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C 块信号

[英]C Block signals

原文 2022-01-27 09:59:48 5 1 c/ shell/ signals

I am trying to write a shell-like application and struggle with the signal blocking.我正在尝试编写一个类似 shell 的应用程序并与信号阻塞作斗争。 I want to disable/block some signals like SIGINT or SIGQUIT so when user press Ctrl+C or Ctrl+\, nothing will happen.我想禁用/阻止一些信号，如 SIGINT 或 SIGQUIT 所以当用户按下 Ctrl+C 或 Ctrl+\ 时，什么都不会发生。

I have done some research and was able to do that by using either signal(SIGQUIT, SIG_IGN) or sigaction() .我已经做了一些研究，并且能够通过使用signal(SIGQUIT, SIG_IGN)或sigaction()来做到这一点。

My problem is that the signal is not totally blocked.我的问题是信号没有被完全屏蔽。 When I pressed Ctrl+\ several times inside my application, it will not exit as expected but will also display this ^\ .当我在我的应用程序中多次按下 Ctrl+\ 时，它不会按预期退出，但也会显示这个^\ 。

Also, because I use an readline() to catch the input of the user, when I use Ctrl+\ and press Enter, there is a strange newline.另外，因为我使用readline()来捕获用户的输入，所以当我使用 Ctrl+\ 并按 Enter 时，会出现一个奇怪的换行符。

1 个解决方案

Seems like you blocked signals properly.好像你正确地阻止了信号。 As you disabled the signal, when you press Ctrl+\ then your terminal sends it to your application.当您禁用信号时，当您按下Ctrl+\时，您的终端会将其发送到您的应用程序。 The same way as a is sent when you press "A" on your keyboard, but unlike "A", Ctrl+\ does not generate any printable character, your terminal can not print it directly.与在键盘上按“A”时发送a方式相同，但与“A”不同的是， Ctrl+\不会生成任何可打印字符，您的终端无法直接打印。 ^\ is basically the special notation of that non-printable character. ^\基本上是该不可打印字符的特殊符号。 You will also get that "character" in readline() results, that is the strange thing are seeing.您还将在readline()结果中得到那个“字符”，这是奇怪的事情。