Example:
file contains the following:
lebnassvm0a-dr test1 /vol/test1
lebnassvm0a-dr test2 /test2
lebnassvm0a-dr test3 /test3
stgtestsvm1-dr test21 /test21
stgtestsvm1-dr test22 /test22
stgtestsvm1-dr test23 /test23
I want to find the "-dr" and replace with "-drt" and insert the full string in front of the existing, like this:
lebnassvm0a-drt lebnassvm0a-dr test1 /vol/test1
lebnassvm0a-drt lebnassvm0a-dr test2 /test2
lebnassvm0a-drt lebnassvm0a-dr test3 /test3
stgtestsvm1-drt stgtestsvm1-dr test21 /test21
stgtestsvm1-drt stgtestsvm1-dr test22 /test22
stgtestsvm1-drt stgtestsvm1-dr test23 /test23
>Solution :
What I would do:
$ sed -E 's/^([^-]+-dr)/\1t \1/' file
lebnassvm0a-drt lebnassvm0a-dr test1 /vol/test1
lebnassvm0a-drt lebnassvm0a-dr test2 /test2
lebnassvm0a-drt lebnassvm0a-dr test3 /test3
stgtestsvm1-drt stgtestsvm1-dr test21 /test21
stgtestsvm1-drt stgtestsvm1-dr test22 /test22
stgtestsvm1-drt stgtestsvm1-dr test23 /test23
The regular expression matches as follows:
| Node | Explanation |
|---|---|
^ |
the beginning of the string anchor |
( |
group and capture to \1: |
[^-]+ |
any character except: - (1 or more times (matching the most amount possible)) |
-dr |
‘-dr’ |
) |
end of \1 |