compiler/clib/readlink.c

   1 /*
   2     Copyright © 1995-2012, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     POSIX.1-2008 function readlink().
   6 */
   7
   8 #include <aros/debug.h>
   9
  10 #include <proto/dos.h>
  11
  12 #include <errno.h>
  13
  14 #include "__arosc_privdata.h"
  15 #include "__filesystem_support.h"
  16 #include "__upath.h"
  17
  18 /*****************************************************************************
  19
  20     NAME */
  21 #include <unistd.h>
  22
  23         ssize_t readlink(
  24
  25 /*  SYNOPSIS */
  26         const char *path,
  27         char       *buf,
  28         size_t      bufsize)
  29
  30 /*  FUNCTION
  31         Places the contents of a symbolic link in a buffer of given size. No NUL
  32         char is appended to the buffer.
  33
  34     INPUTS
  35         path    - the path to the symbolic link
  36         buf     - pointer to the buffer where to store the symbolic link content
  37         bufsize - the size of the buffer in bytes
  38
  39     RESULT
  40         The call returns the count of characters placed in the buffer if it
  41         succeeds, or a -1 if an error occurs, placing the error code in the
  42         global variable errno.
  43 */
  44 {
  45     struct aroscbase *aroscbase = __aros_getbase();
  46     ssize_t          res = -1;
  47     struct DevProc   *dvp = NULL;
  48     LONG             error;
  49     struct Process   *me = (struct Process *)FindTask(NULL);
  50
  51     /* check for empty path before potential conversion from "." to "" */
  52     if (aroscbase->acb_doupath && path && *path == '\0')
  53     {
  54         errno = ENOENT;
  55         return res;
  56     }
  57
  58     path = __path_u2a(path);
  59     if (path == NULL)
  60         return res;
  61
  62     res = ReadLink(dvp->dvp_Port, dvp->dvp_Lock, path, buf, bufsize);
  63     if (res == -1) {
  64         error = IoErr();
  65     } else {
  66         if (res == -2)
  67             res = bufsize;
  68         error = me->pr_Result2 = 0;
  69     }
  70
  71     FreeDeviceProc(dvp);
  72
  73     if (error)
  74         errno = __arosc_ioerr2errno(error);
  75
  76     return res;
  77 }