Question

how can I create a flat file in ruby?

Flat file is there each letter is placed at a specific column number in the file.

So for example if I am reading some values from the DB:

Name         Class
-------------------
one          A
two          English
three        Math
four         Science

and I want to make a flat file out of it where names are to be between columns 1 to 10 and class is to be between columns 20 to 30. How can I make that file? I know how to write to a file but don’t know how to write to a file…with specified columns…?

I tried sprintf from Mladen Jablanović answer

C:\>ruby parse.rb
2342342423
SOMETHING
2342
01/03/2010SDSDFS
234234
sprintf on array        2342342423SOMETHING 2342      01/03/2010SDSDFS234234

Answer 1

You can use sprintf (or its equivalent String#%) with padded fields:

"%-10s%-10s%-10s" % ['two', '', 'English']
#=> "two                 English   "