You don't show us the code you've already written, and where you have problems with that code. This makes it somewhat hard for us to help you better.

You also don't tell us the format of the second file and what should happen if there are duplicate keys in your key column.

That said, maybe you want join - join two files according to a common key, or part - split up files according to column value or the technique used in the two programs.

1. open file ("file1") to read;
2. read a line;
3. split it in 3 parts on white space;
4. save results in an array;
   1. open the file name given by last array element ("pqr");
   2. write the array content to the file;
   3. close the file.
5. repeat 2 until whole file is read;
6. close the file.

Alternatively, if the last element of the lines being does not ever change, you would need to split the line only once and could open and close the file handle being written to outside of the loop, and read & write in consecutive statements.

Another variation could be is to save the file being read in a variable and write the value of that variable after everything has been read.

OK -- now we're getting somewhere. What Perl code have you written to implement that algorithm?

Alex / talexb / Toronto

"Groklaw is the open-source mentality applied to legal research" ~ Linus Torvalds

parv isn't the OP. :P