I was asked how I would remove duplicate characters from a string just using RPG. I has been some time since I came up with an all RPG solution, so I accepted the challenge.
The string of data is in a file, TESTFILE, in the field F1. The sample string I used in F1 was:
SELECT F1 FROM TESTFILE ;
I have more than one of these characters in the string: a, b, c, and d. And only one of these: f, g, h, i, j, k, and l. My goal is for a single character of all of these.