RUBY: Delimited data – text file processing

# Delimited Text data Processing:
# Ruby script to read a pipe (|) delimited file, split each line into an array,
# process individual columns, re-arrange into new array and print to outfile

# Define input and Output files as variables
infile = File::open('../data/CAS_Einecs.txt', 'r')
outfile = File::open('outfile.txt', 'w')

# Iterate through lines of the infile
infile.each do |line|
	
	# splits the line at | delimiter and collects the results into array 'cols'. Whitespace stripped
  	cols = line.split('|').collect {|h| h.strip} 
  	
  	#Convert number to string, so regex can work, then Regex removes leading zeros
 	cas_short = cols[2].to_s.sub(/^[0:]*/,"") 
 	
 	#append the stripped Cas to the array
 	cols.push(cas_short) 
 	 	
 	line = [] #Create a new array into where we can place the columns in any order we like
 	line << cols[5].to_s.chomp #Adds column as array element and removes trailing newline
 	line << cols[1].to_s.chomp
 	line << cols[3].to_s.chomp
 	line << cols[4].to_s.chomp
 	line << cols[2].to_s.chomp
 	
 	# Joins the new array and appends to the outfile.
	outfile.puts(line.join('|')) 
  	end

#Close any open files.\
outfile.close
infile.close

#Success message
puts "Done!"