Hi all I concatenate files using cat. Each file contains only one csv data. for example, file1 100 file2 200 cat file1 file2 > newfile newfile 100 200 However, is there any way to insert identifier when using cat command? for example, newfile should have file1 100 file2 200 Thanks in advance.

No, but this script solves the problem: # no error checking rm -f newfile for i in file1 file2 do printf "%s " $i >> newfile cat "$i" >> newfile done

Thanks a lot However, I got file1100 file2200 Is there any way to create CSV (comma delimited) or insert space?

I don't know what shell you are using (I'm using ksh), but this printf statement: printf "%s " $i >> newfile has a space after the %s format qualifer, and it works fine. This example uses a pipe symbol instead of the space: printf "%s|" $i >> newfile

Thanks a lot!! You saved my life!