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#include <stdio.h>#include <stdlib.h>#include <unistd.h>#include <fcntl.h>#include <sys/mman.h>#include <sys/stat.h>int main(int argc, char **argv){	struct stat stbuf;	char *anon, *foo;	int fd, i;	fd = open(argv[1], O_RDWR);	if (fd == -1)		return 1;	if (fstat(fd, &stbuf) == -1)		return 1;	anon = mmap(NULL, 10 * 4096, PROT_READ | PROT_WRITE,		    MAP_SHARED | MAP_ANONYMOUS, -1, 0);	if (anon == MAP_FAILED)		return 1;	foo = mmap(anon + 4096, 4096, PROT_READ | PROT_WRITE,		   MAP_FIXED | MAP_SHARED, fd, 0);	if (foo == MAP_FAILED) {		printf("could not map\n");		return 1;	}	for (i = 0; i < 10; i++)		printf("first byte of page[%d] = 0x%02x\n", i, anon[i * 4096]);	munmap(foo, 4096);	for (i = 0; i < 10; i++)		printf("first byte of page[%d] = 0x%02x\n", i, anon[i * 4096]);	munmap(anon, 10 * 4096);	close(fd);	return 0;}