Echo hash only from shasum

hashsum

Is there a way to get shasum to only print the hash?

I know this can be achieved by piping the output to another program, e.g.

shasum something | cut -d' ' -f1

Is there a way to achieve this only using shasum, without having to pipe the result somewhere else?

Best Answer

No, shasum always prints the filename of the file that it computes the hash for, or - if it reads from standard input.

To avoid the pipe, you could use

perl -MDigest::SHA -e '$s=Digest::SHA->new(); $s->add(<>); print $s->hexdigest(),"\n"' filename

Related Solutions

Bash – How to pipe md5 hash result in shell

You can use the command cut; it allows you to cut a certain character/byte range from every input line. Since the MD5 hash has fixed length (32 characters), you can use the option -c 1-32 to keep only the first 32 characters from the input line:

echo -n test | md5sum | cut -c 1-32

Alternatively, you can tell cut to split the line at the every space and output only the first field: (note the quotes around the space character)

echo -n test | md5sum | cut -d " " -f 1

See the cut manpage for more options.

Trailing space when generating md5

It's 32 characters! The md5sum is adding a linefeed to the end. You can get rid of it like this:

% echo -n string | md5sum|awk '{print $1}'|wc -c
33
% echo -n $(echo -n string | md5sum|awk '{print $1}')|wc -c
32

or you could do it like this:

% echo -n $(md5sum <<< 'string'|awk '{print $1}')|wc -c
32

You can tell when one of the commands is adding a newline because the 32 character string will show up on its own line. If no newline is present it should always show up like this:

[prompt %] echo -n $(md5sum <<< 'string'|awk '{print $1}')
b80fa55b1234f1935cea559d9efbc39a[prompt %]

Best Answer

Related Solutions

Bash – How to pipe md5 hash result in shell

Trailing space when generating md5

Related Question