UNIX for Dummies Questions & Answers

Hi all, i have a text file similar to below

Code:

A1
A2
A3
B1 ... .... *** # first occurance
B1 ... .... *** # second occurance 
B1 ... .... *** # third occurance

My desired output is

Code:

B1 ... .... *** # second occurance
B1 ... .... *** # third occurance

I want to remove the first line that is after the A's.

I have a primitive method

Code:

 /cat myfile | grep B >> desired_file

I only managed to remove the lines beginning with A. What can i next do to remove the first line from the results of grep-ping B?

Hi,
Hoping that only fourth line has to be removed, try out the given code below.

sed -e '4s/B1//g' myfile |grep "B1"

Hope this solves your problem.

Or 'grep B myfile | tail +1' to omit the first occurrence (which is spelled with two r:s and two e:s and no a)

You can also use csplit on the result of the grep-ped file

csplit (options) input-file-name 2

will produce two output files, one containing only the first record and the second file will contain the other stuff. Essentially you're splitting the file at line 2.

Use the options to specify a prefix and/or suffix if you want.

The files resulting from the csplit can be cat-ed together to recreate the file being split. Moreover, csplit leaves your input file intact.