What are some obscure C statements?

[Syscal]

Has anyone got any extremely obscure yet very useful C statements?

This one isn't so obscure but I have not seen it in any text book I've read:

int x = 2;

printf("%i\n",!!x) // x != 0

This one I had never seen either:

int array[5];
int (*ptr_to_array)[5] = &array

(*ptr_to_array)[0] = 5;

printf("%i\n",(*ptr_to_arry)[0]);

Is the second one ever even useful?

[Adak]

Not in my opinion! PITA!

The obscure C stuff for me, is the low level io - using file handles instead of file streams, etc. How useful I'm not sure.

[Bayint Naung]

IOCC

[CommonTater]

x = (x > 10) ? x : 10;

[Adak]

x = (x > 10) ? x : 10;

Oh Yeah! Good one!!

[Sebastiani]

IOCC

Unrelated, but nonetheless relevant:

OIOIC

Read the code and you'll understand.

[adeyblue]

OIOIC

You know, everytime I see his/her name I can't help but read it as Perverse Zhao. I'm still not sure if that's a subconscious comment on the project or my uncouth mind.

[CommonTater]

Oh Yeah! Good one!!

Yeah... and the really sad thing is I use it quite often.

Such as ....

x = ((x % 30) > 14) ? x + 15 : x - 15;

Which I actually used not too long ago...

[Char*Pntr]

#include "stdio.h"
#define e 3
#define g (e/e)
#define h ((g+e)/2)
#define f (e-g-h)
#define j (e*e-g)
#define k (j-h)
#define l(x) tab2[x]/h
#define m(n,a) ((n&(a))==(a))

long tab1[]={ 989L,5L,26L,0L,88319L,123L,0L,9367L };
int tab2[]={ 4,6,10,14,22,26,34,38,46,58,62,74,82,86 };

main(m1,s) char *s; {
    int a,b,c,d,o[k],n=(int)s;
    if(m1==1){ char b[2*j+f-g]; main(l(h+e)+h+e,b); printf(b); }
    else switch(m1-=h){
        case f:
            a=(b=(c=(d=g)<<g)<<g)<<g;
            return(m(n,a|c)|m(n,b)|m(n,a|d)|m(n,c|d));
        case h:
            for(a=f;a<j;++a)if(tab1[a]&&!(tab1[a]%((long)l(n))))return(a);
        case g:
            if(n<h)return(g);
            if(n<j){n-=g;c='D';o[f]=h;o[g]=f;}
            else{c='\r'-'\b';n-=j-g;o[f]=o[g]=g;}
            if((b=n)>=e)for(b=g<<g;b<n;++b)o[b]=o[b-h]+o[b-g]+c;
            return(o[b-g]%n+k-h);
        default:
            if(m1-=e) main(m1-g+e+h,s+g); else *(s+g)=f;
            for(*s=a=f;a<e;) *s=(*s<<e)|main(h+a++,(char *)m1);
        }
}

I'm using MS VS 2010, ignore any warnings... it worked fine. The only thing useful was, it gave me a laugh after running it.

[Phenom]

#include "stdio.h"
#define e 3
#define g (e/e)
#define h ((g+e)/2)
#define f (e-g-h)
#define j (e*e-g)
#define k (j-h)
#define l(x) tab2[x]/h
#define m(n,a) ((n&(a))==(a))

long tab1[]={ 989L,5L,26L,0L,88319L,123L,0L,9367L };
int tab2[]={ 4,6,10,14,22,26,34,38,46,58,62,74,82,86 };

main(m1,s) char *s; {
    int a,b,c,d,o[k],n=(int)s;
    if(m1==1){ char b[2*j+f-g]; main(l(h+e)+h+e,b); printf(b); }
    else switch(m1-=h){
        case f:
            a=(b=(c=(d=g)<<g)<<g)<<g;
            return(m(n,a|c)|m(n,b)|m(n,a|d)|m(n,c|d));
        case h:
            for(a=f;a<j;++a)if(tab1[a]&&!(tab1[a]%((long)l(n))))return(a);
        case g:
            if(n<h)return(g);
            if(n<j){n-=g;c='D';o[f]=h;o[g]=f;}
            else{c='\r'-'\b';n-=j-g;o[f]=o[g]=g;}
            if((b=n)>=e)for(b=g<<g;b<n;++b)o[b]=o[b-h]+o[b-g]+c;
            return(o[b-g]%n+k-h);
        default:
            if(m1-=e) main(m1-g+e+h,s+g); else *(s+g)=f;
            for(*s=a=f;a<e;) *s=(*s<<e)|main(h+a++,(char *)m1);
        }
}

I'm using MS VS 2010, ignore any warnings... it worked fine. The only thing useful was, it gave me a laugh after running it.

Really cool!