残培和的putChar不工作没有回报 [英] getch and putchar not working without return

问题描述

我一直在试图让残培来在没有成功的另一个程序中工作。所以，我做了我可以使用残培我希望它在主程序中的工作方式最基本的程序。

我已经研究了 NOECHO ， CBREAK ， initscr的和 NODELAY ，我也尝试过使用 newscr（）但都没有成功。

我遇到的问题是，字符不会被显示在屏幕上，直到我打进的时候，他们应该是把来每次循环屏幕。这究竟是为什么？也光标没有在新线路返回到屏幕的左侧。例如：

  ABC
   DEF
      GHI
 

我看过的答案，但我再次难倒...

 的#include＆LT;＆stdio.h中GT;
＃包括LT＆;＆ncurses.h GT;诠释的main（）
  {
     initscr的（）; CBREAK（）; NOECHO（）; NODELAY（stdscr上，0）;
    焦炭℃;
    而（（C =残培（））！= EOF）{
    的putchar（三）;}    返回0;
  }
 




解决方案

您没有看到输出，因为你的标准输出流线缓冲。

您的程序越来越单个字符的所有权利;但输出流被缓冲。

尝试 fflush（标准输出）; 或切换标准输出来缓冲模式与则setbuf（标准输出，NULL）;

与禁用缓冲的问题是，它是低效率的批量数据处理时的输出不是终端

您可以使它有条件的标准输出是一个TTY：

 如果（isatty（的fileno（标准输出）））/ *＃包括LT＆;＆unistd.h中GT; * /
  则setbuf（标准输出，NULL）;
 

要返回光标到行的开始，你需要拿出一个回车 \\ r 。这是因为诅咒 CBREAK 模式已停用 ONLCR TTY模式（输出，发送时NL添加CR）。

如果您无条件地添加 \\ r ，那么当你的输出重定向它将出现在文件中。所以，再一次你需要一些 isatty 破解。

有一个更好的可能是学习如何使用 tcgetattr 和 tcsetattr 函数precisely控制具体参数TTY，如果你想要的是做字符在-A-时间输入没有回声，而不是实际开发交互式基于光标的计划。

你真的想要的字符在-A-时间输入，或者只是魔鬼的回声？这很容易禁止回声。呼叫 tcgetattr 来填补结构的termios 与文件描述符0的当前设置（如果它是一个TTY）。翻转一些标志关闭呼应，然后调用 tcsetattr 来安装更新的结构。当你的程序退出，是好的，放回到原来的。完成。

I have been trying to get getch to work in another program with no success. So I have made the most basic program I can using getch the way I want it to work in the main program.

I have researched the need for noecho, cbreak, initscr and nodelay, I have also tried using newscr() but to no success.

The problem I am having is that the chars aren't being printed to the screen till I hit "enter", when they should be put to the screen every loop. Why is this happening? Also the cursor doesn't return to the left of the screen at the new line. eg.

abc  
   def
      ghi

I have looked for the answer but am stumped again...

#include <stdio.h>
#include <ncurses.h>

int main()
  {
     initscr();cbreak(); noecho();nodelay(stdscr,0);
    char c ;
    while((c=getch())!=EOF){
    putchar(c);}

    return 0;
  }

解决方案

You're not seeing the output because your stdout stream is line buffered.

Your program is getting the individual characters all right; but the output stream is buffering them.

Try fflush(stdout); or switching stdout to unbuffered mode with setbuf(stdout, NULL);.

The problem with disabling buffering is that it's inefficient for bulk data processing when the output isn't a terminal.

You can make it conditional on the standard output being a tty:

if (isatty(fileno(stdout)))  /* #include <unistd.h> */
  setbuf(stdout, NULL);

To return the cursor to the start of the line, you need to put out a carriage return \r. This is because curses' cbreak mode has disabled the ONLCR tty mode (on Output, when sending NL add CR).

If you unconditionally add \r, then it will appear in files when your output is redirected. So again you need some isatty hack.

A much better might be to learn how to use the tcgetattr and tcsetattr functions to precisely control specific tty parameters, if all you want is to do character-at-a-time input without echo, and not actually develop an interactive curses-based program.

Do you really want character-at-a-time input, or just to diable echo? It's easy to disable echo. Call tcgetattr to fill a struct termios with the current settings of file descriptor 0 (if it is a tty). Flip some flags to turn off echoing, then call tcsetattr to install the updated structure. When your program exits, be nice and put back the original one. Done.

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