write - write to a file descriptor
ssize_t write(int fd, const void *buf, size_t count
write writes up to count bytes to the file referenced by the
file descriptor fd from the buffer starting at buf. POSIX
requires that a read() which can be proved to occur after a
write() has returned returns the new data. Note that not
all file systems are POSIX conforming.
On success, the number of bytes written are returned (zero
indicates nothing was written). On error, -1 is returned,
and errno is set appropriately. If count is zero and the
file descriptor refers to a regular file, 0 will be returned
without causing any other effect. For a special file, the
results are not portable.
fd is not a valid file descriptor or is not open for
fd is attached to an object which is unsuitable for
buf is outside your accessible address space.
fd is connected to a pipe or socket whose reading end
is closed. When this happens the writing process will
receive a SIGPIPE signal; if it catches, blocks or
ignores this the error EPIPE is returned.
Non-blocking I/O has been selected using O_NONBLOCK and
there was no room in the pipe or socket connected to fd
to write the data immediately.
The call was interrupted by a signal before any data
The device containing the file referred to by fd has no
room for the data.
EIO A low-level I/O error occurred while modifying the
Other errors may occur, depending on the object connected to
SVr4, SVID, POSIX, X/OPEN, 4.3BSD. SVr4 documents addi-
tional error conditions EDEADLK, EFBIG, ENOLCK, ENOLNK,
ENOSR, ENXIO, EPIPE, or ERANGE. Under SVr4 a write may be
interrupted and return EINTR at any point, not just before
any data is written.
open(2), read(2), fcntl(2), close(2), lseek(2), select(2),
ioctl(2), fsync(2), fwrite(3).