LINK(2)             Linux Programmer's Manual             LINK(2)

       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 file.

       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.

       EXDEV   oldpath and newpath are not on the  same  filesys-

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

       EFAULT  oldpath or newpath points outside your  accessible
               address space.

       EACCES  Write  access  to the directory containing newpath
               is not allowed for the process's effective uid, or
               one  of  the directories in oldpath or newpath did
               not allow search (execute) permission.

               oldpath or newpath was too long.

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

       ENOTDIR A component used as a directory in oldpath or new-
               path is not, in fact, a directory.

       ENOMEM  Insufficient kernel memory was available.

       EROFS   The file is on a read-only filesystem.

       EEXIST  newpath already exists.

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

       ELOOP   Too   many  symbolic  links  were  encountered  in
               resolving oldpath or newpath.

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

       EPERM   oldpath is a directory.

       EIO     An I/O error occurred.

       Hard  links,  as created by link, cannot span filesystems.
       Use symlink if this is required.

       SVr4, SVID, POSIX, BSD 4.3, X/OPEN.  SVr4 documents  addi-
       tional  ENOLINK  and  EMULTIHOP  error conditions; POSIX.1
       does not document ELOOP.  X/OPEN does not document EFAULT,
       ENOMEM or EIO.

       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

       symlink(2), unlink(2), rename(2), open(2), stat(2), ln(1)

Linux 2.0.30             10 December 1997                       1