I am tryin to figure out how to extract interested text from file

example.txt

blah blah
blah a: child1
blah a: child2
blah b: parent1
blah blah
blah ....
blah a: child21
blah a: child22
blah a: child23
blah b: parent2


this kinda text repeats .. number of children is not fixed they vary randomly..

the goal is to end up with a file whihc has all the children names under the related parent name.

for this example, what output are you expecting?

Expected output:

In a text file:

Parent1
child1
child2

parent2
child21
child22
child23

parent3

child31
child32
....

***************************************

In the file 'a' and 'b' are the identifiers for the parent and children.

Thanks to you.

I thought of doing something like:

step 1: Grep for parents and then after I get the list of parents {may be in an array}

step 2: I can grep for children with a condition which checks if I hit the first parent from the previously obtained list. When I hit the first parent then save the child list to a text file with the parent name on it.

step 3: Again proceed for the next ones by keeping every thing in a for loop and update the text file every time.


If this algorithm sounds good then the point I am stuck with is step 2.

can you help me out there/ or with any other alternative way.

May be a regexpression can do it easily.

A command like:

grep expression textfile.txt | tee newfile.txt

where expresion will say list me all lines which has 'a:' or 'b:' in it and now the newfile.txt will have all my interested lines.

with the parent names below their child names
{I some how have to get rid of the extra text like blah blah }

Can you point me how the regexpression should be like

grep [ab] [:] textfile.txt | tac | cut -d":" f2 | tee result.txt


Thanks Yogesh and other who viewed/etc my post .

Cheers,
Raj

is there any command to convert

figure to text

for eg: 05032009 to 5March2009

@ haris this is the third time you post the very same question on someone else's post. I have replied to your problem here:
Parsing log files, displaying logs between specific dates