I have this line "%is xxx = 123" in a program. I want to use sed command to replace it with something else but part of this line is not the same all the time. For example, it could be "%is xxx = 456" (and these three number change all the time)

I have:

sed 's/%is xxx = 123/my replacement/g' programfile > newfile

What modify I need to do to have it works wether it /%is xxx = 123, /%is xxx = 456 or so? I know ^ this begin of the line and $ is end of the line

sed 's/%is xxx = ***$/my replacement/g' programfile > newfile

Please advise!

Thanks!

Will this help?

What happen if the data is
$ cat tmp
%is xxx = 123 be 123
How to code it so it will ignore 123 be 123. I know that "%is xxx = " is the exact pattern everytime the rest of the line is unknown
using the code below I will get
$ sed 's/^\(%is xxx = \)[0-9]*\( *.*\)$/\11234\2/g' tmp

%is xxx = 1234 be 123

I am only interested to get:
%is xxx = 1234

Remove \2