__unistd.h

介绍：MySQL是比较出名的数据库软件

/*-
 * Copyright (c) 1990 The Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *	from: @(#)stdlib.h	5.13 (Berkeley) 6/4/91
 *	__unistd.h,v 1.1 1995/01/03 12:53:35 proven Exp
 */

#ifndef _SYS___UNISTD_H_
#define _SYS___UNISTD_H_

#include <sys/types.h>

#ifndef	NULL
#define	NULL	0
#endif

/* compile-time symbolic constants */
#define	_POSIX_JOB_CONTROL	/* implementation supports job control */

#ifdef	_NOT_AVAILABLE
#define	_POSIX_SAVED_IDS	/* saved set-user-ID and set-group-ID */
#endif

#define	_POSIX_VERSION		198808L
#define	_POSIX2_VERSION		199212L

/* execution-time symbolic constants */
				/* chown requires appropriate privileges */
#define	_POSIX_CHOWN_RESTRICTED	1
				/* too-long path components generate errors */
#define	_POSIX_NO_TRUNC		1
				/* may disable terminal special characters */
#define	_POSIX_VDISABLE		((unsigned char)'\377')

/* configurable pathname variables */
#define	_PC_LINK_MAX		 1
#define	_PC_MAX_CANON		 2
#define	_PC_MAX_INPUT		 3
#define	_PC_NAME_MAX		 4
#define	_PC_PATH_MAX		 5
#define	_PC_PIPE_BUF		 6
#define	_PC_CHOWN_RESTRICTED	 7
#define	_PC_NO_TRUNC		 8
#define	_PC_VDISABLE		 9

/* configurable system variables */
#define	_SC_ARG_MAX		 1
#define	_SC_CHILD_MAX		 2
#define	_SC_CLK_TCK		 3
#define	_SC_NGROUPS_MAX		 4
#define	_SC_OPEN_MAX		 5
#define	_SC_JOB_CONTROL		 6
#define	_SC_SAVED_IDS		 7
#define	_SC_VERSION		 8
#define	_SC_BC_BASE_MAX		 9
#define	_SC_BC_DIM_MAX		10
#define	_SC_BC_SCALE_MAX	11
#define	_SC_BC_STRING_MAX	12
#define	_SC_COLL_WEIGHTS_MAX	13
#define	_SC_EXPR_NEST_MAX	14
#define	_SC_LINE_MAX		15
#define	_SC_RE_DUP_MAX		16
#define	_SC_2_VERSION		17
#define	_SC_2_C_BIND		18
#define	_SC_2_C_DEV		19
#define	_SC_2_CHAR_TERM		20
#define	_SC_2_FORT_DEV		21
#define	_SC_2_FORT_RUN		22
#define	_SC_2_LOCALEDEF		23
#define	_SC_2_SW_DEV		24
#define	_SC_2_UPE		25
#define	_SC_STREAM_MAX		26
#define	_SC_TZNAME_MAX		27

/* configurable system strings */
#define	_CS_PATH		 1

#endif