Ruby remove blank lines from a file which include spaces

Question

I am trying to remove blank lines from a file.

My current code is:

 def remove_blank_lines_from_file(file)
   File.write(file, File.read(file).gsub(/^$\n/, '')) 
 end

The above code removes only the empty lines, but I also want to remove the lines which include spaces.

How could I do it?

Answer 1

Since you nevertheless load the whole file into memory, this might be easier to read:

File.write(file, File.readlines(file).reject { |s| s.strip.empty? }.join)

Just remove those lines, containing the spaces only.