Hi there,
I am very new to UNIX,

I have problem. I have file in the following format.
20080101,1234
20080102,2345
20080103,3456
20090101,1245
20090102,1534
....
...

As part ot automating a process, i am suppose to read the first line and process the first cycle(20080101). Upon completion, the first line has to be deleted and then the process should start with the second cycle(the first line after deletion, 20080102).

Please, can some one help.

Wouldn't it be easier to delete the entire input file after you finish processing all lines?

As i said, i am newbie in UNIX. Please suggest how i can do that.

You would use the while command to organize a loop, the read command to read each line, and the rm command to delete the file when done.