### Intuitive compare function in AceDB utils.c.

### lextstrcmp()

Although lexstrcmp has been available in AceDB since the early 1990's its full functionality is not widely known, so it seems worth documenting it and a recent enhancement. It provides a means of sorting strings of mixed alpha and numeric characters into a more intuitive order than is possible using the standard alphabetic sort routines more normally associated with computers.

The intention is to sort strings like A11B and A100B into the order which I regard as intuitive, ie A11B precedes A100B, rather than the default alphabetic processing which would place A100B before A11B.

The routine is used by passing it char * pointers to the two strings to be compared.

    Prototype:
        int lexstrcmp(char *a,char *b);
    Examples:
        if (lexstrcmp(cp, name(tag)))
        return lexstrcmp(cp,cq) <= 0  ? TRUE : FALSE ;
        cmpClass = lexstrcmp(Text(objA), Text(objB));

In addition to this, a new function, arrstrcmp() has been provided recently. This is simply a wrapper routine which allows lexstrcmp to be utilised when sorting arrays, something not previously possible. It takes the void pointers that qsort requires it to have as parameters, casts them to char ** and dereferences them, since what is being sorted is an array of pointers to character strings.

To use the new routine when sorting an AceDB array called myArray, specify it as follows: arraySort(myArray, arrstrcmp);