如何使用 awk 打印两个模式之间的所有内容

Question

我可以使用这个 awk 命令打印两种模式之间的所有内容：

awk '/'$1'/{a=1} a; /PATTERN2/{a=0}' ~/the/path/to/file.txt

我需要打印 PATTERN1 之间的所有内容以及 PATTERN2 之前的所有内容（始终以 # 开头的一行。

实际上，这些模式是诸如#france 和#germany 之类的主题标签。

例如文件包含：

#france
France is a European country.
It's capital city is Paris.
One of its biggest cities is Lyon.

#germany
Germany is a European country.
It's capital city is Berlin.
One of its biggest cities is Munich.

调用#france后我想打印的内容：

#france
France is a European country.
It's capital city is Paris.
One of its biggest cities is Lyon.

如果我能以其他颜色（如蓝色或红色）显示图案，那就太好了。

Answer 1

您可以使用基于匹配您要打印的部分设置标志的模式：

awk -v cc="#france" '/^#/{f=($1==cc)} f' file
#france
France is a European country.
It's capital city is Paris.
One of its biggest cities is Lyon.

或者：

awk -v cc="#germany" '/^#/{f=($1==cc)} f' file
#germany
Germany is a European country.
It's capital city is Berlin.
One of its biggest cities is Munich.

如果没有匹配，它将永远不会开始打印，并且只会在遇到另一个 #hashtag 时停止打印。

---

如何给图案着色？

您将使用ANSI Escape Codes，如This Post。这取决于您的终端设置是否支持 ANSI 代码。大多数都这样做。

例子：

awk -v cc="#germany" '/^#/{
    f=($1==cc)
    if (f) printf("\033[0;31m%s\033[0m\n", $0)
    next 
    } 
    f' file

打印（在我的终端上）：

#germany                             # red on black
Germany is a European country.       # green on black...
It's capital city is Berlin.         # green is the default color
One of its biggest cities is Munich.

Answer 2

如果条目之间总是有空行，您可以通过将RS 设置为空字符串来利用GNU AWK 的段落模式，让file.txt 内容为

#france
France is a European country.
It's capital city is Paris.
One of its biggest cities is Lyon.

#germany
Germany is a European country.
It's capital city is Berlin.
One of its biggest cities is Munich.

然后

awk 'BEGIN{RS=""}/^#france/' file.txt

输出

#france
France is a European country.
It's capital city is Paris.
One of its biggest cities is Lyon.

解释：RS="" 导致 GNU AWK 将段落视为行。我只是过滤以 (^) #france 开头的行。

（在 GNU Awk 5.0.1 中测试）

Answer 3

仅使用您展示的示例，您可以尝试遵循awk 代码。我使用RS（记录分隔符）作为段落模式并检查行是否从特定字符串开始，然后打印整个段落。

awk -v RS="" '$0~/^#france\n/' Input_file