var.h

操作系统源代码

/*-
 * Copyright (c) 1991 The Regents of the University of California.
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Kenneth Almquist.
 *
 * 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.
 *
 *	@(#)var.h	5.1 (Berkeley) 3/7/91
 */

/*
 * Shell variables.
 */

/* flags */
#define VEXPORT		01	/* variable is exported */
#define VREADONLY	02	/* variable cannot be modified */
#define VSTRFIXED	04	/* variable struct is staticly allocated */
#define VTEXTFIXED	010	/* text is staticly allocated */
#define VSTACK		020	/* text is allocated on the stack */
#define VUNSET		040	/* the variable is not set */


struct var {
	struct var *next;		/* next entry in hash list */
	int flags;		/* flags are defined above */
	char *text;		/* name=value */
};


struct localvar {
	struct localvar *next;	/* next local variable in list */
	struct var *vp;		/* the variable that was made local */
	int flags;		/* saved flags */
	char *text;		/* saved text */
};


struct localvar *localvars;

#if ATTY
extern struct var vatty;
#endif
extern struct var vifs;
extern struct var vmail;
extern struct var vmpath;
extern struct var vpath;
extern struct var vps1;
extern struct var vps2;
extern struct var vpse;
#if ATTY
extern struct var vterm;
#endif

/*
 * The following macros access the values of the above variables.
 * They have to skip over the name.  They return the null string
 * for unset variables.
 */

#define ifsval()	(vifs.text + 4)
#define mailval()	(vmail.text + 5)
#define mpathval()	(vmpath.text + 9)
#define pathval()	(vpath.text + 5)
#define ps1val()	(vps1.text + 4)
#define ps2val()	(vps2.text + 4)
#define pseval()	(vpse.text + 4)
#if ATTY
#define termval()	(vterm.text + 5)
#endif

#if ATTY
#define attyset()	((vatty.flags & VUNSET) == 0)
#endif
#define mpathset()	((vmpath.flags & VUNSET) == 0)


#ifdef __STDC__
void initvar();
void setvar(char *, char *, int);
void setvareq(char *, int);
struct strlist;
void listsetvar(struct strlist *);
char *lookupvar(char *);
char *bltinlookup(char *, int);
char **environment();
int showvarscmd(int, char **);
void mklocal(char *);
void poplocalvars(void);
#else
void initvar();
void setvar();
void setvareq();
void listsetvar();
char *lookupvar();
char *bltinlookup();
char **environment();
int showvarscmd();
void mklocal();
void poplocalvars();
#endif