Thread: random password generator

Hi, I am new to C and I am trying to write a program that will take in regular easy to remember passwords like 'JohnDoe' and encrypt them with random characters. This is what I have so far:
//passGen.c

Code:

#include <stdlib.h>
#include <stdio.h>

int main(void) {
    int length = 8;
    int r,i;
    char c;
    srand((unsigned int)time(0)); //Seed number for rand()
    for(i=0;i<length; i++) {
        r = rand() + 33;
        c = (char)r;
        printf("%c",c);
    }
}

To run it in Linux/Unix do ./a.out or a.out passGen JohnDoe
The program works just the way I want it to, except I would like to narrow down the types of characters it uses. How would I modify it to only use 'normal' English letters (both upper and lower case,) numbers and only the additional characters ^, #, $ and @ for encryption? Also, I want to keep the integer length the same.