From 28f540f45bbacd939bfd07f213bcad2bf730b1bf Mon Sep 17 00:00:00 2001 From: Roland McGrath Date: Sat, 18 Feb 1995 01:27:10 +0000 Subject: initial import --- sysdeps/mach/hurd/readlink.c | 76 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 76 insertions(+) create mode 100644 sysdeps/mach/hurd/readlink.c (limited to 'sysdeps/mach/hurd/readlink.c') 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 +#include +#include +#include +#include +#include + +/* 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) -- cgit 1.4.1