Calculate Filename SHA1 With Ruby

Basic usage

Where FILENAME is the filename that you want to calculate

require 'digest/sha1'
Digest::SHA1.hexdigest(FILENAME)

More advanced usage

Save this code as checkhash.rb, usage: checkhash.rb <filename>.

require 'digest/sha1'

# Usage: checkhash.rb <filename>
filename = ARGV.pop
if filename.nil? # if no filename specified then prints help
puts 'Please specify the filename to calculate the hash'
puts "Usage: #{File.basename($PROGRAM_NAME)} FILENAME"
exit
end

# calculating SHA1 hash
def calculate_hash(file)
Digest::SHA1.hexdigest(file)
end

file_hash = calculate_hash(filename)

puts "#{filename}: #{file_hash}"