如果第一个字段包含点，则提取一行

Question

实际数据是：

Dolibarr                      techpubl        http://techpublications.org/erp
tekstilworks.com              WordPress       tekstilw
wbq.dandydesigns.co         WordPress       cbeqte
WordPress                     cbeqte          http://wbq.dandydesigns.co
WordPress                     cbeqte          http://qbd.dandydesigns.co
WordPress                     cbeqte          http://uqdq.dandydesigns.co
dandydesigns.co               WordPress     cbeqte
stunlockers.info              WordPress         nmmuop

我想得到什么：

 tekstilworks.com              WordPress       tekstilw
 wbq.dandydesigns.co         WordPress       cbeqte
 dandydesigns.co               WordPress     cbeqte
 stunlockers.info              WordPress         nmmuop

Answer 1

使用 awk：

awk '$1 ~ /\./' input-file-here

awk 表达式中的句点必须用反斜杠转义，这样它就不会被视为正则表达式语法。

Answer 2

使用grep相匹配.的第一个字段：

grep '^[^[:blank:]]*\.' file.txt

例子：

$ cat file.txt
Dolibarr                      techpubl        http://techpublications.org/erp
tekstilworks.com              WordPress       tekstilw
wbq.dandydesigns.co         WordPress       cbeqte
WordPress                     cbeqte          http://wbq.dandydesigns.co
WordPress                     cbeqte          http://qbd.dandydesigns.co
WordPress                     cbeqte          http://uqdq.dandydesigns.co
dandydesigns.co               WordPress     cbeqte
stunlockers.info              WordPress         nmmuop

$ grep '^[^[:blank:]]*\.' file.txt
tekstilworks.com              WordPress       tekstilw
wbq.dandydesigns.co         WordPress       cbeqte
dandydesigns.co               WordPress     cbeqte
stunlockers.info              WordPress         nmmuop