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Command Line Tools

3. Shell UI

2019-03-27Original-language archivelegacy assets may be incomplete

Escape Code

Escape Sequence Representation
\a alert
\n newline
\t Horizontal Tab
\v Vertical Tab
',",? Symbol
\nnn ASCII in octal
\xhh ASCII
\uhhhh Unicode
\uhhhhhhhh Unicode

Escape Character

echo -e "\033[32;31mstring \033[0m" # Different format seperated by ;
echo "\e[32;31mstring\e[0m"
echo "\x1b[32;31mstring\x1b[0m"

(x): not work in iterm

Format Representation
0 Default
1 Dim
4 Underline
5 Blink (x)
7 Reverse (invert the foreground and background colors)
8 Hidden (x)
9 strikes (x)
20+i Reset above values
39 Default fg color
30+i 8 color: Black,R,G,Y,B,M,C,Light gray
90+i 16 color: Dark gray,lR,lG,lY,lB,lM,lC,W
38;5;ASCII 256 color
38;2;R;G;B RGB color
49 Default bg color
40+i 8 color for bg
100+i 16 color for bg
48;5;ASCII 256 color
48;2;R;G;B RGB color

Without m:

Name Representation
K Delete everything from the cursor to the end of the line.
2K erases everything written on line before this
nA moves cursor n line above
nB moves cursor n line under
nC moves cursor n spacing to the right
nD moves cursor n spacing to the left
s save cursor position
u restore cursor position
?25l Hide cursor
?25h Show cursor
H Move the cursor to the upper-left corner of the screen
r;cH Move the cursor to row r, column c (Start at 1)
2J Clear the screen

terminfo

使用 tput 调用 terminfo 数据库

echo $(tput setab 0)$(tput setaf 1)'string' # Set background and foreground
echo $(tput bold)'string' # dim, smul, rmul, rev, smso, rmso, sgr0
echo $(tput clear) # 清屏
echo $(tput sc) # 保存当前光标位置
echo $(tput cup 10 13) # 光标移动
echo $(tput civis) # 光标不可见
echo $(tput cnorm) # 光标可见
echo $(tput rc) # 显示输出

C Program

  • isattr(STDOUT_FILENO): 判断是否为终端
  • 屏幕输入：<termios.h> <unistd.h>
    • tcgetattr
    • tcsetattr
  • 获取终端大小：<sys/ioctl.h>
    • struct winsize w
    • ioctl(STDOUT_FILENO, TIOCGWINSZ, &w);
    • w.ws_row, w.ws_col

tcgetattr

int tcgetattr(int fd, struct termios *termios_p);

  • struct termios
    • c_iflag 输入模式
    • c_oflag 输出模式
    • c_cflag 控制模式
    • c_lflag 局部模式
      • ECHO 显示字符
      • ICANON 启用特殊字符
    • c_cc 特殊控制字符

tcsetattr

int tcsetattr(int fd, int optional_actions, const struct termios *termios_p);

  • STDIN_FILENO: 标准输入
  • optional_action:
    • TCSANOW 立即改变
    • TCSADRAIN 当目前输出完成时改变
    • TCSAFLUSH 当目前输入完成时改变并舍弃目前所有输入
void setBufferedInput(bool enable) {
  static bool enabled = true;
  static struct termios old;
  struct termios new;
 
  if (enable && !enabled) {
    tcsetattr(STDIN_FILENO,TCSANOW,&old);
    enabled = true;
  } else if (!enable && enabled) {
    tcgetattr(STDIN_FILENO,&new);
    old = new;
    new.c_lflag &=(~ICANON & ~ECHO);
    tcsetattr(STDIN_FILENO,TCSANOW,&new);
    enabled = false;
  }
}

游戏模型

next_frame = 0;
while (1) {
  while (uptime() < next_frame) ; // 等待一帧的到来
  while ((key = readkey()) != _KEY_NONE) {
    kbd_event(key);         // 处理键盘事件
  }
  game_progress();          // 处理一帧游戏逻辑，更新物体的位置等
  screen_update();          // 重新绘制屏幕
  next_frame += 1000 / FPS; // 计算下一帧的时间
}