linux - 从日志文件中搜索并打印特定数字

Question

我有一个具有这种结构的log.text 文件:

user                session             login_time          application         database            db_connect_time     request             request_time        connection_source   connection_ip       request_state
+-------------------+-------------------+-------------------+-------------------+-------------------+-------------------+-------------------+-------------------+-------------------+-------------------+-------------------
 admin                                 0                   9                                                           0 none                                  0 Not Requested*      a00:bf32::                    
 admin                         989855740                1335 DRRDEVMH            DRRPRODB                           1201 none                                  0 Not Requested       a00:8a45::                    
 admin                        1768947706                 932 test                test                                916 none                                  0 Not Requested       a00:94b6::                    

 WARNING - 1241024 - Possible string truncation in column 1.
 WARNING - 1241028 - Output column defined with warnings.
 WARNING - 1241024 - Possible string truncation in column 9.
 WARNING - 1241028 - Output column defined with warnings.
 WARNING - 1241024 - Possible string truncation in column 10.
 WARNING - 1241028 - Output column defined with warnings.
 OK/INFO - 1241044 - Records returned: [3].

我们可以在 log.txt 的最后一行看到一个字符串 Records returned: [3]。数字 3 是我的目标，提取该数字(在本例中为 3)我想在单独的文件中打印下一行。

The total records returned = 3

我正在使用:

sed -n 's@^.*Records returned.*[\(.*\)$@\1@p' log.txt > out.txt

但它没有给出结果。请问我在这里犯了什么错误？

Answer 1

你需要转义[，试试这个

sed -n 's@^.*Records returned.*\[\(.*\)\].*$@\1@p' log.txt > out.txt

编辑
如果你想打印出这样的字符串

The total records returned = 3

只需在 \1 之前添加 The total records returned =，因此脚本将是

sed -n 's@^.*Records returned.*\[\(.*\)\].*$@The total records returned = \1@p' log.txt > out.txt