fpReadLink

Read destination of symbolic link

Declaration

Source position: line 0

function fpReadLink(

name: pchar;

linkname: pchar;

maxlen: size_t

):cint; function fpReadLink(

Name: ansistring

):ansistring;

Description

FpReadLink returns the file the symbolic link name is pointing to. The first form of this function accepts a buffer linkname of length maxlen where the filename will be stored. It returns the actual number of characters stored in the buffer.

The second form of the function returns simply the name of the file.

Errors

On error, the first form of the function returns -1; the second one returns an empty string. Extended error information is returned by the FpGetErrno function.

SYS_ENOTDIR: A part of the path in Name is not a directory.
SYS_EINVAL: maxlen is not positive, or the file is not a symbolic link.
SYS_ENAMETOOLONG: A pathname, or a component of a pathname, was too long.
SYS_ENOENT: the link name does not exist.
SYS_EACCES: No permission to search a directory in the path
SYS_ELOOP: Too many symbolic links were encountered in translating the pathname.
SYS_EIO: An I/O error occurred while reading from the file system.
SYS_EFAULT: The buffer is not part of the the process's memory space.
SYS_ENOMEM: Not enough kernel memory was available.

Example

Program Example62;

{ Program to demonstrate the ReadLink function. }

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 !');
  S:=fpReadLink('new.txt');
  If S='' then
    Writeln ('Error reading link !')
  Else
    Writeln ('Link points to : ',S);
 { Now remove links }
 If fpUnlink ('new.txt')<>0 then
   Writeln ('Error when unlinking !');
 If fpUnlink ('test.txt')<>0 then
   Writeln ('Error when unlinking !');
end.

Notes