The same string will generate different md5sums by python and md5sum tool.

hongy...@gmail.com

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Oct 12, 2021, 3:35:35 AM10/12/21

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For short, as shown below:

$ md5sum <<< 'TASCJO3RJMVKWDJKXLZM'
e1b8fa8fe09c295811063bb76cefc337 -

$ ipython
In [1]: from hashlib import md5

In [2]: my_str='TASCJO3RJMVKWDJKXLZM'

In [3]: md5(my_str.encode('utf-8')).hexdigest()
Out[3]: 'e9032994dabac08080091151380478a2'

Any hints for this behavior?

Regards,
HZ

Ben Bacarisse

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Oct 12, 2021, 6:25:43 AM10/12/21

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>>> md5("TASCJO3RJMVKWDJKXLZM\n".encode('utf-8')).hexdigest()
'e1b8fa8fe09c295811063bb76cefc337'

--
Ben.

hongy...@gmail.com

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Oct 12, 2021, 8:03:58 AM10/12/21

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Thank you for pointing this out. I confirmed it with the following command:

$ cat -A <<< 'TASCJO3RJMVKWDJKXLZM'
TASCJO3RJMVKWDJKXLZM$

But how to supply string for md5sum without '\n'?

HZ

hongy...@gmail.com

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Oct 12, 2021, 8:19:28 AM10/12/21

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I see. Here it is:

$ echo -n 'TASCJO3RJMVKWDJKXLZM' | md5sum
e9032994dabac08080091151380478a2 -

HZ

hongy...@gmail.com

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Oct 12, 2021, 8:21:02 AM10/12/21

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So, it seems that the `<<<' will also append `\n' at the end of the string.

HZ

David W. Hodgins

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Oct 12, 2021, 9:08:30 AM10/12/21

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$ echo -n 'TASCJO3RJMVKWDJKXLZM' |md5sum
e9032994dabac08080091151380478a2 -

Regards, Dave Hodgins

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Change dwho...@nomail.afraid.org to davidw...@teksavvy.com for
email replies.

William Unruh

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Oct 12, 2021, 9:12:10 AM10/12/21

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From man bash

Here Strings
A variant of here documents, the format is:

[n]<<<word

The word undergoes tilde expansion, parameter and variable expansion, command substitu-
tion, arithmetic expansion, and quote removal. Pathname expansion and word splitting are
not performed. The result is supplied as a single string, with a newline appended, to
the command on its standard input (or file descriptor n if n is specified).

Note the second last line.

Christian Weisgerber

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Oct 12, 2021, 9:30:08 AM10/12/21

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On 2021-10-12, hongy...@gmail.com <hongy...@gmail.com> wrote:

> But how to supply string for md5sum without '\n'?

$ printf '%s' 'TASCJO3RJMVKWDJKXLZM' | md5
e9032994dabac08080091151380478a2

--
Christian "naddy" Weisgerber na...@mips.inka.de

Ed Morton

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Oct 12, 2021, 10:15:21 AM10/12/21

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Right, it's saving a string into a temp file and than using that as the
input to the command so, since every line in a POSIX text file must end
in `\n`, `<<<` has to add one. It's equivalent to manually writing:

tmp=$(mktemp) &&
printf '%s\n' 'TASCJO3RJMVKWDJKXLZM' > "$tmp" &&
md5sum < "$tmp"
rm -f -- "$tmp"

Regards,

Ed.

Helmut Waitzmann

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Oct 12, 2021, 2:23:56 PM10/12/21

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Ed Morton <morto...@gmail.com>:

>Right, it's saving a string into a temp file and than using that as
>the input to the command so, since every line in a POSIX text file
>must end in `\n`, `<<<` has to add one. It's equivalent to manually
>writing:
>
> tmp=$(mktemp) &&
> printf '%s\n' 'TASCJO3RJMVKWDJKXLZM' > "$tmp" &&
> md5sum < "$tmp"
> rm -f -- "$tmp"

On my debian linux machine it's more like

(
tmp="$(mktemp)" &&

printf '%s\n' 'TASCJO3RJMVKWDJKXLZM' > "$tmp" &&

exec 0< "$tmp" &&
rm -f -- "$tmp" &&
exec md5sum
)

hongy...@gmail.com

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Oct 12, 2021, 10:53:43 PM10/12/21

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On Tuesday, October 12, 2021 at 9:30:08 PM UTC+8, Christian Weisgerber wrote:
> On 2021-10-12, hongy...@gmail.com <hongy...@gmail.com> wrote:
> > But how to supply string for md5sum without '\n'?
> $ printf '%s' 'TASCJO3RJMVKWDJKXLZM' | md5

I don't have md5 command, but instead md5sum.

hongy...@gmail.com

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Oct 12, 2021, 11:06:10 PM10/12/21

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I'm on Ubuntu 20.04.2 LTS, both the above two methods work, but why do you prefer the latter?

HZ

hongy...@gmail.com

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Oct 12, 2021, 11:07:53 PM10/12/21

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Geoff Clare

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Oct 14, 2021, 8:41:05 AM10/14/21

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Only if you use a version of echo that does not conform to UNIX
requirements (even though it may conform to POSIX requirements).
POSIX allows -n to be special, but UNIX does not. A UNIX-conforming
echo does this:

$ echo -n foo
-n foo
$

The portable way to omit the newline is to use printf.

--
Geoff Clare <net...@gclare.org.uk>

hongy...@gmail.com

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Oct 15, 2021, 12:41:05 AM10/15/21

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Thank you for pointing this out.

HZ