regular expression matching in java

Question

Here is my example file :

lineone one
RUN lineone two
lineone three
RUN lineone four

I want to select all lines not starting with run, here is how I did it :

^([^RUN])

Is it possible to match all lines not starting with RUN and then append them to the back of the previous line ? like this

lineone one RUN lineone two
lineone three RUN lineone four

Answer 1

If your example is correct you just need to replace "\nRUN" with " RUN".

System.out.println(yourString.replaceAll("\nRUN", " RUN"));

Result:

lineone one RUN lineone two
lineone three RUN lineone four

ideone

Answer 2

use str.startsWith("RUN");