wy_lnkfile.3wy

一个不错

.\"
.\" Edited by I.J.Wang, 2004
.\"
.TH Wy_LnkFile 3wy "libwy v0.31"
.SH NAME
Wy_LnkFile \- handle class of system link file
.SH SYNOPSIS
.B #include <wy_lnkfile.h>
.PP
[\fBInherit\fP]
.PP
Wy_LnkFile is a handle class for the system link file

Note: Implementation pretends a file descriptor was allocated,
      which is not true. The referred system link file may have
      been unlinked or modified while the object is in use.
.SH "PUBLIC MEMBERS"
 class \fBReply\fP : public WyRet
 \fBWy_LnkFile\fP()
 \fBWy_LnkFile\fP(const Wy_LnkFile&)
 \fBWy_LnkFile\fP(const char*)
 \fBWy_LnkFile\fP(const WyStr&)
 \fBWy_LnkFile\fP(Wy_LnkFile&, Wy::ByMove_t) throw()
 virtual \fB~Wy_LnkFile\fP()
 bool \fBis_default\fP(void) const throw()
 WyRet \fBstat\fP(WyFileStat&) const
 virtual WyRet \fBreset\fP(void)
 virtual WyRet \fBreset\fP(const Wy_LnkFile&)
 virtual WyRet \fBreset\fP(const char*)
 virtual WyRet \fBreset\fP(const WyStr&)
 virtual WyRet \fB_swap\fP(Wy_LnkFile&) throw()
 virtual Wy_LnkFile* \fB_alloc\fP(WyRet&) const
 virtual WyRet \fBread\fP(WyStr&)
 static WyRet \fBcreate\fP(const char*,const char*)
 static WyRet \fBcreate\fP(const char*,const WyStr&)
 static WyRet \fBcreate\fP(const WyStr&,const char*)
 static WyRet \fBcreate\fP(const WyStr&,const WyStr&)
.SH "DESCRIPTION"
.\"--------------------------------------------
.PP
.BI "class Reply : public WyRet
.PP
    Class specific throw type
.\"--------------------------------------------
.PP
.BI "Wy_LnkFile()"
.PP
    Construct default object (refers to nothing)
.PP
    [\fBThrow\fP] Reply
            Wym_ENOMEM      Not enough memory
.\"--------------------------------------------
.PP
.BI "Wy_LnkFile(const Wy_LnkFile& " "lnkf" ")"
.PP
    Construct object to handle the system file handled by \fIlnkf\fP.
.PP
    [\fBThrow\fP] Reply
            Wym_ENOMEM      Not enough memory
.\"--------------------------------------------
.PP
.BI "Wy_LnkFile(const char* " "pathname" ")"
.PP
.BI "Wy_LnkFile(const WyStr& " "pathname" ")"
.PP
    Construct object to handle the system file pointed by \fIpathname\fP
.PP
    [\fBThrow\fP] Reply
            Wym_ENODEV      \fIpathname\fP does not refer to a link
            Wym_EBADF       File is not valid for the operation
            Wym_EACCES      Search permission is denied
            Wym_ELOOP       Too many symbolic links encountered
            Wym_ENAMETOOLONG Pathname too long
            Wym_ENOENT      Pathname does not exist
            Wym_ENOTDIR     Entry in pathname is not a directory
            Wym_EIO         I/O error
            Wym_EFAULT      \fIpathname\fP is inaccessible
            Wym_ENOMEM      Not enough memory
            ...             [reserved]
.PP 
    [\fBRefer\fP] ::lstat(const char*,struct stat*)
.\"--------------------------------------------
.PP
.BI "Wy_LnkFile(Wy_LnkFile& " "src" ", Wy::ByMove_t) throw()"
.PP
    See Wy_Array(Wy_Array&, Wy::ByMove_t) in wy_array(3wy)
    for definition of the move constructor.
.\"--------------------------------------------
.PP
.BI "virtual ~Wy_LnkFile()"
.PP
    Destruct *this
.PP
    Note: This member is non-cancellable.
.\"--------------------------------------------
.PP
.BI "bool is_default(void) const throw()"
.TP
    Is *this equivalent to the default object
.PP
    [\fBRet\fP] true= object is equivalent to the default one.
         false= otherwise
.\"--------------------------------------------
.PP
.BI "WyRet stat(WyFileStat& " "filestat" ") const" 
.PP
    Reset \fIfilestat\fP with the file information *this associates

