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#include <sys/types.h>
#include <sys/fcntl.h>
#include <sys/mman.h>
#include <unistd.h>
int main(int argc, char** argv)
{
int fd, fd2;
caddr_t addr;
char zeros[4096];
char ones[200];
memset(zeros, 0, sizeof zeros);
memset(ones, 1, sizeof ones);
#if 0
unlink("test1.data");
fd = open("test1.data", O_RDWR|O_CREAT, 0666);
if (fd < 0)
err(1, "creating file");
if (write(fd, zeros, sizeof zeros) < 0)
err(1, "writing zeros");
close(fd);
#endif
fd = open("test1.data", O_RDWR);
if (fd < 0)
err(1, "opening file");
if (lseek(fd, 600, SEEK_SET) < 0)
err(1, "seeking");
if (write(fd, ones, sizeof ones) < 0)
err(1, "writing ones");
fsync(fd);
addr = mmap(0, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
if (addr == MAP_FAILED)
err(1, "mapping");
unlink("test1.scratch");
fd2 = open("test1.scratch", O_RDWR|O_CREAT, 0666);
if (fd2 < 0)
err(1, "creating scratch");
if (write(fd2, addr, 4096) < 0)
err(1, "writing scratch");
}
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