wyfifofile.3wy

一个不错

.PP
.BI "virtual WyRet reset(const char* " "pathname " ",int " "f" ")" 
.PP
.BI "virtual WyRet reset(const WyStr& " "pathname " ",int " "f" ")" 
.PP
    Reconstruct *this to the state as WyFifoFile(\fIpathname\fP,\fIf\fP)

      \fIf\fP= flags for ::open, except O_CREAT

    Note: Opening a FIFO may block, see fifo(4)
.PP
    [\fBRet\fP] Ok              Succeed. Error report from closing the 
                          previously associated device is ignored
          Wym_EINVAL      \fIf\fP invalid
          Wym_EBADF       File is not valid for the operation
          Wym_EACCES      Search permission is denied
          Wym_ENAMETOOLONG Pathname too long
          Wym_ENOENT      Pathname does not exist
          Wym_ENOTDIR     Entry in pathname is not a directory
          Wym_EMFILE      Too many open fd
          Wym_ENFILE      File table overflow
          Wym_ENOMEM      Not enough memory
          Wym_EEXIST      Pathname already exists
          Wym_EINTR       Interrupted by a signal
          Wym_ENOSPC      Device left no space for the operation
          Wym_ENXIO       No such device (device not ready)
          Wym_EROFS       Read-only file system
          Wym_ENODEV      No such device
          Wym_ELOOP       Too many symbolic links encountered
          ...             reply converted from the errno of ::open

    Note: Error report from closing the previously handled
          object is ignored. Use reset() first if the close
          return status is desired
.PP 
    [\fBRefer\fP] ::open(const char*,int)
.\"--------------------------------------------
.PP
.BI "virtual WyRet _swap(WySysFile& " "ff" ") throw()"
.PP
    Interchange state of *this with \fIff\fP
.PP
    [\fBRet\fP] Ok              Succeed
          Wym_EBADTYPE    \fIff\fP is not the same type
.\"--------------------------------------------
.PP
.BI "virtual WyFifoFile* _alloc(WyRet& " "r" ") const"
.PP
    Allocate a default object of the most inherited type that
    *this refers.

    Note: Inhertied class must override this member
          See man. wybyteflow(3wy) for the reimpement example.

    \fIr\fP is reset with the return status:
            Wym_ENOMEM      Not enough memory
            Wym_ENOSYS      *Not overridden
            ...             Same from constructing WyFifoFile()
.PP
    [\fBRet\fP] Pointer of the allocated object, or NULL if failed.
          User is responsible to \fBdelete\fP the returned object.
.\"--------------------------------------------
.PP
.BI "virtual WyRet read(void* " "buf" ", size_t " "count" ", size_t& " "n_read" ")"
.PP
    Read at most \fIcount\fP bytes of data into memory pointed by \fIbuf\fP.

    \fIn_read\fP is always written with the bytes read and stored
    into \fIbuf\fP.
.PP
    [\fBRet\fP] Ok              Succeed. Zero byte read means End-Of-file.
          Wym_EBADF       Object is not valid for the operation
          Wym_EFBIG       \fIcount\fP exceeds the maximum
          Wym_EINTR       Interrupted by a signal before any data read
          Wym_EAGAIN      Non-blocking I/O (no data read)
          Wym_EIO         Low level I/O error
          Wym_EINVAL      Device is not suitable for reading
          Wym_EFAULT      \fIbuf\fP is inaccessible
          Wym_ENOMEM      Not enough memory for \fIcount\fP
.PP 
    [\fBRefer\fP] ::read(int,void*,size_t)
.\"--------------------------------------------
.PP
.BI "virtual WyRet read(WyStr&" " buf" ", size_t " "count" ", size_t& " "n_read" ")"
.PP
    Read at most \fIcount\fP bytes of data and \fBappend\fP to \fIbuf\fP.

    \fIn_read\fP is always written with the bytes read and appended
    to \fIbuf\fP.
.PP
    [\fBRet\fP] Ok              Succeed. Zero byte read means End-Of-file.
          Wym_EBADF       Object is not valid for the operation
          Wym_EFBIG       \fIcount\fP exceeds the maximum
          Wym_EINTR       Interrupted by a signal before any data read
          Wym_EAGAIN      Non-blocking I/O (no data read)
          Wym_EIO         Low level I/O error
          Wym_EINVAL      Device is not suitable for reading
          Wym_ENOMEM      Not enough memory for \fIcount\fP
.PP 
    [\fBRefer\fP] ::read(int,void*,size_t)
.\"--------------------------------------------
.PP
.BI "virtual WyRet write(const void* " "buf" ", size_t " "count" ", size_t& " "n_written" ")"
.PP
    Write \fIcount\fP bytes of data in \fIbuf\fP to the system file.

    The number of written bytes is always stored into \fIn_written\fP
.PP
    Note: The writting of data is atomic if \fIcount\fP<=PIPE_BUF.
          If writting to a FIFO not opened for read on the other
          end, the process is send a SIGPIPE signal, see fifo(4).

