Find Unique Characters in a File

Question

I have a file with 450,000+ rows of entries. Each entry is about 7 characters in length. What I want to know is the unique characters of this file.

For instance, if my f

Answer 1

Here's a PowerShell example:

gc file.txt | select -Skip 2 | % { $_.ToCharArray() } | sort -CaseSensitive -Unique

which produces:

D
Y
a
b
o

I like that it's easy to read.

EDIT: Here's a faster version:

$letters = @{} ; gc file.txt | select -Skip 2 | % { $_.ToCharArray() } | % { $letters[$_] = $true } ; $letters.Keys