Performs a read operation on an open file with arguments passed in iovec elements.
#include <sys/types.h> #include <sys/errno.h>
int fp_readv
(fp, iov, iovcnt, ext,
segflag, countp)
struct file * fp;
char * iov;
int iovcnt;
int ext;
int segflag;
int * countp;
| fp | Points to a file structure returned by the fp_open kernel service. |
| iov | Points to an array of iovec elements. Each iovec element describes a buffer where data to be read from the file is to be stored. |
| iovcnt | Specifies the number of iovec elements in the array pointed to by the iov parameter. |
| ext | Specifies an extension argument required by some device drivers. Its content, form, and use are determined by the individual driver. |
| segflag | Indicates in which part of memory the array specified by the iov parameter is located: |
| countp | Points to the location where the count of bytes actually read from the file is to be returned. |
The fp_readv kernel service is an internal interface to the function provided by the readv subroutine.
The fp_readv kernel service can be called from the process environment only.
| 0 | Indicates a successful operation. |
If an error occurs, one of the values from the /usr/include/sys/errno.h file is returned.
The readv subroutine.
Logical File System Kernel Services in AIX 5L Version 5.2 Kernel Extensions and Device Support Programming Concepts.