如何着色editline应用程序的提示

Question

我试图着色由libedit驱动的应用程序的提示,但我的颜色根本没有显示.我在这里做错了什么想法？

#include <iostream>
#include <histedit.h>

char* prompt(EditLine *e)
{
  static char p[] = "\1\033[36m\1:::\1\033[0m\1 ";
  return p;
}

int main(int argc, char* argv[])
{
  EditLine* el = el_init(argv[0], stdin, stdout, stderr);
  el_set(el, EL_PROMPT_ESC, &prompt, '\1');
  el_set(el, EL_EDITOR, "vi");

  while (1)
  {
    int count;
    char const* line = el_gets(el, &count);

    if (count > 0)
      std::cout << line;
  }

  el_end(el);

  return 0;
}

编译

clang++ editline.cc -ledit && ./a.out

并且显示不幸的是只有未着色的提示:

:::     

Answer 1

\1用作停止/开始文字字符，因此这似乎是正确的行为。

\1\033[36m\1:::\1\033[0m\1
|          |   |         |
|          |   |_Start   |_Stop
|          |
|_Start    |_Stop

EL_PROMPT_ESC, char *(*f)(EditLine *), char c 与 EL_PROMPT 相同，但 c 参数表示开始/停止文字提示字符。

     If a start/stop literal character is found in the prompt, the
     character itself is not printed, but characters after it are
     printed directly to the terminal without affecting the state
     of the current line.  A subsequent second start/stop literal
     character ends this behavior.  This is typically used to
     embed literal escape sequences that change the color/style of
     the terminal in the prompt.  0 unsets it.

手册页指出使用0来取消设置颜色，但有点不清楚它们的含义。

也许尝试这样的转义序列：

\1\033[36m:::\033[0m\1

因为\1可能会终止颜色的使用，而\[ ... \]是 bash 中的普通终止符。