Performs a read on an open file with arguments passed.
#include <sys/types.h> #include <sys/errno.h>
int fp_read (fp, buf, nbytes, ext, segflag, countp) struct file *fp; char *buf; int nbytes; int ext; int segflag; int *countp;
|fp||Points to a file structure returned by the fp_open or fp_opendev kernel service.|
|buf||Points to the buffer where data read from the file is to be stored.|
|nbytes||Specifies the number of bytes to be read from the file into the buffer.|
|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 buffer specified by the buf parameter
|countp||Points to the location where the count of bytes actually read from the file is to be returned.|
The fp_read kernel service is an internal interface to the function provided by the read subroutine.
The fp_read kernel service can be called from the process environment only.
|0||Indicates successful completion.|
If an error occurs, one of the values from the /usr/include/sys/errno.h file is returned.
The fp_read kernel service is part of Base Operating System (BOS) Runtime.
The read subroutine.
Logical File System Kernel Services in AIX Version 4.3 Kernel Extensions and Device Support Programming Concepts.