*nix Documentation Project
·  Home
 +   man pages
·  Linux HOWTOs
·  FreeBSD Tips
·  *niX Forums

  man pages->Linux man pages -> write (2)              



NAME    [Toc]    [Back]

       write - write to a file descriptor

SYNOPSIS    [Toc]    [Back]

       #include <unistd.h>

       ssize_t write(int fd, const void *buf, size_t count);

DESCRIPTION    [Toc]    [Back]

       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.

RETURN VALUE    [Toc]    [Back]

       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.

ERRORS    [Toc]    [Back]

       EBADF  fd is not a valid file descriptor or is not open for writing.

       EINVAL fd is attached to an object which is unsuitable for writing.

       EFAULT buf is outside your accessible address space.

       EFBIG  An attempt was made to write a file that exceeds the implementation-defined
 maximum file size or the process' file size	limit,
	      or  to write at a position past than the maximum allowed offset.

       EPIPE  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

       EAGAIN Non-blocking  I/O  has  been  selected  using O_NONBLOCK and the
	      write would block.

       EINTR  The call was interrupted by a signal before any data  was  written.

       ENOSPC 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 inode.

       Other errors may occur, depending on the object connected to fd.

CONFORMING TO    [Toc]    [Back]

       SVr4, SVID, POSIX, X/OPEN, 4.3BSD.   SVr4  documents  additional  error
       Under SVr4 a write may be interrupted and return EINTR  at  any	point,
       not just before any data is written.

SEE ALSO    [Toc]    [Back]

       open(2),  read(2),  fcntl(2),  close(2), lseek(2), select(2), ioctl(2),
       fsync(2), fwrite(3)

Linux 2.0.32			  1996-01-13			      WRITE(2)
[ Back ]
 Similar pages
Name OS Title
pread Linux read from or write to a file descriptor at a given offset
pxfisatty IRIX Determines if file descriptor corresponds to a valid file descriptor
AFreadmisc IRIX read from / write to / move logical read/write pointer for data in a miscellaneous chunk in an audio file
fattach Tru64 Attach a STREAMS-based file descriptor to a file in the file system name space
fdetach Tru64 Detach a STREAMS-based file descriptor from a file in the file system name space
AFclosefile IRIX close an audio file, update file header if file was opened for write access.
sat_write_filehdr IRIX write audit file header, write close time to audit file header
AFopenfile IRIX allocate an AFfilehandle structure for an audio file identified by name / by a Unix file descriptor
AFidentifyfd IRIX retrieve the audio file format of a file descriptor / open AFfilehandle
fdetach Tru64 Detaches a STREAMS-based file descriptor from a file
Copyright © 2004-2005 DeniX Solutions SRL
newsletter delivery service