Thread: Command To Generate Random Password String

Hello Nicraft users. I stumbled across this cool command today and I thought I would share it with you all. I have the task as a systems administrator to generate safe passwords for ftp accounts, user accounts etc... Sometimes this can be tedious business. Well I have a cool command tested in BASH and on RHEL that will do this for you


Check it out!!!!!!

Code:

[root@uranium ~]# < /dev/urandom tr -dc A-Za-z0-9_ | head -c8
jO_00rTf

You can change how many characters you want your password by the value -c*

Now don't waste to much of your day pressing enter over and over checking how random these strings are. I spent a solid hour today. HEHE

Jaysunn

I've added the following to my ~/.bashrc:

PHP Code:

genpasswd() { 
    local l=$1
           [ "$l" == "" ] && l=16
          tr -dc A-Za-z0-9_ < /dev/urandom | head -c ${l} | xargs 
} 


I added that as well to my ~.bashrc, to test what you have done. When I login, I get the same prompt. What should occur? From the code it looks like the obvious of a random string of some sort.

Can you please elaborate on that?

Thanks,

Jaysunn

I SEEEEEEE,

I just added a command called genpasswd. SWEET.

Jaysunn

File is ~/.bashrc and NOT ~.bashrc

Just type genpasswd to display password, it accepts a password length on fly:

Code:

genpasswd
genpasswd 10
genpasswd 24

SxdWVJW5pijD655_hEiOYHJ5

may i ask, where did you find command in first place? i'm sure it is not from the man page..lol

ps: this should in tutorial or shell forum

I found this on a pretty neat site:

[shell-fu:home]$

However you are correct about this going into a different forum. I did not expect to get a much great tip from Nixcraft. However I always manage to get great info here.

Jaysunn

Originally Posted by jaysunn

I found this on a pretty neat site:

[shell-fu:home]$

Great site and thread moved to shell scripting forum.

but facing issue with out put as below
[root@test ~]# getpasswd
1kMg9EF9[root@test ~]#

cant we get like this?

[root@test ~]# getpasswd
1kMg9EF9
[root@test ~]#

???????

Yes if you enter the command that I first posted just as is in BASH in RHEL. You get this:

Code:

[root@radio5 ~]# < /dev/urandom tr -dc A-Za-z0-9_ | head -c8
lQIvHjtj[root@radio5 ~]#

If you take this example one step further and edit your ~/.bashrc file and add the code that Nixcraft posted you can get a cleaner output.

Code:

[root@radio5 bin]# vi ~/.bashrc

Add this to the top of the file:

PHP Code:

genpasswd() { 
    local l=$1
           [ "$l" == "" ] && l=16
          tr -dc A-Za-z0-9_ < /dev/urandom | head -c ${l} | xargs 
} 


Next you type the following to generate a random password string:

Code:

[root@radio5 ~]# genpasswd 10
nCfKSfRxgU
[root@radio5 ~]#

You can alter the number 10 to whatever to get different values.

HTH,

Jaysunn

Originally Posted by jaysunn

Hello Nicraft users. I stumbled across this cool command today and I thought I would share it with you all. I have the task as a systems administrator to generate safe passwords for ftp accounts, user accounts etc... Sometimes this can be tedious business. Well I have a cool command tested in BASH and on RHEL that will do this for you


Check it out!!!!!!

Code:

[root@uranium ~]# < /dev/urandom tr -dc A-Za-z0-9_ | head -c8
jO_00rTf

You can change how many characters you want your password by the value -c*

Now don't waste to much of your day pressing enter over and over checking how random these strings are. I spent a solid hour today. HEHE

Jaysunn

Good code.

This inspired me to come up with my version which includes the special characters in the password. I use this kind of script to generate passwords for the new users (to make their life hell with these passwords)

Here it is:

PHP Code:

head -c 500 /dev/urandom | tr -dc 'a-zA-Z0-9~!@#$%^&*-_' | fold -w 8 | head -n 1 


You can change the count 8 in fold -w 8 to make the password string shorter or longer depending on your needs. Also, if you want multiple passwords at one go, you cant change the number in head -n 1 to something else