1 /*-
2  * Copyright (c) 1991, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  * Copyright (c) 1997-2005
5  *	Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
6  *
7  * This code is derived from software contributed to Berkeley by
8  * Kenneth Almquist.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. Neither the name of the University nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  *
34  *	@(#)var.h	8.2 (Berkeley) 5/4/95
35  */
36 
37 #include <inttypes.h>
38 
39 /*
40  * Shell variables.
41  */
42 
43 /* flags */
44 #define VEXPORT		0x01	/* variable is exported */
45 #define VREADONLY	0x02	/* variable cannot be modified */
46 #define VSTRFIXED	0x04	/* variable struct is statically allocated */
47 #define VTEXTFIXED	0x08	/* text is statically allocated */
48 #define VSTACK		0x10	/* text is allocated on the stack */
49 #define VUNSET		0x20	/* the variable is not set */
50 #define VNOFUNC		0x40	/* don't call the callback function */
51 #define VNOSET		0x80	/* do not set variable - just readonly test */
52 #define VNOSAVE		0x100	/* when text is on the heap before setvareq */
53 
54 
55 struct var {
56 	struct var *next;		/* next entry in hash list */
57 	int flags;			/* flags are defined above */
58 	const char *text;		/* name=value */
59 	void (*func)(const char *);
60 					/* function to be called when  */
61 					/* the variable gets set/unset */
62 };
63 
64 
65 struct localvar {
66 	struct localvar *next;		/* next local variable in list */
67 	struct var *vp;			/* the variable that was made local */
68 	int flags;			/* saved flags */
69 	const char *text;		/* saved text */
70 };
71 
72 struct localvar_list;
73 
74 
75 extern struct localvar *localvars;
76 extern struct var varinit[];
77 
78 #if ATTY
79 #define vatty varinit[0]
80 #define vifs varinit[1]
81 #else
82 #define vifs varinit[0]
83 #endif
84 #define vpath (&vifs)[1]
85 #define vps1 (&vpath)[1]
86 #define vps2 (&vps1)[1]
87 #define vps4 (&vps2)[1]
88 #define voptind (&vps4)[1]
89 #ifdef WITH_LINENO
90 #define vlineno (&voptind)[1]
91 #endif
92 
93 #ifdef IFS_BROKEN
94 extern const char defifsvar[];
95 #define defifs (defifsvar + 4)
96 #else
97 extern const char defifs[];
98 #endif
99 extern const char defpathvar[];
100 #define defpath (&defpathvar[sizeof("PATH=") - 1])
101 
102 extern int lineno;
103 extern char linenovar[];
104 
105 /*
106  * The following macros access the values of the above variables.
107  * They have to skip over the name.  They return the null string
108  * for unset variables.
109  */
110 
111 #define ifsval()	(vifs.text + 4)
112 #define ifsset()	((vifs.flags & VUNSET) == 0)
113 #define mailval()	(vmail.text + 5)
114 #define mpathval()	(vmpath.text + 9)
115 #define pathval()	(vpath.text + 5)
116 #define ps1val()	(vps1.text + 4)
117 #define ps2val()	(vps2.text + 4)
118 #define ps4val()	(vps4.text + 4)
119 #define optindval()	(voptind.text + 7)
120 #define linenoval()	(vlineno.text + 7)
121 
122 #if ATTY
123 #define attyset()	((vatty.flags & VUNSET) == 0)
124 #endif
125 #define mpathset()	((vmpath.flags & VUNSET) == 0)
126 
127 void initvar(void);
128 struct var *setvar(const char *name, const char *val, int flags);
129 intmax_t setvarint(const char *, intmax_t, int);
130 struct var *setvareq(char *s, int flags);
131 struct strlist;
132 void listsetvar(struct strlist *, int);
133 char *lookupvar(const char *);
134 intmax_t lookupvarint(const char *);
135 char **listvars(int, int, char ***);
136 #define environment() listvars(VEXPORT, VUNSET, 0)
137 int showvars(const char *, int, int);
138 int exportcmd(int, char **);
139 int localcmd(int, char **);
140 void mklocal(char *);
141 struct localvar_list *pushlocalvars(void);
142 void poplocalvars(int);
143 void unwindlocalvars(struct localvar_list *stop);
144 int unsetcmd(int, char **);
145 void unsetvar(const char *);
146 int varcmp(const char *, const char *);
147 
varequal(const char * a,const char * b)148 static inline int varequal(const char *a, const char *b) {
149 	return !varcmp(a, b);
150 }
151 
152 /*
153  * Search the environment of a builtin command.
154  */
155 
bltinlookup(const char * name)156 static inline char *bltinlookup(const char *name)
157 {
158 	return lookupvar(name);
159 }
160 
161 
162