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BASH/SH Random String/Password Generator

BASH/SH Random String/Password Generator

Wednesday 14 April, 2010

Blog

Need to generate a random a-zA-Z0-9 string in bash or sh? Well this little function should help.

You can passover the string length or leave it blank for an 8 character string.

Code

function randompass () {
        local randompassLength
        if [ $1 ]; then
                randompassLength=$1
        else
                randompassLength=8
        fi

        pass=</dev/urandom tr -dc A-Za-z0-9 | head -c $randompassLength
        echo $pass
}

Example Usage

#!/bin/bash
#

function randompass () {
        local randompassLength
        if [ $1 ]; then
                randompassLength=$1
        else
                randompassLength=8
        fi

        pass=</dev/urandom tr -dc A-Za-z0-9 | head -c $randompassLength
        echo $pass
}

fourChrString=`randompass 4`
eightChrString=`randompass`

echo "4 character random string : $fourChrString"
echo "8 character random string : $eightChrString"

Example Output

4 character random string : pnoc
8 character random string : c110EM21