Open System Services System Calls Reference Manual (G06.25+, H06.03+)

System Functions (r) read(2)
• The processor for the disk process of the specified file failed during an
input or output operation, and takeover by the backup process occurred.
• The open file descriptor has migrated to a new processor, but the new
processor lacks a resource or system process needed for using the file
descriptor.
The file descriptor specified by the filedes parameter can only be closed.
For all other error conditions, errno is set to the appropriate Guardian file-system error number.
See the Guardian Procedure Errors and Messages Manual for more information about a specific
Guardian file-system error.
RELATED INFORMATION
Functions: creat(2), dup(2), fcntl(2), ioctl(2), lseek(2), open(2), opendir(3), pipe(2), socket(2).
STANDARDS CONFORMANCE
The HP implementation does not return the
errno value [EWOULDBLOCK] for a call on a
socket that has O_NONBLOCK set when no data is available.
The POSIX standards leave some features to the implementing vendor to define. These features
are affected in the HP implementation:
• The value of the file pointer returned for a device that is incapable of seeking is always 0
(zero).
• When reading from a device special file, the return of EOF has no effect on subsequent
calls to the read() function.
• Specifying a value for the nbytes parameter that is greater than SSIZE_MAX causes the
read() function to return -1 and set errno to [EINVAL].
• errno can be set to [EIO] if a physical I/O error occurs.
HP extensions to the XPG4 Version 2 specification are:
• The errno values [ECONNRESET], [EFAULT], [EFILEBAD], [EINVAL], [EISDIR],
[EISGUARDIAN], [ENETDOWN], [ENOTCONN], [ETIMEDOUT], and [EWRON-
GID] can be returned.
527186-003 Hewlett-Packard Company 6−5