Function read_output

src/debug.cpp:93–127

* Execute the given command and read the first line of its output. * * Returns an empty string in case of an error. */

 * Returns an empty string in case of an error.
 */
std::string read_output(std::string command)
{
    // Open a pipe stream to read the output of the process `command`.
    FILE *file = popen(command.c_str(), "r");
    if (!file)
    {
        // popen failed.
        return {};
    }

    // Read the first line, up till and including the first newline if any, into a buffer.
    char buffer[MAX_FUNCTION_NAME + 1]; // +1 for the terminating zero.
    char *line_as_c_str = fgets(buffer, sizeof(buffer), file);

    // We're done with the pipe stream now.
    pclose(file);

    if (!line_as_c_str)
    {
        // fgets returned an error.
        return {};
    }

    // If fgets returns non-NULL then the string is guaranteed to be zero terminated.
    size_t len = std::strlen(line_as_c_str);

    // Strip the trailing newline, if any.
    if ((len > 0) && (line_as_c_str[len - 1] == '\n'))
    {
        --len;
        line_as_c_str[len] = 0;
    }

    return {buffer, len};
}

/**
 * Try to find the correct path to the given executable.