Linux / Unix: Generate A MD5 String

Author: Vivek Gite Last updated: October 4, 2013 11 comments

I need to generate a md5 hash for given string. It will be used by shell script to generate keys for remote web service or cryptographic application. How do I generate a md5 hash based on any input string under Linux or Unix like operating systems?

Tutorial details
Difficulty	Easy (rss)
Root privileges	No
Requirements	None
Time	5m

You can use md5sum command to compute and check MD5 message digest. This is a default tool on most modern Linux distributions. It generate a md5 hash for given string or words or filenames.

Create a md5 string using md5sum command

Use the following syntax:

echo -n "Your-String-Here" | md5sum

In this example create a md5 hash for wpblog string that can be used by memcached server

 echo -n "wpblog" | md5sum

Sample outputs:

6afedb7a8348eb4ebdbe0c77ef92db4c -

You can store the same in a bash shell variable called hash as follows:

md5="set-string-here"
hash="$(echo -n "$md5" | md5sum )"
echo "$hash"

Recommended readings

See md5sum man page for more information.

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11 comments… add one

anton bors Jun 6, 2012 @ 8:07
Reading from standard input:
$ md5sum –
a little script:
#!/bin/bash
echo $1
echo $1 | md5sum
$ ./md5 hallo
hallo
aee97cb3ad288ef0add6c6b5b5fae48a –
The “-” declares, that this message comes from standard input
greets
Reply Link
- AtesComp Feb 21, 2014 @ 1:45
  Beware this script! You should use the “-n” option for echo as shown in the main article. Otherwise, a newline is appended to the output of the echo command and your hash will not be as advertised (unless you really want the newline).
  #!/bin/bash
  echo $1
  echo -n $1 | md5sum
  $ ./md5 hallo
  hallo
  598d4c200461b81522a3328565c25f7c –
  Not “aee97cb3ad288ef0add6c6b5b5fae48a” as shown above.
  Reply Link
  - Dorell James Galang Feb 17, 2016 @ 4:03
    If your hash contains a “–” at the end. Well, seriously this is not correct. I suggest you use this command instead to get rid of that character.
    echo -n "samplestring" | md5sum | cut -d"-" -f1 -
    Reply Link
Roy Bellingan Jun 12, 2012 @ 9:32
Remember that md5 should only used for file hash now, in recent days linked_in had a major password leakage for using md5…
md5 and password leaked.
Reply Link
- Drew H Dec 13, 2012 @ 3:21
  You’re an idiot mate
  Reply Link
  - Roy Bellingan Dec 13, 2012 @ 9:15
    Thanks, i’ll write this on my tombstone!
    Reply Link
Guy Merritt Aug 23, 2013 @ 17:50
I love this site – it’s got more simple, helpful tips for *Nix amateurs (like me!) than I’ve ever seen elsewhere. But, for the life of me, I can’t find a site search anywhere. I was looking for this page, because I’d forgotten the syntax to generate an encrypted password. What’s up with no site search…? If I wanted to search Google, I’d search Google. Anyway, thanks for all of the help. Great site.
Reply Link
Nick Gar Jul 12, 2016 @ 3:24
Unfortunately, this command creates completely wrong MD5 hashes under certain circumstances, for example if the string to be hashed contains both uppercase and lowercase letters or symbols.
Let’s take the string “8FdBd35E” as an example. Its correct MD5 hash is
2a6b2d4c5fbd87fd896177a8fd12d4d1
and PHP indeed creates the correct MD5 hash:
root@corp6 [~]# php -r “echo md5(‘8FdBd35E’);” | xargs echo
2a6b2d4c5fbd87fd896177a8fd12d4d1
However, the “md5sum” shell command creates a completely different MD5 hash:
root@corp6 [~]# echo “8FdBd35E” | md5sum
bf84cb9630c7748d0f337c98c2644051 –
Also, checked it with thousands other strings and md5sum creates an incorrect MD5 hash, so the command is not to be trusted.
Reply Link
- Thibault Jun 2, 2017 @ 6:54
  again, the add -n to remove the newline
  echo -n "8FdBd35E" | md5sum => 2a6b2d4c => 2a6b2d4c5fbd87fd896177a8fd12d4d1 php -r "echo md5('8FdBd35E');" | xargs echo => 2a6b2d4c5fbd87fd896177a8fd12d4d1
  Reply Link
Erich Oct 21, 2016 @ 10:03
That’s because ‘echo’ appends a newline. I tried your command with the ‘-n’ option and it worked as expected.
Reply Link
Pedro Dec 19, 2016 @ 23:28
username=user
password=passwd
hash_user="$(echo -n "$username" | md5sum )" hash_pass="$(echo -n "$password" | md5sum )"
as� me funciono gracias a tu post.
hash_username=$(echo $hash_user | sed 's/ //g' | sed 's/-//g') hash_username=$(echo $hash_pass | sed 's/ //g' | sed 's/-//g')
Reply Link