115 void shell_run_built_in_command(int index, int argc, char **argv)  in shell_run_built_in_command()  argument
117     if (index >= total_built_in_cmd_num)  in shell_run_built_in_command()
121     shell_cmds[index].func(argc, argv);  in shell_run_built_in_command()
154         int index = current_dir_len - 1;  in shell_cmd_cd()  local
155         for (; index > 1; --index)  in shell_cmd_cd()
157             if (shell_current_path[index] == '/')  in shell_cmd_cd()
160         shell_current_path[index] = '\0';  in shell_cmd_cd()
619     int index = 0; // 当前访问的是buf的第几位  in parse_command()  local
621     while (index < INPUT_BUFFER_SIZE && buf[index] == ' ')  in parse_command()
622         ++index;  in parse_command()
624     if (!buf[index])  in parse_command()
628     for (int i = index; i < (INPUT_BUFFER_SIZE - 1); ++i)  in parse_command()
643     for (int i = 0; i < *argc && index < INPUT_BUFFER_SIZE; ++i)  in parse_command()
646         *((*argv) + i) = &buf[index];  in parse_command()
647         while (index < (INPUT_BUFFER_SIZE - 1) && buf[index] && buf[index] != ' ')  in parse_command()
648             ++index;  in parse_command()
649         buf[index++] = '\0';  in parse_command()
652         while (index < INPUT_BUFFER_SIZE && buf[index] == ' ')  in parse_command()
653             ++index;  in parse_command()