Thread: scanf() works without parameters ?

I used a decompiler to decompile a C program and this is the result :

Code:

// address: 0x8048504
int main(int argc, char **argv, char **envp) {
    char local0[1024];         // m[r28 - 29]
    int local6;         // r24

    printf("What's the password? ");
    __isoc99_scanf();
    local6 = strcmp(local0, "gr8qw");
    if (local6 != 0) {
        local6 = puts("Sorry! Wrong password");
    } else {
        local6 = puts("Yes, you got the right password!");
    }
    return local6;
}

How does the scanf() even work in this piece of code ?

I recalled that scanf needs to have a format string like %d etc..

Thanks @grumpy for the detailed explanation.

I used the Boomerang Decompiler for this.