Man Linkat en anglais
LINKAT(2)                  Linux Programmer's Manual                 LINKAT(2)



 

NAME


       linkat - create a file link relative to directory file descriptors

 

SYNOPSIS


       #define _ATFILE_SOURCE
       #include  /* Definition of AT_* constants */
       #include 

       int linkat(int olddirfd, const char *oldpath,
                  int newdirfd, const char *newpath, int flags);

 

DESCRIPTION






       The  linkat()  system call operates in exactly the same way as link(2),
       except for the differences described in this manual page.

       If the pathname given in oldpath is relative, then  it  is  interpreted
       relative  to  the directory referred to by the file descriptor olddirfd
       (rather than relative to the current working directory of  the  calling
       process, as is done by link(2) for a relative pathname).

       If oldpath is relative and olddirfd is the special value AT_FDCWD, then
       oldpath is interpreted relative to the current working directory of the
       calling process (like link(2)).

       If oldpath is absolute, then olddirfd is ignored.

       The interpretation of newpath is as for oldpath, except that a relative
       pathname is interpreted relative to the directory referred  to  by  the
       file descriptor newdirfd.

       By  default, linkat(), does not dereference oldpath if it is a symbolic
       link (like link(2)).  Since Linux 2.6.18,  the  flag  AT_SYMLINK_FOLLOW
       can  be specified in flags to cause oldpath to be dereferenced if it is
       a symbolic link.  Before kernel 2.6.18, the flags argument was  unused,
       and had to be specified as 0.

 

RETURN VALUE


       On  success, linkat() returns 0.  On error, -1 is returned and errno is
       set to indicate the error.

 

ERRORS


       The same errors that occur for link(2) can  also  occur  for  linkat().
       The following additional errors can occur for linkat():

       EBADF  olddirfd or newdirfd is not a valid file descriptor.

 

       ENOTDIR


              oldpath  is relative and olddirfd is a file descriptor referring
              to a file other than a directory; or  similar  for  newpath  and
              newdirfd

 

VERSIONS


       linkat() was added to Linux in kernel 2.6.16.

 

CONFORMING TO


       This  system  call  is  non-standard but is proposed for inclusion in a
       future revision of POSIX.1.

 

NOTES


       See openat(2) for an explanation of the need for linkat().

 

SEE ALSO


       link(2), openat(2), path_resolution(7), symlink(7)

 

COLOPHON


       This page is part of release 3.05 of the Linux  man-pages  project.   A
       description  of  the project, and information about reporting bugs, can
       be found at http://www.kernel.org/doc/man-pages/.



Linux                             2006-04-10                         LINKAT(2)