Études for Erlang

Étude 10-1: Using ETS

In honor of Erlang’s heritage as a language designed for telephony applications, this étude will set up a small database that keeps track of phone calls.

Part One

Create a file named phone_records.hrl that defines a record with these fields:

• Phone number
• Starting date (month, day, and year)
• Starting time (hours, minutes, and seconds)
• End date (month, day, and year)
• End time (hours, minutes, and seconds)

You may name the record whatever you wish, and you may use any field names you wish.

Part Two

In a module named phone_ets, create an ETS table for phone calls by reading a file. The function that does this will be named setup/1, and its argument will be the name of the file containing the data.

Copy the following text into a file named call_data.csv and save the file in the same directory where you did part one.

650-555-3326,2013-03-10,09:01:47,2013-03-10,09:05:11 415-555-7871,2013-03-10,09:02:20,2013-03-10,09:05:09 729-555-8855,2013-03-10,09:00:55,2013-03-10,09:02:18 729-555-8855,2013-03-10,09:02:57,2013-03-10,09:03:56 213-555-0172,2013-03-10,09:00:59,2013-03-10,09:03:49 946-555-9760,2013-03-10,09:01:20,2013-03-10,09:03:10 301-555-0433,2013-03-10,09:01:44,2013-03-10,09:04:06 301-555-0433,2013-03-10,09:05:17,2013-03-10,09:07:53 301-555-0433,2013-03-10,09:10:05,2013-03-10,09:13:14 729-555-8855,2013-03-10,09:04:40,2013-03-10,09:07:29 213-555-0172,2013-03-10,09:04:26,2013-03-10,09:06:00 213-555-0172,2013-03-10,09:06:59,2013-03-10,09:10:35 946-555-9760,2013-03-10,09:03:36,2013-03-10,09:04:23 ...