shell variable value not storing inside file

Question

I wrote following script, which generate random password and store it in file

pass1=</dev/urandom tr -dc _A-Z-a-z-0-9|head -c8
echo $pass1
echo "$pass1" >/tmp/a

Above script printing generated password through "echo $pass1" command. But nothing getting stored inside created /tmp/a file .

Please let me know whats wrong i am doing.

@jscott, this is a [unique usage of the `<` operator](http://unix.stackexchange.com/questions/40837/bash-linux-random-cli-password-generator-and) — Mike Pennington, Jun 22 '12 at 16:00
@MikePennington Thanks for that, I was trying to work through the syntax and what the expected output is... Both the OP's and your examples produce `tr` errors for me. — jscott, Jun 22 '12 at 16:03

score 1 · Accepted Answer · answered Jun 22 '12 at 15:58

1

It's not necessary to store the password in an intermediate variable. You only need this line in your shell script

</dev/urandom tr -dc _A-Z-a-z-0-9|head -c8 > /tmp/a

I saved as foo.sh, made permissions 755, and executed it under linux...

[mpenning@chestnut ~]$ uname -a
Linux chestnut.he.net 2.6.32.46-1-grsec #1 SMP Fri Sep 2 12:42:23 PDT 2011 x86_64 GNU/Linux
[mpenning@chestnut ~]$ ./foo.sh
[mpenning@chestnut ~]$ cat /tmp/a
qAUezN0-[mpenning@chestnut ~]$

answered Jun 22 '12 at 15:58

Mike Pennington

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This gives me: `tr: write error: Broken pipe` `tr: write error` – jscott Jun 22 '12 at 16:00
hmm works in cygwin and linux... see my edit – Mike Pennington Jun 22 '12 at 16:01
Thanks , this worked for me /tmp/a – vnix27 Jun 22 '12 at 16:09
Oh my, I'm still getting the `tr` errors, yet `/tmp/a` is created and contains the expected data. Odd, must be something screwy in my shell. +1 – jscott Jun 22 '12 at 16:11
@vnix27, FYI... there is also the `mkpasswd` command on most linux systems, but I like the control `tr` gives me – Mike Pennington Jun 22 '12 at 16:18

shell variable value not storing inside file

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