CODEWITHSUNDEEP
perlmd5md5-file
Roman Gelembjuk
Roman Gelembjuk

Reputation: 2005

MD5 of a file from stream. Perl

I need to get md5 checksum of a file. But i don't have a file on a disk and i can not save it to disk. I have only a stream (socket) from where i can read a file.

How to calculate MD5 checksum in this case and get it to be same as i would calculate it for file on a disk?

I can read chunks of any size of a stream. Is it possible to get correct MD5 for this case?

I need some instructions of make md5sum from sums of chunks and get same result as

md5sum filetohash.txt

I code with Perl.

Upvotes: 2

Views: 422

Answers (1)

Borodin
Borodin

Reputation: 126732

There is no need to collect the data into a complete file before calculating the checksum. You may add the data in pieces to a Digest::MD5 object, like this

my $md5 = Digest::MD5->new;

while ( my $chunk = read_stream() ) {
    $md5->add($chunk);
}

print $md5->hexdigest, "\n";

Upvotes: 5

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