popen() alternative

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Why aren’t you using pipe/fork/exec method?

pid_t pid = 0;
int pipefd[2];
FILE* output;
char line[256];
int status;

pipe(pipefd); //create a pipe
pid = fork(); //span a child process
if (pid == 0)
{
// Child. Let's redirect its standard output to our pipe and replace process with tail
 close(pipefd[0]);
 dup2(pipefd[1], STDOUT_FILENO);
 dup2(pipefd[1], STDERR_FILENO);
 execl("/usr/bin/tail", "/usr/bin/tail", "-f", "path/to/your/file", (char*) NULL);
}

//Only parent gets here. Listen to what the tail says
close(pipefd[1]);
output = fdopen(pipefd[0], "r");

while(fgets(line, sizeof(line), output)) //listen to what tail writes to its standard output
{
//if you need to kill the tail application, just kill it:
  if(something_goes_wrong)
    kill(pid, SIGKILL);
}

//or wait for the child process to terminate
waitpid(pid, &status, 0);

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