Performs a read on an open file with arguments passed.
Item | Description |
---|---|
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 is located:
|
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.
Item | Description |
---|---|
0 | Indicates successful completion. |
If an error occurs, one of the values from the /usr/include/sys/errno.h file is returned.