execAndRedirect.cpp

bool execAndRedirect(std::string command, std::vector<std::string> args, std::string& output, int& status)
{
    int error;
    int pipefd[2];
    int localStatus;

    if (pipe(pipefd) == -1)
    {
        error = errno;
        cerr << "Executing command '" << command << "' failed: " << strerror(error) << endl;
        return false;
    }

    pid_t pid = fork();

    if (pid == 0)
    {
        char** argsC;

        argsC = new char*[args.size() + 2];

        argsC[0] = new char[command.size() + 1];

        strncpy(argsC[0], command.c_str(), command.size());

        argsC[0][command.size()] = '\0';

        for (size_t count = 0; count < args.size(); count++)
        {
            argsC[count + 1] = new char[args[count].size() + 1];

            strncpy(argsC[count + 1], args[count].c_str(), args[count].size());

            argsC[count + 1][args[count].size()] = '\0';
        }

        argsC[args.size() + 1] = NULL;

        close(pipefd[0]);

        if (dup2(pipefd[1], STDOUT_FILENO) == -1)
        {
            error = errno;
            cerr << "Executing command '" << command << "' failed: " << strerror(error) << endl;
            exit(1);
        }

        if (dup2(pipefd[1], STDERR_FILENO) == -1)
        {
            error = errno;
            cerr << "Executing command '" << command << "' failed: " << strerror(error) << endl;
            exit(1);
        }

        close(pipefd[1]);

        if (execvp(command.c_str(), argsC) == -1)
        {
            error = errno;
            cerr << "Executing command '" << command << "' failed: " << strerror(error) << endl;
            exit(1);
        }
    }

    else if (pid > 0)
    {
        size_t BUFFER_SIZE = 1024;
        char buffer[BUFFER_SIZE + 1];

        close(pipefd[1]);

        ostringstream oss;

        ssize_t num_b;

        while ((num_b = read(pipefd[0], buffer, BUFFER_SIZE)) != 0)
        {
            buffer[num_b] = '\0';

            oss << buffer;
        }

        output = oss.str();

        waitpid(pid, &localStatus, 0);

        close(pipefd[0]);
    }

    else
    {
        error = errno;
        cerr << "Executing command '" << command << "' failed: " << strerror(error) << endl;
        return false;
    }

    if(WIFEXITED(localStatus))
    {
        status = WEXITSTATUS(localStatus);

        DateTime current = DateTime::now();

        if(status == 0)
        {
            return true;
        }

        else
        {
            return false;
        }
    }

    else
    {
        error = errno;
        cerr << "Executing command '" << command << "' failed: child didn't terminate normally" << endl;
        return false;
    }
}