How to launch to apps using fork() and execv: execv, fork

How to launch to apps using fork() and execv

Hi Experts,

I am trying to launch 2 apps. by using fork() and execv(); however, it launches only one. The code I wrote below:

pid_t pid;
int status;
const char* pPath_1="/home/test_1/test_1";
const char* pPath_2="/home/test_2/test_2";
char *app_1[] = {"test_1", NULL};
char *app_2[] = {"test_2", NULL};

pid = fork();

if(0 == pid)
{
printf("We are in child process\n");
printf("%d\n", pid);

if (execv (pPath_1, app_1) < 0)
{
printf("execv failed\n");
printf("Error code: %s\n", strerror(errno));
_exit(1);
}

if (execv (pPath_2, app_2) < 0)
{
printf("execv failed\n");
printf("Error code: %s\n", strerror(errno));
_exit(1);
}

}
else
{
printf("We are in parent\n");
printf("%d\n", pid);
wait(&status);
}

Please help me out with this problem. Thanks.
codelearner

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A successful call execv() replaces your current process with the new one, so the second call to execv() never gets called. You will need to call fork twice:

/* To run child 1 and child 2 sequentially */

c1pid = fork();
if(0 == c1pid)
{
printf("We are in first child process\n");
printf("%d\n", c1pid);

if (execv (pPath_1, app_1) < 0)
{
printf("execv failed\n");
printf("Error code: %s\n", strerror(errno));
       }
exit(1);
}

printf("We are in parent\n");
printf("%d\n", c1pid);
waitpid(c1pid, &status1, 0);

c2pid = fork();
if(0 == c2pid)
{
printf("We are in second child process\n");
printf("%d\n", c2pid);

if (execv (pPath_2, app_2) < 0)
{
printf("execv failed\n");
printf("Error code: %s\n", strerror(errno));
       }
exit(1);
}

printf("We are in parent\n");
printf("%d\n", c2pid);
waitpid(c2pid, &status2, 0);

/* To run child 1 and child 2 in parallel */

c1pid = fork();
if(0 == c1pid)
{
printf("We are in first child process\n");
printf("%d\n", c1pid);

if (execv (pPath_1, app_1) < 0)
{
printf("execv failed\n");
printf("Error code: %s\n", strerror(errno));
       }
exit(1);
}

printf("We are in parent\n");
printf("%d\n", c1pid);

c2pid = fork();
if(0 == c2pid)
{
printf("We are in second child process\n");
printf("%d\n", c2pid);

if (execv (pPath_2, app_2) < 0)
{
printf("execv failed\n");
printf("Error code: %s\n", strerror(errno));
       }
exit(1);
}

printf("We are in parent\n");
printf("%d\n", c2pid);
waitpid(c1pid, &status1, 0);
waitpid(c2pid, &status2, 0);

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How to launch to apps using fork() and execv

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