compiler/posixc/readlink.c

   1 /*
   2     Copyright © 1995-2013, 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 "__posixc_intbase.h"
  15 #include "__upath.h"
  16
  17 /*****************************************************************************
  18
  19     NAME */
  20 #include <unistd.h>
  21
  22         ssize_t readlink(
  23
  24 /*  SYNOPSIS */
  25         const char *path,
  26         char       *buf,
  27         size_t      bufsize)
  28
  29 /*  FUNCTION
  30         Places the contents of a symbolic link in a buffer of given size. No NUL
  31         char is appended to the buffer.
  32
  33     INPUTS
  34         path    - the path to the symbolic link
  35         buf     - pointer to the buffer where to store the symbolic link content
  36         bufsize - the size of the buffer in bytes
  37
  38     RESULT
  39         The call returns the count of characters placed in the buffer if it
  40         succeeds, or a -1 if an error occurs, placing the error code in the
  41         global variable errno.
  42 */
  43 {
  44     struct PosixCIntBase *PosixCBase =
  45         (struct PosixCIntBase *)__aros_getbase_PosixCBase();
  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 (PosixCBase->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     dvp = GetDeviceProc(path, NULL);
  63
  64     res = ReadLink(dvp->dvp_Port, dvp->dvp_Lock, path, buf, bufsize);
  65     if (res == -1) {
  66         error = IoErr();
  67     } else {
  68         if (res == -2)
  69             res = bufsize;
  70         error = me->pr_Result2 = 0;
  71     }
  72
  73     FreeDeviceProc(dvp);
  74
  75     if (error)
  76         errno = __stdc_ioerr2errno(error);
  77
  78     return res;
  79 }