Select sorting in C

We are searching for the least item and insert it into head of array. But on its place - head, i.e. swaps head and this item. Then we are shift head by 1 and make the same. Very simple algorithm :)

#include <stdio.h>
#include "algutils.h"

template<typename T>
int selsort(T* arr, unsigned int len)
{
    T elmin;
    int i, off, imin;
    if (!arr||!len) return (0);

    for (off=0; off<len; off++) {
        for (i=off, elmin=arr[off], imin=-1; i<len; i++) {
            if (elmin > arr[i]) {
                elmin = arr[i];
                imin = i;
            }
        }
        if (imin != -1) {
            arr[imin] = arr[off];
            arr[off] = elmin;
        }
    }
    return (1);
}

/*****************************************
                    Main
 *****************************************/
int main(void)
{
    int arr[] = {2, 1, 0, 10, 9, 99, 8, -1, 6, 15, 15};
    PRINTARR(arr, "%d");
    selsort(arr, sizeofarray(arr));
    PRINTARR(arr, "%d");
    return (0);
}