Having trouble saving to file in Ruby - ruby

Question

Hi I have a simple form that allows a user to input a name, their gender and a password. I use Digest::MD5.hexdigest to encrypt the input. Once I have the encrypted input eg, d1c261ede46c1c66b7e873564291ebdc, I want to be able to append this to a file I have already created. However every thing I have tried just isn't working. Can anyone please help and thank you in advance. Here is what I have:
input = STDIN.read( ENV["CONTENT_LENGHT"] )
puts "Content-type: text/html \n\n"
require 'digest/md5'
digest = Digest::MD5.hexdigest(input)
f = File.open("register.txt", "a")
f.write(digest)
f.close
I have also tried this with no luck:
File.open("register.txt", "a") do |f|
f.puts(digest)
end

Answer 1

If the code is verbatim then I think you have a typo in the first line: did you mean CONTENT_LENGHT or is it a typo? ENV[] will return a string if the variable is set, which will upset STDIN#read. I get TypeError: can't convert String into Integer. Assuming the typo, then ENV[] returns nil, which tells STDIN#read to read until EOF, which from the console means, I think, Control-Z. That might be causing a problem.
I suggest you investigate by modifying your script thus:
read_length = ENV["CONTENT_LENGTH"].to_i # assumed typo fixed, convert to integer
puts "read length = #{read_length}"
input = STDIN.read( read_length )
puts "input = #{input}"
puts "Content-type: text/html \n\n" # this seems to serve no purpose
require 'digest/md5'
digest = Digest::MD5.hexdigest(input)
puts "digest = #{digest}"
# prefer this version: it's more idiomatically "Rubyish"
File.open("register.txt", "a") do |f|
puts "file opened"
f.puts(digest)
end
file_content = File.read("register.txt")
puts "done, file content = #{file_content}"
This works on my machine, with the following output (when CONTENT_LENGTH set to 12):
read length = 12
abcdefghijkl
input = abcdefghijkl
Content-type: text/html
digest = 9fc9d606912030dca86582ed62595cf7
file opened
done, file content = 6cfbc6ae37c91b4faf7310fbc2b7d5e8
e271dc47fa80ddc9e6590042ad9ed2b7
b0fb8772912c4ac0f13525409c2b224e
9fc9d606912030dca86582ed62595cf7