Add line after matching a pattern [duplicate]

问题

This question already has answers here:

Using sed, Insert a line above or below the pattern? [duplicate] (4 answers)

Closed 3 years ago.

I have a file say test with following values

Linux
Solaris
Fedora
Ubuntu
AIX
HPUX

How to add a line with system hostname after the line matching AIX? If I do

echo `hostname` >> test

system hostname comes at the last after HPUX.

回答1:

With sed:

sed "s/^AIX$/& $(hostname)/" file

If the line could contain AIX:

sed "s/AIX.*/& $(hostname)/" file

Edit:

To append the hostname after the matching line, try the a(append) command:

sed "/^AIX$/a $(hostname)" file

回答2:

Could you please try following awk and let me know if this helps you.

 awk -v host=$(hostname) '$0 == "AIX"{print $0 RS host;next} 1'  Input_file

EDIT: Adding 1 more solution too here.

awk -v host=$(hostname) '{printf("%s%s\n",$0,$0=="AIX"?RS host:"")}'

来源：https://stackoverflow.com/questions/48002485/add-line-after-matching-a-pattern