#include <stdlib.h>#include <stdio.h>#include <stdarg.h>#include <ctype.h>#include "mstring.h"/* parameters about string length.  START is the starting size and** START+TAIL should be a power of two */#define START	24#define TAIL	8void msprintf(struct mstring *s, const char *fmt, ...){static char	buf[4096];	/* a big static buffer */va_list		args;int		len;    if (!s || !s->base) return;    va_start(args, fmt);    vsprintf(buf, fmt, args);    va_end(args);    len = strlen(buf);    if (len > (s->end - s->ptr)) {	int	cp = s->ptr - s->base, cl = s->end - s->base, nl = cl;	while (len > (nl - cp))	    nl = nl + nl + TAIL;	if ((s->base = realloc(s->base, nl))) {	    s->ptr = s->base + cp;	    s->end = s->base + nl; }	else {	    s->ptr = s->end = 0;	    return; } }    memcpy(s->ptr, buf, len);    s->ptr += len;}int mputchar(struct mstring *s, int ch){    if (!s || !s->base) return ch;    if (s->ptr == s->end) {	int len = s->end - s->base;	if ((s->base = realloc(s->base, len+len+TAIL))) {	    s->ptr = s->base + len;	    s->end = s->base + len+len+TAIL; }	else {	    s->ptr = s->end = 0;	    return ch; } }    *s->ptr++ = ch;    return ch;}struct mstring *msnew(void) {    struct mstring *n = malloc(sizeof(struct mstring));    if (n && (n->base = n->ptr = malloc(START)))	n->end = n->base + START;    else if (n) {	free(n);	n = 0; }    return n;}char *msdone(struct mstring *s){char	*r = 0;    if (s) {	mputc(s, 0);	r = s->base;	free(s); }    return r;}/* compare two strings, ignoring whitespace, except between two letters or** digits (and treat all of these as equal) */int strnscmp(const char *a, const char *b){    while(1) {	while (isspace(*a)) a++;	while (isspace(*b)) b++;	while (*a && *a == *b) a++,b++;	if (isspace(*a)) {	    if (isalnum(a[-1]) && isalnum(*b))		break; }	else if (isspace(*b)) {	    if (isalnum(b[-1]) && isalnum(*a))		break; }	else	    break; }    return *a - *b;}unsigned int strnshash(const char *s){unsigned int	h = 0;    while (*s) {	if (!isspace(*s))	    h = (h<<5) - h + *s;	s++; }    return h;}