有没有办法确定终端的背景颜色？

Question

_{（不确定此问题是否属于此处或超级用户）}

我想知道是否有办法确定终端的背景颜色？

就我而言，使用gnome-terminal 它可能很重要，因为它完全由终端应用程序绘制窗口的背景，甚至可能是纯色的其他东西。

Answer 1

这有一个xterm control sequence：

\e]11;?\a

（\e和\a分别是ESC和BEL字符。）

Xterm兼容终端应以相同的顺序回复，问号由X11 colorspec替换，例如，黑色rgb:0000/0000/0000。

Answer 2

我想出了以下内容：

#!/bin/sh
#
# Query a property from the terminal, e.g. background color.
#
# XTerm Operating System Commands
#     "ESC ] Ps;Pt ST"

oldstty=$(stty -g)

# What to query?
# 11: text background
Ps=${1:-11}

stty raw -echo min 0 time 0
# stty raw -echo min 0 time 1
printf "\033]$Ps;?\033\\"
# xterm needs the sleep (or "time 1", but that is 1/10th second).
sleep 0.00000001
read -r answer
# echo $answer | cat -A
result=${answer#*;}
stty $oldstty
# Remove escape at the end.
echo $result | sed 's/[^rgb:0-9a-f/]\+$//'

来源/回购/要点：https://gist.github.com/blueyed/c8470c2aad3381c33ea3

Answer 3

除apparently rxvt-only $COLORFGBG之外，我不知道还有其他任何东西存在。大多数人似乎都是referring to vim does it，即使这是一个有根据的猜测。

Answer 4

一些链接：

• Xterm转义代码：
  • http://www.talisman.org/~erlkonig/documents/xterm-color-queries/
  • https://invisible-island.net/xterm/ctlseqs/ctlseqs.html（动态颜色/请求Termcap / Terminfo字符串）
  • http://thrysoee.dk/xtermcontrol/（xtermcontrol --get-bg）
  • https://gist.github.com/blueyed/c8470c2aad3381c33ea3
  • https://github.com/rocky/bash-term-background/blob/master/term-background.sh
• COLORFGBG环境变量（由Rxvt使用，但其他变量不多...）：
  设置为……<foreground-color>:[<other-setting>:]<background-color> （<other setting>:是可选的），如果{{1，}，{0,1,2,3,4,5,6,8}中的<background-color>有深色背景。
• Vim：
  • 代码：https://github.com/vim/vim/blob/05c00c038bc16e862e17f9e5c8d5a72af6cf7788/src/option.c#L3974
  • How does Vim guess background color on xterm?
• Emacs ...（背景模式）（我认为它使用转义码）
• 相关问题/报告/讨论：
  • Is there a way to determine a terminal's background color?
  • How does Vim guess background color on xterm?
  • https://unix.stackexchange.com/questions/245378/common-environment-variable-to-set-dark-or-light-terminal-background
  • https://bugzilla.gnome.org/show_bug.cgi?id=733423
  • https://github.com/neovim/neovim/issues/2764

例如Neovim issue 2764的一些相关代码段：

/*
 * Return "dark" or "light" depending on the kind of terminal.
 * This is just guessing!  Recognized are:
 * "linux"         Linux console
 * "screen.linux"   Linux console with screen
 * "cygwin"        Cygwin shell
 * "putty"         Putty program
 * We also check the COLORFGBG environment variable, which is set by
 * rxvt and derivatives. This variable contains either two or three
 * values separated by semicolons; we want the last value in either
 * case. If this value is 0-6 or 8, our background is dark.
 */
static char_u *term_bg_default(void)
{
  char_u      *p;

  if (STRCMP(T_NAME, "linux") == 0
      || STRCMP(T_NAME, "screen.linux") == 0
      || STRCMP(T_NAME, "cygwin") == 0
      || STRCMP(T_NAME, "putty") == 0
      || ((p = (char_u *)os_getenv("COLORFGBG")) != NULL
          && (p = vim_strrchr(p, ';')) != NULL
          && ((p[1] >= '0' && p[1] <= '6') || p[1] == '8')
          && p[2] == NUL))
    return (char_u *)"dark";
  return (char_u *)"light";
}

关于COLORFGBG的环境，来自Gnome BugZilla 733423：

  

在我刚刚在linux上尝试过的许多终端中，只有urxvt和konsole对其进行了设置（没有设置：xterm，st，terminology，pterm）。 Konsole和Urxvt使用不同的语法和语义，例如，对我而言，konsole将其设置为“ 0; 15”（即使我使用“ Black on Light Yellow”配色方案-为什么不使用“ default”而不是“ 15”？），而我的urxvt将其设置为“ 0;默认； 15”（实际上是白底黑字-但是为什么要三个字段？）。因此，这两个值都不符合您的要求。

这是我正在使用的一些自己的代码（via）：

def is_dark_terminal_background():
    """
    :return: Whether we have a dark Terminal background color, or None if unknown.
        We currently just check the env var COLORFGBG,
        which some terminals define like "<foreground-color>:<background-color>",
        and if <background-color> in {0,1,2,3,4,5,6,8}, then we have some dark background.
        There are many other complex heuristics we could do here, which work in some cases but not in others.
        See e.g. `here <https://stackoverflow.com/questions/2507337/terminals-background-color>`__.
        But instead of adding more heuristics, we think that explicitly setting COLORFGBG would be the best thing,
        in case it's not like you want it.
    :rtype: bool|None
    """
    if os.environ.get("COLORFGBG", None):
        parts = os.environ["COLORFGBG"].split(";")
        try:
            last_number = int(parts[-1])
            if 0 <= last_number <= 6 or last_number == 8:
                return True
            else:
                return False
        except ValueError:  # not an integer?
            pass
    return None  # unknown (and bool(None) == False, i.e. expect light by default)

Answer 5

您的意思是确定终端背景颜色或设置终端颜色的方法吗？

如果是后者，您可以查询终端的PS1环境变量以获取颜色。

这里有一篇关于设置（以及派生）终端颜色的文章： http://www.ibm.com/developerworks/linux/library/l-tip-prompt/