CODEWITHSUNDEEP
regexunixsed
Zac Sanchez
Zac Sanchez

Reputation: 71

Invert subsitution using regex and sed (unix tools)

I have a column of data of the form tt1234567 however some rows do not fill this criteria and I want to substitute this with a dash (-). Preferably this needs to be done only with unix tools.

at the moment I have sed -e 's/^(tt)/-'

But obviously that replaces everything starting with tt with dash, can i do the inverse command?

Upvotes: 1

Views: 51

Answers (1)

Kent
Kent

Reputation: 195059

Very likely you are looking for this:

sed '/^tt/!s/.*/-/' file

For example:

kent$  cat f
tt123456
;alsjf
tt123456

kent$  sed '/^tt/!s/.*/-/' f
tt123456
-
tt123456

Upvotes: 1

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