    Note: The link itself is reffered, not the linked file.
.PP
    [\fBRet\fP] Ok              Succeed.
          Wym_EBADF       Object is default
          Wym_ENOMEM      Not enough memory
          ...             reply converted from ::lstat returned
.PP 
    [\fBRefer\fP] ::lstat(int,struct stat)
.\"--------------------------------------------
.PP
.BI "virtual WyRet reset(void)" 
.PP
    Reconstruct *this to the state as Wy_LnkFile()
.PP
    [\fBRet\fP] Ok              Succeed.
          ...
    
    Note: Object is always default while returned.
.\"--------------------------------------------
.PP
.BI "virtual WyRet reset(const Wy_LnkFile& " "lnkf" ")" 
.PP
    Reconstruct *this to the state as Wy_LnkFile(\fIlnkf\fP)
.PP
    [\fBRet\fP] Ok              Succeed.
          Wym_ENOMEM      Not enough memory
          ...             [reserved]

    Note: Error report from closing the previously handled
          object is ignored. Use reset() first if the close
          return status is desired
.\"--------------------------------------------
.PP
.BI "virtual WyRet reset(const char* " "pathname" ")" 
.PP
.BI "virtual WyRet reset(const WyStr& " "pathname" ")" 
.PP
    Reconstruct *this to the state as Wy_LnkFile(\fIpathname\fP)
.PP
    [\fBRet\fP] Ok              Succeed.
          Wym_ENODEV      \fIpathname\fP does not refer to a link
          Wym_EBADF       File is not valid for the operation
          Wym_EACCES      Search permission is denied
          Wym_ELOOP       Too many symbolic links encountered
          Wym_ENAMETOOLONG Pathname too long
          Wym_ENOENT      Pathname does not exist
          Wym_ENOTDIR     A component in pathname is not a directory
          Wym_EIO         I/O error
          Wym_ENOMEM      Not enough memory
          ...             [reserved]

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

    Note: Inhertied class must override this member

    \fIr\fP is reset with the return status:
            Wym_ENOMEM      Not enough memory
            ...             Same from constructing Wy_LnkFile()
.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(WyStr& " "value" ")" 
.PP
    Read the value of the link object and reset \fIvalue\fP with
    the result.
.PP
    Note: Implementation pretends a file descriptor was allocated,
          which is not true. The referred system link file may have
          been unlinked.
.PP
    [\fBRet\fP] Ok              Succeed.
          Wym_EBADF       Object is default
          Wym_ENOMEM      Not enough memory
          .....           reply converted from ::readlink
.PP 
    [\fBRefer\fP] ::readlink
.\"--------------------------------------------
.PP
.BI "static WyRet create(const char* " "oldpath" ",const char* " "newpath" ")"
.PP
.BI "static WyRet create(const char* " "oldpath" ",const WyStr& " "newpath" ")"
.PP
.BI "static WyRet create(const WyStr& " "oldpath" ",const char* " "newpath" ")"
.PP
.BI "static WyRet create(const WyStr& " "oldpath" ",const WyStr& " "newpath" ")"
.PP
    Create a symbolic link file \fInewpath\fP which contains the value 
    \fInewpath\fP.
.PP
    [\fBRet\fP] Ok              Succeed.
          Wym_EACCESS     Access is not allowed
          Wym_EPERM       Operation not permitted
          Wym_ENAMETOOLONG \fInewpath\fP or \fIoldpath\fP too long
          Wym_ENOENT      A component in the pathnames does not exist
          Wym_ENOTDIR     A component in the pathnames is not a directory
          Wym_ENOMEM      Not enough memory
          Wym_EROFS       Refers to a file in a read-only filesystem
          Wym_EEXIST      \fInewpath\fP already exist
          Wym_ELOOP       Too many symbolic encountered
          Wym_ENOSPC      No space left for the pathname.
          Wym_EIO         I/O error
          ....            reply converted from the errno ::symlink
 
    [\fBRefer\fP] ::symlink(const char*,const char*)
.\"--------------------------------------------
.SH "SEE ALSO"
.BR wyfilestat
.BR wychrfile
.BR wy_dirfile
.BR wy
.BR wystr
.BR wymutex
.BR wytimespec
.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