Re: [Cppcms-users] how to use cppcms::urandom_device to generate a random string and output it as a string

[Marcel H. <ke...@co...>]

Am 23.05.2012 13:03, schrieb Zheng Ping:
> Hi, all:
>    I am a green hand to cppcms. I want to generate a random string by 
> using cppcms::urandom_device. my codes are:
>    char buf[32];
>    cppcms::urandom_device random_device;
>    random_device.generate(buf, 16);
>    std::string output(buf);
>    std::cout << output << std::endl;
>    .... ...
>    The above codes will output garbled codes, I don't know how to get 
> readable random string by using cppcms::urandom_device, who can give 
> me an advise?
>
> -- 
> with kind regards
>
>
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what does a random device does? It "prints" out chars in range from 0 to 
1 << CHAR_BIT -1
What is "printable"?
http://www.asciitable.com/
nums in range from 33 - 126 and some extended ascii codes. A char is 
nothing different than unsigned int with the length of CHAR_BIT 
("normally" 8).

What you can do is, define an array with all the letters you want to 
print and then create a random number in range from 0 to array.length() 
and then print it out via direct array access.

Hope it helpes a bit.

Regards