Linux How to Generate Random Password

Generating password is relatively simple and can be done in different ways. You can install tools to generate passwords, a few examples:

When you don’t have installed these tools, here are useful commands:

date +%s | sha256sum | base64 | head -c 32 ; echo

We used time in seconds as a input to hash function sha-256 and print first 32 chars. You can replate sha256sum with other hash function (md5sum).

strings /dev/urandom | grep -o '[[:alnum:]]' | head -n 32 | tr -d '\n'; echo

/dev/urandom is the built-in feature which generate random chars.

< /dev/urandom tr -dc _A-Z-a-z-0-9 | head -c32; echo

Another way using /dev/urandom, even simpler.

You can also create the script:

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

generatePasswd "$1"