未知类型名称'caddr_t'错误

Question

我正在尝试使用

设置“共享”内存位置

caddr_t mmap_ptr;

但是我收到了错误。有帮助吗？谢谢！

另外

mmap_ptr = mmap((caddr_t) 0,   /* Memory Location, 0 lets O/S choose */
    MAX_BUFFER_SIZE,/* How many bytes to mmap */
    PROT_READ | PROT_WRITE, /* Read and write permissions */
    MAP_SHARED,    /* Accessible by another process */
    fid,           /* which file is associated with mmap */
    (off_t) 0);    /* Offset in page frame */

Answer 1

caddr_t是一个BSD主义，而且是旧的。在Linux（和POSIX）下，mmap返回一个void指针。

#include <sys/mman.h>
void *mmap (void *addr,
            size_t length,
            int prot,
            int flags,
            int fd,
            off_t offset);
int munmap (void *addr,
            size_t length);