sha1_file

  • There are generally two different ways in Ruby to generate a cryptographic hash of a file. The first and easiest way is to use File.read to read the entire file contents into memory. We can then use the same SHA1.hexdigest method on the contents to generate the hash.

    PHP

    print sha1_file("my_file.jpg");
// => 5de1a26c24b0d176c6cafd11bf1f03017bcc767b

    Ruby

    require "digest"
 
print Digest::SHA1.hexdigest(File.read("my_file.jpg"))
# => 5de1a26c24b0d176c6cafd11bf1f03017bcc767b

    The code above works for many cases but for larger files, there’s a risk of consuming large amounts of memory. For these cases, we can initialize a new digest with Digest::SHA1.new and then read the file in smaller chunks, incrementally building the digest with SHA1#update.

    Ruby

    require "digest"
 
digest = Digest::SHA1.new
File.open("my_file.jpg", "r") do |f|
  digest.update f.read(8192) until f.eof
end
 
print digest.hexdigest
# => 5de1a26c24b0d176c6cafd11bf1f03017bcc767b

    see also

← sha1 shuffle →

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