Reverse a stack (inplace)

inplacerevstack.c

/***
This program is similar to reversing a linked list. I have done anyway for the heck of it!
****/

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

typedef struct _node {
    int value;
    struct _node * next;
} node;

typedef node stack;

void printS(stack * L){

    node * temp = L;

    printf("Stack : ");
    while(temp != NULL){
        printf("%d ", temp->value);
        temp = temp->next;
    }
    printf("\n");
}

stack * Push(int X, stack * S){

    node * temp;
    temp = malloc(sizeof(node));
    temp->value = X;

    if(S==NULL){
        return temp;
    }
    else{

        temp->next = S;
        return temp;
    }

}

int Pop(stack **S){

    int i;

    i = (*S)->value;
    *S = (*S)->next;
    return i;

}

stack * RevStack(stack *S){

    node *previous, *present, *next;

    previous = NULL;
    present  = S;
    next = S->next;

    while(present!=NULL){

        present->next = previous;
        previous = present;
        present = next;
        if(next!=NULL)
        next = next->next;
    }

    printf("Reversed...\n");
    printS(previous);
    return previous;

}

int main(){

    stack * S = NULL;
    int i,X;

    while(1){

    printf("What do you want to do? 1. Push, 2. Pop 3. Exit 4. Print 5.Reverse\n");
    scanf("%d", &i);

    switch(i){

        case 1:
        printf("Enter number:\n");
        scanf("%d",&X);
        S = Push(X,S);
        break;

        case 2:
        X = Pop(&S);
        printf("Popped %d\n",X);
        break;

        case 4:
            printS(S);
        break;

        case 5:
            RevStack(S);
        break;

        case 3:
            exit(1);
        default :
        printf("Wrong choice\n");

    }

    }

}