When installing or setting up frameworks, in this case I was playing around with Laravel, you usually need to set a session/secret/encryption key.

I know why this is, but I always end up looking around for some random password generator so I can get a random string that is exactly 32 characters. Isn’t there an easier way?!?!

Yes there is. If you have the magical OpenSSL installed, which most do, you can use it to generate a random string.

I found a article online that uses base64 to generate a string of a certain length. The only thing is that base64 is padded with 8 bits. Which means that if you want 32 then you need to use 24. This goes up exponentially as the number gets bigger. So there is a trim part of the function that clips off the extra characters.

Here is the function broken down into steps:

  • pass a number to the function
  • cut the resulting string
  • generate a base64 string using that number
  • echo out the result
  • copy the output to the clipboard with a newline
  • echo out a success

I put a check in there if the argument is not a number. This is just for the dummies out there.

pbcopy is not defined

You are probably on Linux. I found this little snippet for the lazy. This way you can forget about translating it each time.

alias pbcopy="xsel --clipboard --input"
alias pbpaste="xsel --clipboard --output"

Now for the actual shell function:


# if the argument is a number
# cut the string so that there is no base64 padding
# generate a random password of the specified length
# then copy it to the clipboard without a newline
# usage: password 32
password() {
  if [[ $LENGTH =~ $REGEX ]] ; then
    PASSWD=$(openssl rand -base64 $LENGTH | head -c$LENGTH)
    echo $PASSWD
    echo $PASSWD | tr -d '\n' | pbcopy
    echo "Password copied to clipboard"
    echo "Argument must be a number"

Here is how you would use it, and what the results would look like:


~ ❯ password 32
Password copied to clipboard
~ ❯ password fu
Argument must be a number
~ ❯

This function would be put in your .bashrc file, or you .zshrc file if you are a cool ZSH user.