3.3.5 Procedure 5: READLINK - Read from symbolic link

SYNOPSIS

      READLINK3res NFSPROC3_READLINK(READLINK3args) = 5;

      struct READLINK3args {
           nfs_fh3  symlink;
      };

      struct READLINK3resok {
           post_op_attr   symlink_attributes;
           nfspath3       data;
      };

      struct READLINK3resfail {
           post_op_attr   symlink_attributes;
      };

      union READLINK3res switch (nfsstat3 status) {
      case NFS3_OK:
           READLINK3resok   resok;
      default:
           READLINK3resfail resfail;
      };

DESCRIPTION

Procedure READLINK reads the data associated with a symbolic link. The data is an ASCII string that is opaque to the server. That is, whether created by the NFS version 3 protocol software from a client or created locally on the server, the data in a symbolic link is not interpreted when created, but is simply stored. On entry, the arguments in READLINK3args are:

symlink

The file handle for a symbolic link (file system object of type NF3LNK).

On successful return, READLINK3res.status is NFS3_OK and READLINK3res.resok contains:

data

The data associated with the symbolic link.

symlink_attributes

The post-operation attributes for the symbolic link.

Otherwise, READLINK3res.status contains the error on failure and READLINK3res.resfail contains the following:

symlink_attributes

The post-operation attributes for the symbolic link.

IMPLEMENTATION

A symbolic link is nominally a pointer to another file. The data is not necessarily interpreted by the server, just stored in the file. It is possible for a client implementation to store a path name that is not meaningful to the server operating system in a symbolic link. A READLINK operation returns the data to the client for interpretation. If different implementations want to share access to symbolic links, then they must agree on the interpretation of the data in the symbolic link.

The READLINK operation is only allowed on objects of type, NF3LNK. The server should return the error, NFS3ERR_INVAL, if the object is not of type, NF3LNK. (Note: The X/Open XNFS Specification for the NFS version 2 protocol defined the error status in this case as NFSERR_NXIO. This is inconsistent with existing server practice.)

ERRORS

NFS3ERR_IO NFS3ERR_INVAL NFS3ERR_ACCES NFS3ERR_STALE NFS3ERR_BADHANDLE NFS3ERR_NOTSUPP NFS3ERR_SERVERFAULT

SEE ALSO READLINK, SYMLINK.