fpSymlink

Create a symbolic link

Declaration

Source position: bunxh.inc line 101

  function fpSymlink(oldname: pchar; newname: pchar) : cint;

Description

SymLink makes NewName point to the file in OldName, which doesn't necessarily exist. The two files DO NOT have the same inode number. This is known as a 'soft' link.

The permissions of the link are irrelevant, as they are not used when following the link. Ownership of the file is only checked in case of removal or renaming of the link.

The function returns zero if the call was successful, a nonzero value if the call failed.

Errors

Extended error information is returned by the FpGetErrno function.

sys_eperm

The file system containing oldpath and newpath does not support linking files.

sys_eaccess

Write access for the directory containing Newpath is disallowed, or one of the directories in OldPath or NewPath has no search (=execute) permission.

sys_enoent

A directory entry in OldPath or NewPath does not exist or is a symbolic link pointing to a non-existent directory.

sys_enotdir

A directory entry in OldPath or NewPath is nor a directory.

sys_enomem

Insufficient kernel memory.

sys_erofs

The files are on a read-only file system.

sys_eexist

NewPath already exists.

sys_eloop

OldPath or NewPath has a reference to a circular symbolic link, i.e. a symbolic link, whose expansion points to itself.

sys_enospc

The device containing NewPath has no room for another entry.

See also

Name	Description
FpLink	Create a hard link to a file
FpReadLink	Read destination of symbolic link
FpUnLink	Unlink (i.e. remove) a file.

Example

Program Example22;
{ Program to demonstrate the SymLink and UnLink functions. }
Uses baseunix,Unix;
Var F : Text;
    S : String;
begin
  Assign (F,'test.txt');
  Rewrite (F);
  Writeln (F,'This is written to test.txt');
  Close(f);
  { new.txt and test.txt are now the same file }
  if fpSymLink ('test.txt','new.txt')<>0 then
    writeln ('Error when symlinking !');
  { Removing test.txt still leaves new.txt
    Pointing now to a non-existent file ! }
  If fpUnlink ('test.txt')<>0 then
    Writeln ('Error when unlinking !');
  Assign (f,'new.txt');
  { This should fail, since the symbolic link
    points to a non-existent file! }
  {$i-}
  Reset (F);
  {$i+}
  If IOResult=0 then
    Writeln ('This shouldn''t happen');
 { Now remove new.txt also }
 If fpUnlink ('new.txt')<>0 then
   Writeln ('Error when unlinking !');
end.