为什么此命令不根据 uniq 计数进行排序？

Question

我在日志中有类似于以下内容的行：

2015/11/02-07:55:39.735 INFO failed with ERR_AUTHORIZATION_REQUIRED.  (10.10.10.11:61618) is not a trusted source.
2015/11/02-07:55:40.515 INFO failed with ERR_AUTHORIZATION_REQUIRED.  (10.10.10.11:51836) is not a trusted source.
2015/11/02-07:55:39.735 INFO failed with ERR_AUTHORIZATION_REQUIRED.  (10.10.10.10:61615) is not a trusted source.
2015/11/02-07:55:40.515 INFO failed with ERR_AUTHORIZATION_REQUIRED.  (10.10.10.10:51876) is not a trusted source.
2015/11/02-07:55:39.735 INFO failed with ERR_AUTHORIZATION_REQUIRED.  (10.10.10.10:61614) is not a trusted source.
2015/11/02-07:55:39.735 INFO failed with ERR_AUTHORIZATION_REQUIRED.  (10.10.10.15:61614) is not a trusted source.
2015/11/02-07:55:39.735 INFO failed with ERR_AUTHORIZATION_REQUIRED.  (10.10.10.15:61618) is not a trusted source.
2015/11/02-07:55:39.735 INFO failed with ERR_AUTHORIZATION_REQUIRED.  (10.10.10.15:61613) is not a trusted source.

所以，我尝试了以下命令来获取每个 uniq IP 的计数，排序：

grep ERR_AUTHORIZATION_REQUIRED file.log | awk '{print $6}' | cut -s -d ':' -f1 | tr -d '(' | sort | uniq -c

我得到的输出类似于以下内容：

3 10.10.10.10
2 10.10.10.11
3 10.10.10.15

所以这就像在应用之前对 IP 进行排序uniq -c（这在给定命令的情况下是有意义的），但是如果我交换uniq和sort命令，每个 IP 都会打印1.

Answer 1

从uniq联机帮助页：

DESCRIPTION
     Discard all but one of successive identical lines from INPUT (or standard input), writing to OUTPUT (or standard output).

这里的关键词是“成功”。它不会在流中的任何点搜索重复项，只会搜索紧随其后的那些。排序强制所有重复项彼此相邻，因此可以删除（并计算）它们。