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       link - make a new name for a file


       #include <unistd.h>

       int link(const char *oldpath, const char *newpath);


       link()  creates  a  new link (also known as a hard link) to an existing

       If newpath exists it will not be overwritten.

       This new name may be used exactly as the old  one  for  any  operation;
       both names refer to the same file (and so have the same permissions and
       ownership) and it is impossible to tell which name was the  "original".


       On  success,  zero is returned.  On error, -1 is returned, and errno is
       set appropriately.


       EACCES Write access to the directory containing newpath is  denied,  or
              search  permission  is  denied for one of the directories in the
              path   prefix   of    oldpath    or    newpath.     (See    also

       EEXIST newpath already exists.

       EFAULT oldpath or newpath points outside your accessible address space.

       EIO    An I/O error occurred.

       ELOOP  Too many symbolic links were encountered in resolving oldpath or

       EMLINK The  file  referred to by oldpath already has the maximum number
              of links to it.

              oldpath or newpath was too long.

       ENOENT A directory component in oldpath or newpath does not exist or is
              a dangling symbolic link.

       ENOMEM Insufficient kernel memory was available.

       ENOSPC The device containing the file has no room for the new directory

              A component used as a directory in oldpath or newpath is not, in
              fact, a directory.

       EPERM  oldpath is a directory.

       EPERM  The  file system containing oldpath and newpath does not support
              the creation of hard links.

       EROFS  The file is on a read-only file system.

       EXDEV  oldpath and newpath are not on the  same  mounted  file  system.
              (Linux  permits  a file system to be mounted at multiple points,
              but link() does not work across different mount points, even  if
              the same file system is mounted on both.)


       SVr4, 4.3BSD, POSIX.1-2001 (but see NOTES).


       Hard  links,  as  created  by  link(),  cannot  span file systems.  Use
       symlink(2) if this is required.

       POSIX.1-2001 says that link() should dereference oldpath  if  it  is  a
       symbolic  link.   However,  since  kernel 2.0, Linux does not do so: if
       oldpath is a symbolic link, then newpath is created as a (hard) link to
       the  same  symbolic link file (i.e., newpath becomes a symbolic link to
       the same file that oldpath  refers  to).   Some  other  implementations
       behave   in  the  same  manner  as  Linux.   POSIX.1-2008  changes  the
       specification of link(), making it implementation-dependent whether  or
       not  oldpath  is  dereferenced  if  it is a symbolic link.  For precise
       control over the treatment of symbolic links when creating a link,  see


       On  NFS  file  systems,  the  return  code may be wrong in case the NFS
       server performs the link creation and dies before it can say  so.   Use
       stat(2) to find out if the link got created.


       ln(1),  linkat(2),  open(2), rename(2), stat(2), symlink(2), unlink(2),
       path_resolution(7), symlink(7)


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