/*
    slow
*/
func find_pid_by_cmdline(cmdline. char) int {
    import rt::c;
    alias   string = std::string,
            strings = std::strings;
    var dir void = opendir("/proc");
    defer closedir(dir);
    using ent. struct_dirent {
        while (ent = readdir(dir)) ~= null {
            if ent.d_type == DT_DIR {
                if  ent.d_name[0] == '.' and !ent.d_name[1] or
                    ent.d_name[1] == '.' and !ent.d_name[2] {
                    continue;
                }
                if isnumeric(&ent.d_name) {
                    lambda pread(cmd. char, lines. strings) bool [
                        var stream void = popen(cmd, "r");
                        if stream == null;
                            return false;
                        defer fclose(stream);
                        var line(0x200) char;
                        while fgets(&line, 0x200, stream) ~= null;
                            lines->add(&line);
                        return true;
                    ];
                    static cmd string;
                    static lines strings;
                    lines->clear();
                    if pread(cmd->format("sudo cat /proc/%s/cmdline", &ent.d_name), &lines) {
                        if !lines->empty() {
                            if !strcmp(lines->first_item(), cmdline);
                                return atoi(&ent.d_name);
                        }
                    }
                }
            }
        }
    }
    return -1;
}