Differences between current version and predecessor to the previous major change of readv(2).
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| Newer page: | version 2 | Last edited on Sunday, March 16, 2003 9:23:00 pm | by PerryLorier | |
| Older page: | version 1 | Last edited on Tuesday, June 4, 2002 12:23:44 am | by perry | Revert |
@@ -1,135 +1,43 @@
-READV
-!!!READV
-NAME
-SYNOPSIS
-DESCRIPTION
-RETURN VALUE
-ERRORS
-CONFORMING TO
-SEE ALSO
-----
!!NAME
+readv, writev - read or write a vector
-
-readv, writev - read or write a vector
!!SYNOPSIS
+ __#include <sys/uio.h>__
+ __int readv(int__ ''fd''__, const struct iovec *__ ''vector''__, int__ ''count''__);__
-__#include
__
+
__int writev(int__ ''fd''__, const struct iovec *__ ''vector''__, int__ ''count''__);
__
+ __struct iovec {__
+ ptr_t__ ''iov_base''__;__ /* Starting address. */__
+ size_t__ ''iov_len''__;__ /* Length in bytes. */__
+ __};__
-__int readv(int__ ''fd''__, const struct iovec *__
-''vector''__, int__ ''count''__);__
-
-
-__int writev(int__ ''fd''__, const struct iovec *__
-''vector''__, int__ ''count''__);__
-
-
-__struct iovec {
-__ptr_t__ ''iov_base''__;__ /* Starting address.
-*/__
-size_t__ ''iov_len''__;__ /* Length in bytes.
-*/__
-};__
!!DESCRIPTION
+readv(2) reads data from file descriptor ''fd'', and puts the result in the buffers described by ''vector''. The number of buffers is specified by ''count''. The
+buffers are filled in the order specified. Operates just like __read__ except that data is put in ''vector'' instead of a contiguous buffer.
+__writev__ writes data to file descriptor ''fd'', and from the buffers described by ''vector''. The number of buffers is specified by ''count''. The buffers are used
+in the order specified. Operates just like __write__ except that data is taken from ''vector'' instead of a contiguous buffer.
-__readv__ reads data from file descriptor ''fd'', and
-puts the result in the buffers described by ''vector''.
-The number of buffers is specified by ''count''. The
-buffers are filled in the order specified. Operates just
-like __read__ except that data is put in ''vector''
-instead of a contiguous buffer.
-
-
-__writev__ writes data to file descriptor ''fd'', and
-from the buffers described by ''vector''. The number of
-buffers is specified by ''count''. The buffers are used
-in the order specified. Operates just like __write__
-except that data is taken from ''vector'' instead of a
-contiguous buffer.
!!RETURN VALUE
+On success __readv__ returns the number of bytes read. On success __writev__ returns the number of bytes written. On error, -1 is returned, and ''errno'' is set appropriately.
-
-On success __readv__ returns the number of bytes read. On
-success __writev__ returns the number of bytes written.
-On error, -1 is returned, and ''errno'' is set
-appropriately.
!!ERRORS
+;[EINVAL]: An invalid argument was given. For instance ''count'' might be greater than __MAX_IOVEC__, or zero. ''fd'' could also be attached to an object which is unsuitable for reading (for __readv__) or writing (for __writev__).
+;[EFAULT]: vector'' or some of the ''iov_base'' pointers points to memory that is not properly allocated.
+;[EBADF]: The file descriptor ''fd'' is not valid.
+;[EINTR]: The call was interrupted by a signal before any data was read/written.
+;[EAGAIN]: Non-blocking I/O has been selected using __O_NONBLOCK__ and no data was immediately available for reading. (Or the file descriptor ''fd'' is for an object that is locked.)
+;[EISDIR]: ''fd'' refers to a directory.
+;[EOPNOTSUP]: ''fd'' refers to a socket or device that does not support reading/writing.
+;[ENOMEM]: Insufficient kernel memory was available.
+Other errors may occur, depending on the object connected to ''fd''.
-__EINVAL__
-
-
-An invalid argument was given. For instance ''count''
-might be greater than __MAX_IOVEC__, or zero. ''fd''
-could also be attached to an object which is unsuitable for
-reading (for __readv__) or writing (for
-__writev__).
-
-
-__EFAULT__
-
-
-vector'' or
-some of the ''iov_base'' pointers points to memory that
-is not properly allocated.
-
-
-__EBADF__
-
-
-The file descriptor ''fd'' is not valid.
-
-
-__EINTR__
-
-
-The call was interrupted by a signal before any data was
-read/written.
-
-
-__EAGAIN__
-
-
-Non-blocking I/O has been selected using __O_NONBLOCK__
-and no data was immediately available for reading. (Or the
-file descriptor ''fd'' is for an object that is
-locked.)
-
-
-__EISDIR__
-
-
-''fd'' refers to a directory.
-
-
-__EOPNOTSUP__
-
-
-''fd'' refers to a socket or device that does not support
-reading/writing.
-
-
-__ENOMEM__
-
-
-Insufficient kernel memory was available.
-
-
-Other errors may occur, depending on the object connected to
-''fd''.
!!CONFORMING TO
+4.4BSD (the __readv__ and __writev__ functions first appeared in BSD 4.2), Unix98. Linux libc5 uses __size_t__ as the type of the ''count'' parameter, which is logical
+but non-standard.
-
-4.4BSD (the __readv__ and __writev__ functions first
-appeared in BSD 4.2), Unix98. Linux libc5 uses __size_t__
-as the type of the ''count'' parameter, which is logical
-but non-standard.
!!SEE ALSO
-
-
-
-
-----
+read(2), write(2), fprintf(3), fscanf(3)
