使用awk或sed或cut过滤文本文件？

Question

我正在努力解决这个问题。

$ cat test.txt  
server1
ec2-xx.xx.xx.xxus-west-2.compute.amazonaws.com
Search
ec2-xx-xx-xx-xx.us-west-2.compute.amazonaws.com
Web
ec2-xx-xx-xx-xx.us-west-2.compute.amazonaws.com
Web
ec2-xx-xx-xx-xx.us-west-2.compute.amazonaws.com
server2
ec2-xx.xx-xx-xx.us-west-2.compute.amazonaws.com
loaddb
ec2-xx-xx-xx-xx.us-west-2.compute.amazonaws.com
ec2dd
ec2-xx-xx-xx-xx.us-west-2.compute.amazonaws.com
server2
ec2-xx.xx-xx-xx.us-west-2.compute.amazonaws.com
loaddb
ec2-xx-xx-xx-xx.us-west-2.compute.amazonaws.com

我需要这样的输出：

$ cat test.txt
server1:ec2-xx.xx.xx.xxus-west-2.compute.amazonaws.com  
Search:ec2-xx.xx.xx.xxus-west-2.compute.amazonaws.com  
Web:ec2-xx.xx.xx.xxus-west-2.compute.amazonaws.com  
Web:ec2-xx.xx.xx.xxus-west-2.compute.amazonaws.com  
server2:ec2-xx.xx.xx.xxus-west-2.compute.amazonaws.com  
loaddb:ec2-xx.xx.xx.xxus-west-2.compute.amazonaws.com  
ec2dd:ec2-xx.xx.xx.xxus-west-2.compute.amazonaws.com  
server2:ec2-xx.xx.xx.xxus-west-2.compute.amazonaws.com  
loaddb:ec2-xx.xx.xx.xxus-west-2.compute.amazonaws.com

Answer 1

使用sed：

$ sed 'N;s/\n/:/' test.txt
server1:ec2-xx.xx.xx.xxus-west-2.compute.amazonaws.com
Search:ec2-xx-xx-xx-xx.us-west-2.compute.amazonaws.com
Web:ec2-xx-xx-xx-xx.us-west-2.compute.amazonaws.com
Web:ec2-xx-xx-xx-xx.us-west-2.compute.amazonaws.com
server2:ec2-xx.xx-xx-xx.us-west-2.compute.amazonaws.com
loaddb:ec2-xx-xx-xx-xx.us-west-2.compute.amazonaws.com
ec2dd:ec2-xx-xx-xx-xx.us-west-2.compute.amazonaws.com
server2:ec2-xx.xx-xx-xx.us-west-2.compute.amazonaws.com
loaddb:ec2-xx-xx-xx-xx.us-west-2.compute.amazonaws.com 

此方法使用两个sed命令：

• N从文件中读取第二行并将其附加到模式空间。这样，模式空间总是有两条连续的行。

• s/\n/:/从模式空间中的两行之间删除换行符，并用冒号替换它。

使用awk：

$ awk 'NR%2==1{name=$1;next} {print name ":" $0;}' test.txt
server1:ec2-xx.xx.xx.xxus-west-2.compute.amazonaws.com
Search:ec2-xx-xx-xx-xx.us-west-2.compute.amazonaws.com
Web:ec2-xx-xx-xx-xx.us-west-2.compute.amazonaws.com
Web:ec2-xx-xx-xx-xx.us-west-2.compute.amazonaws.com
server2:ec2-xx.xx-xx-xx.us-west-2.compute.amazonaws.com
loaddb:ec2-xx-xx-xx-xx.us-west-2.compute.amazonaws.com
ec2dd:ec2-xx-xx-xx-xx.us-west-2.compute.amazonaws.com
server2:ec2-xx.xx-xx-xx.us-west-2.compute.amazonaws.com
loaddb:ec2-xx-xx-xx-xx.us-west-2.compute.amazonaws.com 

注意：

• NR%2==1{name=$1;next}

  这将读取第一个和所有后续的奇数 - 编号行，并将第一个字段分配给变量name。然后跳过其余的命令并跳转到next行重新开始。

• print name ":" $0

  在偶数行上，打印名称，冒号和当前行。

使用纯shell

while read name; read line
do
        printf "%s:%s\n" "$name" "$line"
done <test.txt

此处，一行从text.txt读入变量name，下一行读入变量line。然后在它们之间打印这两个。

Answer 2

您只需使用paste命令

即可

paste -d: - - < file

通过Perl，

perl -pe 's/\n/:/g if $.%2==1' file

Perl中的

$.与awk中的NR类似。所以它只需要奇数行，并且仅在特定行上用:替换换行符。

Answer 3

此awk可能会这样做，但如果您不完全理解，请小心getline。

awk '{a=$1;getline;print a":"$1}' file
server1:ec2-xx.xx.xx.xxus-west-2.compute.amazonaws.com
Search:ec2-xx-xx-xx-xx.us-west-2.compute.amazonaws.com
Web:ec2-xx-xx-xx-xx.us-west-2.compute.amazonaws.com
Web:ec2-xx-xx-xx-xx.us-west-2.compute.amazonaws.com
server2:ec2-xx.xx-xx-xx.us-west-2.compute.amazonaws.com
loaddb:ec2-xx-xx-xx-xx.us-west-2.compute.amazonaws.com
ec2dd:ec2-xx-xx-xx-xx.us-west-2.compute.amazonaws.com
server2:ec2-xx.xx-xx-xx.us-west-2.compute.amazonaws.com
loaddb:ec2-xx-xx-xx-xx.us-west-2.compute.amazonaws.com

这是一种更好的方法：

awk 'ORS=NR%2?":":RS' file
server1:ec2-xx.xx.xx.xxus-west-2.compute.amazonaws.com
Search:ec2-xx-xx-xx-xx.us-west-2.compute.amazonaws.com
Web:ec2-xx-xx-xx-xx.us-west-2.compute.amazonaws.com
Web:ec2-xx-xx-xx-xx.us-west-2.compute.amazonaws.com
server2:ec2-xx.xx-xx-xx.us-west-2.compute.amazonaws.com
loaddb:ec2-xx-xx-xx-xx.us-west-2.compute.amazonaws.com
ec2dd:ec2-xx-xx-xx-xx.us-west-2.compute.amazonaws.com
server2:ec2-xx.xx-xx-xx.us-west-2.compute.amazonaws.com
loaddb:ec2-xx-xx-xx-xx.us-west-2.compute.amazonaws.com