    Note: The system buffer limits the bytes written. 
          Refer to system documents.
.PP
    [\fBRet\fP] Ok              Succeed
          Wym_EBADF       Object is not valid for the operation
          Wym_EFBIG       Attempt to write beyond the device limit 
          Wym_EINVAL      Object attatched device is not suitable
          Wym_EFAULT      \fIbuf\fP is inaccessible
          Wym_EPIPE       Write to a pipe or FIFO with no reader
          Wym_EAGAIN      Non-blocking I/O (write would block)
          Wym_EINTR       Interrupted by a signal before data written
          Wym_ENOSPC      Device left no space for the operation
          Wym_EIO         Low level I/O error
.PP 
    [\fBRefer\fP] ::write(int,const void*,size_t)
.\"--------------------------------------------
.PP
.BI "virtual WyRet write(WyCSeg " "buf" ", size_t& " "n_written" ")"
.PP
    Write data indicated by \fIbuf\fP to the system file

    The number of written bytes is always stored into \fIn_written\fP
.PP
    Note: The writting of data is atomic if \fIbuf\fP.size()<=PIPE_BUF.
          If writting to a FIFO not opened for read on the other
          end, the process is send a SIGPIPE signal, see fifo(4).
.PP
    [\fBRet\fP] Ok              Succeed
          Wym_EBADF       Object is not valid for the operation
          Wym_EINVAL      Object attatched device is not suitable
          Wym_EFBIG       Attempt to write beyond the device limit 
          Wym_EPIPE       Write to a pipe or FIFO with no reader
          Wym_EAGAIN      Non-blocking I/O (write would block)
          Wym_EINTR       Interrupted by a signal before data written
          Wym_ENOSPC      Device left no space for the operation
          Wym_EIO         Low level I/O error
.PP 
    [\fBRefer\fP] ::write(int,const void*,size_t)
.\"--------------------------------------------
.PP
.BI "virtual WyRet write(const WyStr& " "buf" ", size_t& " "n_written" ")"
.PP
    Write data in \fIbuf\fP to the device.

    The number of written bytes is always stored into \fIn_written\fP
.PP
    Note: The writting of data is atomic if \fIbuf\fP.size()<=PIPE_BUF.
          If writting to a FIFO not opened for read on the other
          end, the process is send a SIGPIPE signal, see fifo(4).

    Note: The system buffer limits the bytes written. 
          Refer to system documents.
.PP
    [\fBRet\fP] Ok              Succeed
          Wym_EBADF       Object is not valid for the operation
          Wym_EINVAL      Object attatched device is not suitable
          Wym_EFBIG       Attempt to write beyond the device limit 
          Wym_EPIPE       Write to a pipe or FIFO with no reader
          Wym_EAGAIN      Non-blocking I/O (write would block)
          Wym_EINTR       Interrupted by a signal before data written
          Wym_ENOSPC      Device left no space for the operation
          Wym_EIO         Low level I/O error
.PP 
    [\fBRefer\fP] ::write(int,const void*,size_t)
.\"--------------------------------------------
.PP
.BI "static WyRet mkpipe(WyFifoFile& " "rd" ", WyFifoFile& " "wr" ")"
.PP
    Create a pipe, and reset \fIrd\fP for the read end, \fIwr\fP for the
    write end of the pipe.
.PP
    [\fBRet\fP] Ok              Succeed.
          Wym_EINVAL      \fIrd\fP, \fIwr\fP refer to the same object
          Wym_EMFILE      Too many open file descriptors
          Wym_ENFILE      File table is full
          ...             reply converted from the errno of ::pipe
.PP 
    [\fBRefer\fP] ::pipe(int fd[2])
.\"--------------------------------------------
.PP
.BI "static WyRet create(const char* " "pathname" ", mode_t " "m" ")"
.PP
.BI "static WyRet create(const WyStr& " "pathname" ", mode_t " "m" ")"
.PP
    Create a system FIFO file \fIpathname\fP with mode \fIm\fP
.PP
    [\fBRet\fP] Ok              Succeed.
          Wym_EACCES      Search permission is denied
          Wym_EEXIST      Pathname already exists
          Wym_ENAMETOOLONG Pathname too long
          Wym_ENOENT      A component in pathname does not exist
          Wym_ENOTDIR     A component in pathname is not a directory
          Wym_EROFS       Read-only file system
          Wym_ENOSPC      Device left no space for the operation
          Wym_ENOMEM      Not enough memory
          ...             reply converted from the errno of ::mkfifo
.PP 
    [\fBRefer\fP] ::mkfifo(const char*,mode_t)
.\"--------------------------------------------
.SH "SEE ALSO"
.BR wyret
.BR wyfilehandle
.BR wyfilestat
.BR wysockfile
.BR wyregfile
.BR wymutex
.BR wystr
.SH NOTE
Except added by this library, replys are converted from the errno 
an underlying C library function returned. Report of such replys
are brief from Linux Programmer's Manual. See the associated man page
for details.

Project is in development, http://sourceforge.net/projects/libwx