Random String in linux by system time

Question

I work with Bash. I want to generate randrom string by system time . The length of the unique string must be between 10 and 30 characters.Can anybody help me?

Accepted Answer

There are many ways to do this, my favorite one using the `urandom` device:

```
burhan@sandbox:~$ tr -cd '[:alnum:]' < /dev/urandom | fold -w30 | head -n1
CCI4zgDQ0SoBfAp9k0XeuISJo9uJMt
```

- `tr` (translate) makes sure that only alphanumerics are shown

- `fold` will wrap it to 30 character width

- `head` makes sure we get only the first line

To use the current system time (as you have this specific requirement):

```
burhan@sandbox:~$ date +%s | sha256sum | base64 | head -c30; echo
NDc0NGQxZDQ4MWNiNzBjY2EyNGFlOW
```

- `date +%s` = this is our date based seed

- We run it through a few hashes to get a "random" string

- Finally we truncate it to 30 characters

Other ways (including the two I listed above) are available at this page and others if you simply google.

Random String in linux by system time

Solution

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