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Diffstat (limited to 'sysdeps/mach/hurd/readlink.c')
-rw-r--r--sysdeps/mach/hurd/readlink.c76
1 files changed, 76 insertions, 0 deletions
diff --git a/sysdeps/mach/hurd/readlink.c b/sysdeps/mach/hurd/readlink.c
new file mode 100644
index 0000000000..2f51e200b5
--- /dev/null
+++ b/sysdeps/mach/hurd/readlink.c
@@ -0,0 +1,76 @@
+/* Copyright (C) 1991, 1992, 1993, 1994, 1995 Free Software Foundation, Inc.
+This file is part of the GNU C Library.
+
+The GNU C Library is free software; you can redistribute it and/or
+modify it under the terms of the GNU Library General Public License as
+published by the Free Software Foundation; either version 2 of the
+License, or (at your option) any later version.
+
+The GNU C Library is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+Library General Public License for more details.
+
+You should have received a copy of the GNU Library General Public
+License along with the GNU C Library; see the file COPYING.LIB. If
+not, write to the Free Software Foundation, Inc., 675 Mass Ave,
+Cambridge, MA 02139, USA. */
+
+#include <ansidecl.h>
+#include <unistd.h>
+#include <hurd.h>
+#include <hurd/paths.h>
+#include <fcntl.h>
+#include <string.h>
+
+/* Read the contents of the symbolic link FILE_NAME into no more than
+ LEN bytes of BUF. The contents are not null-terminated.
+ Returns the number of characters read, or -1 for errors. */
+ssize_t
+DEFUN(__readlink, (file_name, buf, len),
+ CONST char *file_name AND char *buf AND size_t len)
+{
+ error_t err;
+ file_t file;
+ char mybuf[2048], *transp = mybuf;
+ mach_msg_type_number_t translen = sizeof (mybuf);
+
+ file = __file_name_lookup (file_name, O_NOTRANS, 0);
+ if (file == MACH_PORT_NULL)
+ return -1;
+
+ err = __file_get_translator (file, &transp, &translen);
+ __mach_port_deallocate (__mach_task_self (), file);
+
+ if (err)
+ return __hurd_fail (err);
+
+ if (translen < sizeof (_HURD_SYMLINK) ||
+ memcmp (transp, _HURD_SYMLINK, sizeof (_HURD_SYMLINK)))
+ /* The file is not actually a symlink. */
+ err = EINVAL;
+ else
+ {
+ /* This is a symlink; its translator is "/hurd/symlink\0target\0". */
+ if (len >= translen - sizeof (_HURD_SYMLINK))
+ {
+ len = translen - sizeof (_HURD_SYMLINK);
+ if (transp[translen - 1] == '\0')
+ /* Remove the null terminator. */
+ --len;
+ }
+ if (buf == NULL)
+ /* This call is just to find out how large a buffer is required. */
+ len = translen - sizeof (_HURD_SYMLINK) - 1;
+ else
+ /* Copy into the user's buffer. */
+ memcpy (buf, transp + sizeof (_HURD_SYMLINK), len);
+ }
+
+ if (transp != mybuf)
+ __vm_deallocate (__mach_task_self (), (vm_address_t) transp, translen);
+
+ return err ? __hurd_fail (err) : len;
+}
+
+weak_alias (__readlink, readlink)