一个奇怪的文字从工作停止awk命令 [英] An odd text stops awk command from working

问题描述

我用 AWK 命令数与年初相同...行

例如， try1.txt ，该文本是：

  B：C
B：C
 

当我在终端推出以下命令：

 的awk -F'：''$ 1 ==B{一[$​​ 2] ++} END {为（我的）打印我，一个[我]}'try1.txt
 

返回 C 2 这是很好的，因为 B：C 在中出现两次try1.txt 。

我的工具的输出是一个巨大的 output.txt的，不是 try1.txt 要复杂得多。 output.txt的的某些部分包含下列字符：

  ^ @ ^ @ ^ @ ^ @ ^ @ ^ @ ^ @ ^ @ ^ @ ^ @ ^ @ ^ @ ^ @ ^ @ ^ @ ^ @ ^ @ ^ @ ^ @ ^ @ ^ @ ^ @ ^ @ ^ @ ^ @ ^ @ ^ @ ^ @ ^ @ ^ @ ^ @ ^ @ ^ @ ^ @ ^ @ ^ @ ^ 137
 

据系统由系统写入时一个进程被杀死。我与该确定。不过，我意识到它停止 AWK 从运作良好。例如，在 try2.txt 如下：

  B：C
^ @ ^ @ ^ @ ^ @ ^ @ ^ @ ^ @ ^ @ ^ @ ^ @ ^ @ ^ @ ^ @ ^ @ ^ @ ^ @ ^ @ ^ @ ^ @ ^ @ ^ @ ^ @ ^ @ ^ @ ^ @ ^ @ ^ @ ^ @ ^ @ ^ @ ^ @ ^ @ ^ @ ^ @ ^ @ ^ @ ^ 137
B：C
 

命令的awk -F'：''$ 1 ==B{一[$​​ 2] ++} END {为（我的）打印我，一个[I] }'try2.txt 收益的C 1 。这就是说，它停止时它满足了奇数行 ^ @ ^ @ ^ @ ^ @ ^ @ 。

我不知道该如何防止系统写奇数行 ^ @ ^ @ ^ @ ^ @ ^ @ ，所以没有人知道如何修改 AWK 命令解决方法吗？

编辑：看来， ^ @ 我发现我的 output.txt的是不正常的字符 ^ @ 。以下是的屏幕截图output.txt的的一部分，在的Emacs ，其中有麻烦显示：

编辑：的建议，我运行 XXD try2.txt ，它给了：

  0000000：6220 3A20 0000 630A 0000 0000 0000 0000 B：C ...........
0000010：0000 0000 0000 0000 0000 0000 0000 0000 ................
0000020：0000 0000 0000 0000 0031 3337 0a62 203A ......... 137.b：
0000030：2063 0A
 

解决方案

^ @ 可能是一个二进制的0 / NUL字符的重新presentation：

$头-C10的/ dev /零> 10zero
$猫-v 10zero
^ @ ^ @ ^ @ ^ @ ^ @ ^ @ ^ @ ^ @ ^ @ ^ @ $

一些面向文本的实用程序可能将此视为文件的末尾。

所以，因为输入文件是一个二进制文件，你应该有更多的运气首先提取它的文本字符串，只是这些操作：

  $字符串try1.txt | awk的-F'：''$ 1 ==B{一[$​​ 2] ++} END {为（我的）打印我，一个[I]}
   C 2
$
 

的字符串命令手册页。（BTW注意，当你谷歌男人的字符串 - 你可能会得到你可能没有讨价还价;-)一些图片）

---

请注意为好奇 - 究竟我重新创建OP的try1.txt文件我的机器上这样的：

• 捕捉问题的 XXD 输出到一个名为try1.xxd
文本文件

• XXD -r try1.xxd＆GT; try1.txt 反转正常 XXD 操作。

I use awk command to count lines with same beginning...

For instance, in try1.txt, the texts are:

b : c
b : c

When I launch the following command in a terminal:

awk -F ' : ' '$1=="b"{a[$2]++} END{for (i in a) print "  ", i,a[i]}' try1.txt

it returns c 2 which is good, because b : c appears twice in try1.txt.

The output of my tool is a huge output.txt, much more complicated than try1.txt. Some part of output.txt contains the following characters:

^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^137

It is systematically written by the system when a process is killed. I am OK with that. However, I realize that it stops awk from working well. For example, in try2.txt as follows:

b : c
^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^137
b : c

The command awk -F ' : ' '$1=="b"{a[$2]++} END{for (i in a) print " ", i,a[i]}' try2.txt returns c 1. That said, it stopped when it met the odd line ^@^@^@^@^@.

I don't know how to keep the system from writing the odd line ^@^@^@^@^@, so does anyone know how to amend awk command to workaround?

Edit: It seems that the ^@ I found in my output.txt is not normal characters ^@. The following is a part of screen shot of output.txt, displayed in Emacs, which has trouble:

Edit: As suggested, I run xxd try2.txt, it gave:

0000000: 6220 3a20 630a 0000 0000 0000 0000 0000  b : c...........
0000010: 0000 0000 0000 0000 0000 0000 0000 0000  ................
0000020: 0000 0000 0000 0000 0031 3337 0a62 203a  .........137.b :
0000030: 2063 0a  

解决方案

^@ is likely a representation of a binary 0 / NUL character:

$ head -c10 /dev/zero > 10zero
$ cat -v 10zero 
^@^@^@^@^@^@^@^@^@^@$ 

Some text-oriented utilities may treat this as an end of file.

So since your input file is a binary file, you should have more luck extracting the text strings from it first and just operating on those:

$ strings try1.txt | awk -F ' : ' '$1=="b"{a[$2]++} END{for (i in a) print "  ", i,a[i]}'
   c 2
$

The strings command man page. (btw watch out when you google "man strings" - you might get some images you might not have bargained for ;-) )

---

Note for the curious - I recreated the OP's try1.txt file exactly on my machine thus:

• capture the xxd output on the question to a text file called try1.xxd
• xxd -r try1.xxd > try1.txt reverses the normal xxd operation.

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