wc 命令计算额外的字符

Question

cat > file
Amy looked at her watch. He was late. The sun was setting but Jake didn’t care.

wc file
1      16      82 file

有人可以解释为什么wc命令在这种情况下返回 3 个额外的字符吗？

Answer 1

wc多显示 3 个字符，因为您的示例文件包含一个花哨的 Unicode 撇号’（很可能是因为您从浏览器或文本编辑器复制了内容）：

$ cat file
Amy looked at her watch. He was late. The sun was setting but Jake didn’t care.
$ wc file
1      16      82 file

使用纯 ASCII 撇号'：

$ cat file2
Amy looked at her watch. He was late. The sun was setting but Jake didn't care.
$ wc file
1      16      80 file2

wc默认情况下显示^每个手册的字节^数：

每个文件的换行符、单词和字节数

对于字符计数，-m可以使用一个参数：

$ cat file
Amy looked at her watch. He was late. The sun was setting but Jake didn’t care.
$ wc -m file
      80 file.txt

Answer 2

通过管道传输文件以并排xxd查看 ascii 的十六进制输出，这将让您查看是否有您看不到或无法打印的额外字符。

$ cat file
one? and ?two

$ cat file | wc
      1       3      18

$ cat file | xxd
00000000: 6f6e 65e2 808f 2061 6e64 20e2 808f 7477  one... and ...tw
00000010: 6f0a                                     o.