posix/src/sysconf.c

0001 /* SPDX-License-Identifier: BSD-2-Clause */
0002
0003 /**
0004  * @file
0005  *
0006  * @ingroup POSIXAPI
0007  *
0008  * @brief Get Configurable System Variables
0009  */
0010
0011 /*
0012  *  COPYRIGHT (c) 1989-2007.
0013  *  On-Line Applications Research Corporation (OAR).
0014  *
0015  * Redistribution and use in source and binary forms, with or without
0016  * modification, are permitted provided that the following conditions
0017  * are met:
0018  * 1. Redistributions of source code must retain the above copyright
0019  *    notice, this list of conditions and the following disclaimer.
0020  * 2. Redistributions in binary form must reproduce the above copyright
0021  *    notice, this list of conditions and the following disclaimer in the
0022  *    documentation and/or other materials provided with the distribution.
0023  *
0024  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
0025  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
0026  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
0027  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
0028  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
0029  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
0030  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
0031  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
0032  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
0033  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
0034  * POSSIBILITY OF SUCH DAMAGE.
0035  */
0036
0037 #ifdef HAVE_CONFIG_H
0038 #include "config.h"
0039 #endif
0040
0041 #include <time.h>
0042 #include <unistd.h>
0043 #include <errno.h>
0044
0045 #include <rtems.h>
0046 #include <rtems/seterr.h>
0047 #include <rtems/libio_.h>
0048
0049 #include <sys/param.h>
0050
0051 /*
0052  *  4.8.1 Get Configurable System Variables, P1003.1b-1993, p. 95
0053  */
0054
0055 long sysconf(
0056   int name
0057 )
0058 {
0059   switch ( name ) {
0060     case _SC_CLK_TCK:
0061       return (long) rtems_clock_get_ticks_per_second();
0062     case _SC_OPEN_MAX:
0063       return rtems_libio_number_iops;
0064     case _SC_GETPW_R_SIZE_MAX:
0065       return 1024;
0066     case _SC_PAGESIZE:
0067       return PAGE_SIZE;
0068     case _SC_SYMLOOP_MAX:
0069       return RTEMS_FILESYSTEM_SYMLOOP_MAX;
0070     case _SC_NPROCESSORS_CONF:
0071       return (long) rtems_configuration_get_maximum_processors();
0072     case _SC_NPROCESSORS_ONLN:
0073       return (long) rtems_scheduler_get_processor_maximum();
0074     case _SC_POSIX_26_VERSION:
0075       return (long) _POSIX_26_VERSION;
0076     default:
0077       rtems_set_errno_and_return_minus_one( EINVAL );
0078   }
0079 }