Bash function to generate a random alphanumeric string

You can use this Bash function in your .bashrc file to generate a random alphanumeric string. This comes in handy when you need to generate a long, secure password for example. Adjust to your needs.

random-string() {
        cat /dev/urandom | tr -dc 'a-zA-Z0-9' | fold -w ${1:-32} | head -n 1
}

An example usage and output is

$ random-string
2fORqF7pau7bLafFuJbQNzK2D8yOLMnO

If needed you can add special characters to the tr command:

tr -dc '(\&\_a-zA-Z0-9\^\*\@'

This’ll generate a more secure random string, like:

$ random-string
w4LD528^K52@rrYx@vfEg1wKwRSMQXoP
$ random-string
BnhUn_ScM&sIs(Yn0d40PxJKUQN0QkHg
$ random-string
cFg3FRPHB6SXcQ(f8wGr7y1RKSR1i^&i

This is kindly taken from ghost’s comment in earthgecko’s gist bash.generate.random.alphanumeric.string.sh.

Jan Reilink

My name is Jan. I am not a hacker, coder, developer, programmer or guru. I am merely a system administrator, doing my daily thing at Vevida in the Netherlands. With over 15 years of experience, my specialties include Windows Server, IIS, Linux (CentOS, Debian), security, PHP, WordPress, websites & optimization.
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