#include <stdlib.h>#include <unistd.h>#include <assert.h> void_assert(char *f, unsigned line){	char buf[20], *p, *s = &buf[20];	write(2, "assertion failed: file ", 23);	for(p = f; *p; p++) continue;	write(2, f, p-f);	write(2, ":", 7);	*--s = '\n';	do *--s = line%10 + '0'; while (line /= 10);	write(2, s, &buf[20] - s);	abort();	}