The frist post made it sound like I should not do it that way. So I came up with this way. Please if you know a better way please help. I want to lanch a Linux program that I will not know but will be in usr/bin. I thought to laod the program with this command, then using shell script, keep the program alive that way. I create many small programs that open programs, find paths needed for the programs to open like movies, songs, and text docs etc. Make sure I am clear, I want to open up my resume, so my program will open a word program, find my resume on my computer for me, open the resume. As the user does not need to know where the resume is on the computer or network.