Shell Programming and Scripting

I have a file , the file content will be modified regularly , its structure as below, the lines are begins with "A" and "B" .

#vi file1

Code:

 
this is testing file 
A  aaaaa
B  bbbbb
A  ccccc 
B  ddddd
A  eeeee 
B  fffff 
A  ggggg 
B  hhhhh

I would like to have a script to use the information in file1 to generate another file , so that when run the script , it will generate another file as below format , would advsie what can I do ? thanks

#vi file2

Code:

my_stringbbbbb aaaaa
my_stringddddd ccccc
my_stringfffff eeeee
my_stringhhhhh ggggg

Is this a homework assignment?

Is my_string a constant, or is it a parameter to your script?

What have you tried to solved this problem?

Are the blank line and the this is a testing file in file1? Are the A and B lines always in that order? Are there ever other lines between the A and B lines?

thanks for your help

Is this a homework assignment? ==> this is not homework assignment .
Is my_string a constant, or is it a parameter to your script? ==> my_string is a constant
What have you tried to solved this problem? ==> sorry , I am new to script writing . I tried read something but still not find any idea.

Are the blank line and the this is a testing file in file1 ? ==> in file1 , there are blank line and have other line not begins with "A" or "B" .
Are the A and B lines always in that order? ==> yes , A then B
Are there ever other lines between the A and B lines? ==> No other lines.


Instead of generating the file2 after each time run the script , is it possible to append the new lines to file2 ? for example , if there is the following new lines in file1 .

Code:

A  iiiii
B  jjjjj

then append the following new line to file2 rather than re-generate file2 ?

Code:

 
my_stringjjjjj iiiii

In the 27 threads that you have started, you used to show that you were putting some effort into solving the problems that you raised. Lately, you do not show any effort on your own. We are happy to help you learn how to use the tools provided by UNIX and Linux systems, but we are not here to do your work for you and we are not here to act as your unpaid programming staff.

There are many examples of awk scripts in these forums that solve similar problems. Please show us what you have tried or, at least, tell us what research you have done and where you are stuck.