loop, array and file problem in ruby - ruby

Question

I'm currently learning ruby and here what I'm trying to do:
A script which open a file, make a subsitution, then comparing every lines to each other to see if it exist many times.
So, I tried to work directly with the string, but I didn't find how to do it, so I put every line in an array, and comparing every row.
But I got a first problem.
Here is my code:
#!/usr/bin/env ruby
DOC = "test.txt"
FIND = /,,^M/
SEP = "\n"
#make substitution
puts File.read(DOC).gsub(FIND, SEP)
#open the file and put every line in an array
openFile = File.open(DOC, "r+")
fileArray = openFile.each { |line| line.split(SEP) }
#print fileArray #--> give the name of the object
#Cross the array to compare every items to every others
fileArray.each do |items|
items.chomp
fileArray.each do |items2|
items2.chomp
#Delete if the item already exist
if items = items2
fileArray.delete(items2)
end
end
end
#Save the result in a new file
File.open("test2.txt", "w") do |f|
f.puts fileArray
end
At the end, I only have the name of the array object "fileArray". I print the object after the split, and i've got the same, so I guess the problem is from here. Little help required (if you know how to do this without array, just with the line in the file, answer appreciate too).
Thanks !
EDIT:
So, here's my code now
#!/usr/bin/env ruby
DOC = "test.txt"
FIND = /,,^M/
SEP = "\n"
#make substitution
File.read(DOC).gsub(FIND, SEP)
unique_lines = File.readlines(DOC).uniq
#Save the result in a new file
File.open('test2.txt', 'w') { |f| f.puts(unique_lines) }
Can't figure out how to chomp this.

Answer 1

Deleting duplicate lines in a file:
no_duplicate_lines = File.readlines("filename").uniq
No need to write so much code :)

Answer 2

Modify your code like this:
f.puts fileArray.join("\n")
Alternate way:
unique_lines = File.readlines("filename").uniq
# puts(unique_lines.join("\n")) # Uncomment this line and see if the variable holds the result you want...
File.open('filename', 'w') {|f| f.puts(unique_lines.join("\n"))}

Answer 3

Just a couple of points about the original code:
fileArray = openFile.each { |line| line.split(SEP) }
sets fileArray to a File object, which I suspect wasn't your intention. File#each (the # notation is Ruby convention to describe a particular method on an object of the supplied class) executes your supplied block for each line (it's also available with a synonym: each_line), where a line is defined by default as your OS's end-line character(s).
If you were looking to build an array of lines, then you could just have written
fileArray = openFile.readlines
and if you wanted those lines to be chomped (often a good idea) then that could be achieved by something like
fileArray = openFile.readlines.collect { |line| line.chomp }
or even (since File mixes in Enumerable)
fileArray = openFile.collect { |line| line.chomp }
And one other tiny thing: Ruby tests for equality with ==, = is only for assignment, so
if items = items2
will set items to items2 (and will always evaluate as true)