libcsupport/src/link.c

0001 /* SPDX-License-Identifier: BSD-2-Clause */
0002
0003 /**
0004  *  @file
0005  *
0006  *  @brief Create a new link
0007  *  @ingroup libcsupport
0008  */
0009
0010 /*
0011  *  COPYRIGHT (c) 1989-1999.
0012  *  On-Line Applications Research Corporation (OAR).
0013  *
0014  * Redistribution and use in source and binary forms, with or without
0015  * modification, are permitted provided that the following conditions
0016  * are met:
0017  * 1. Redistributions of source code must retain the above copyright
0018  *    notice, this list of conditions and the following disclaimer.
0019  * 2. Redistributions in binary form must reproduce the above copyright
0020  *    notice, this list of conditions and the following disclaimer in the
0021  *    documentation and/or other materials provided with the distribution.
0022  *
0023  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
0024  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
0025  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
0026  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
0027  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
0028  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
0029  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
0030  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
0031  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
0032  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
0033  * POSSIBILITY OF SUCH DAMAGE.
0034  */
0035
0036 #ifdef HAVE_CONFIG_H
0037 #include "config.h"
0038 #endif
0039
0040 #include <unistd.h>
0041
0042 #include <rtems/libio_.h>
0043
0044 /**
0045  *  link() - POSIX 1003.1b - 5.3.4 - Create a new link
0046  */
0047 int link( const char *path1, const char *path2 )
0048 {
0049   int rv = 0;
0050   rtems_filesystem_eval_path_context_t ctx_1;
0051   rtems_filesystem_eval_path_context_t ctx_2;
0052   int eval_flags_1 = RTEMS_FS_FOLLOW_LINK;
0053   int eval_flags_2 = RTEMS_FS_FOLLOW_LINK
0054     | RTEMS_FS_MAKE
0055     | RTEMS_FS_EXCLUSIVE;
0056   const rtems_filesystem_location_info_t *currentloc_1 =
0057     rtems_filesystem_eval_path_start( &ctx_1, path1, eval_flags_1 );
0058   const rtems_filesystem_location_info_t *currentloc_2 =
0059     rtems_filesystem_eval_path_start( &ctx_2, path2, eval_flags_2 );
0060
0061   rv = rtems_filesystem_location_exists_in_same_instance_as(
0062     currentloc_1,
0063     currentloc_2
0064   );
0065   if ( rv == 0 ) {
0066     rv = (*currentloc_2->mt_entry->ops->link_h)(
0067       currentloc_2,
0068       currentloc_1,
0069       rtems_filesystem_eval_path_get_token( &ctx_2 ),
0070       rtems_filesystem_eval_path_get_tokenlen( &ctx_2 )
0071     );
0072   }
0073
0074   rtems_filesystem_eval_path_cleanup( &ctx_1 );
0075   rtems_filesystem_eval_path_cleanup( &ctx_2 );
0076
0077   return rv;
0078 }
0079
0080 #if defined(RTEMS_NEWLIB)
0081
0082 #include <reent.h>
0083
0084 /**
0085  *  This is the Newlib dependent reentrant version of link().
0086  */
0087 int _link_r(
0088   struct _reent *ptr RTEMS_UNUSED,
0089   const char    *path1,
0090   const char    *path2
0091 )
0092 {
0093   return link( path1, path2 );
0094 }
0095 #endif