[Bugsy]

You can modify the chars used by editing the ranges in CharRanges[] and code length by changing SecurityCodeLength value. It is currently setup to build a 6-character long code using characters 0-9, a-z, A-Z.

Sample output:

* Your security code is: xL8pqk
* Your security code is: r7CC44
* Your security code is: H3npmW
* Your security code is: XxJnJB
* Your security code is: O44oIA
* Your security code is: 8V08bw

PHP Code:

#include <amxmodx>

#define MAX_PLAYERS 32

const SecurityCodeLength = 6;

new const CharRanges[ 3 ][ 2 ] = 
{
    { '0' , '9' },  //0-9 = asc 48-57
    { 'A' , 'Z' },  //A-Z = asc 65-90
    { 'a' , 'z' }   //a-z = asc 97-122
};
    
new g_szSecurityCodes[ MAX_PLAYERS + 1 ][ SecurityCodeLength + 1 ];
 
public plugin_init()
{
    register_plugin( "Security Code" , "0.1" , "bugsy" );
    
    register_clcmd( "say /random" , "GenerateCode" );
}

public GenerateCode( id )
{
    new iCurSet;
    
    for ( new i = 0 ; i < SecurityCodeLength ; i++ )
    {
        iCurSet = random( sizeof( CharRanges ) );
        
        g_szSecurityCodes[ id ][ i ] = random_num( CharRanges[ iCurSet ][ 0 ] , CharRanges[ iCurSet ][ 1 ] );
    }
    g_szSecurityCodes[ id ][ SecurityCodeLength ] = EOS;

    client_print( id , print_chat , "* Your security code is: %s" , g_szSecurityCodes[ id ] );
}