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04497f0b NW |
1 | /*- |
2 | * This code is derived from software copyrighted by the Free Software | |
3 | * Foundation. | |
4 | * | |
5 | * Modified 1991 by Donn Seeley at UUNET Technologies, Inc. | |
6 | * Modified 1990 by Van Jacobson at Lawrence Berkeley Laboratory. | |
7 | */ | |
8 | ||
9 | #ifndef lint | |
10 | static char sccsid[] = "@(#)environ.c 6.3 (Berkeley) 5/8/91"; | |
11 | #endif /* not lint */ | |
12 | ||
13 | /* environ.c -- library for manipulating environments for GNU. | |
14 | Copyright (C) 1986, 1989 Free Software Foundation, Inc. | |
15 | ||
16 | This program is free software; you can redistribute it and/or modify | |
17 | it under the terms of the GNU General Public License as published by | |
18 | the Free Software Foundation; either version 1, or (at your option) | |
19 | any later version. | |
20 | ||
21 | This program is distributed in the hope that it will be useful, | |
22 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
23 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
24 | GNU General Public License for more details. | |
25 | ||
26 | You should have received a copy of the GNU General Public License | |
27 | along with this program; if not, write to the Free Software | |
28 | Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ | |
29 | ||
30 | #define min(a, b) ((a) < (b) ? (a) : (b)) | |
31 | #define max(a, b) ((a) > (b) ? (a) : (b)) | |
32 | ||
33 | #include "environ.h" | |
34 | \f | |
35 | /* Return a new environment object. */ | |
36 | ||
37 | struct environ * | |
38 | make_environ () | |
39 | { | |
40 | register struct environ *e; | |
41 | ||
42 | e = (struct environ *) xmalloc (sizeof (struct environ)); | |
43 | ||
44 | e->allocated = 10; | |
45 | e->vector = (char **) xmalloc ((e->allocated + 1) * sizeof (char *)); | |
46 | e->vector[0] = 0; | |
47 | return e; | |
48 | } | |
49 | ||
50 | /* Free an environment and all the strings in it. */ | |
51 | ||
52 | void | |
53 | free_environ (e) | |
54 | register struct environ *e; | |
55 | { | |
56 | register char **vector = e->vector; | |
57 | ||
58 | while (*vector) | |
59 | free (*vector++); | |
60 | ||
61 | free (e); | |
62 | } | |
63 | ||
64 | /* Copy the environment given to this process into E. | |
65 | Also copies all the strings in it, so we can be sure | |
66 | that all strings in these environments are safe to free. */ | |
67 | ||
68 | void | |
69 | init_environ (e) | |
70 | register struct environ *e; | |
71 | { | |
72 | extern char **environ; | |
73 | register int i; | |
74 | ||
75 | for (i = 0; environ[i]; i++); | |
76 | ||
77 | if (e->allocated < i) | |
78 | { | |
79 | e->allocated = max (i, e->allocated + 10); | |
80 | e->vector = (char **) xrealloc (e->vector, | |
81 | (e->allocated + 1) * sizeof (char *)); | |
82 | } | |
83 | ||
84 | bcopy (environ, e->vector, (i + 1) * sizeof (char *)); | |
85 | ||
86 | while (--i >= 0) | |
87 | { | |
88 | register int len = strlen (e->vector[i]) + 1; | |
89 | register char *new = (char *) xmalloc (len); | |
90 | bcopy (e->vector[i], new, len); | |
91 | e->vector[i] = new; | |
92 | } | |
93 | } | |
94 | ||
95 | /* Return the vector of environment E. | |
96 | This is used to get something to pass to execve. */ | |
97 | ||
98 | char ** | |
99 | environ_vector (e) | |
100 | struct environ *e; | |
101 | { | |
102 | return e->vector; | |
103 | } | |
104 | \f | |
105 | /* Return the value in environment E of variable VAR. */ | |
106 | ||
107 | char * | |
108 | get_in_environ (e, var) | |
109 | struct environ *e; | |
110 | char *var; | |
111 | { | |
112 | register int len = strlen (var); | |
113 | register char **vector = e->vector; | |
114 | register char *s; | |
115 | ||
116 | for (; s = *vector; vector++) | |
117 | if (!strncmp (s, var, len) | |
118 | && s[len] == '=') | |
119 | return &s[len + 1]; | |
120 | ||
121 | return 0; | |
122 | } | |
123 | ||
124 | /* Store the value in E of VAR as VALUE. */ | |
125 | ||
126 | void | |
127 | set_in_environ (e, var, value) | |
128 | struct environ *e; | |
129 | char *var; | |
130 | char *value; | |
131 | { | |
132 | register int i; | |
133 | register int len = strlen (var); | |
134 | register char **vector = e->vector; | |
135 | register char *s; | |
136 | ||
137 | for (i = 0; s = vector[i]; i++) | |
138 | if (!strncmp (s, var, len) | |
139 | && s[len] == '=') | |
140 | break; | |
141 | ||
142 | if (s == 0) | |
143 | { | |
144 | if (i == e->allocated) | |
145 | { | |
146 | e->allocated += 10; | |
147 | vector = (char **) xrealloc (vector, | |
148 | (e->allocated + 1) * sizeof (char *)); | |
149 | e->vector = vector; | |
150 | } | |
151 | vector[i + 1] = 0; | |
152 | } | |
153 | else | |
154 | free (s); | |
155 | ||
156 | s = (char *) xmalloc (len + strlen (value) + 2); | |
157 | strcpy (s, var); | |
158 | strcat (s, "="); | |
159 | strcat (s, value); | |
160 | vector[i] = s; | |
161 | return; | |
162 | } | |
163 | ||
164 | /* Remove the setting for variable VAR from environment E. */ | |
165 | ||
166 | void | |
167 | unset_in_environ (e, var) | |
168 | struct environ *e; | |
169 | char *var; | |
170 | { | |
171 | register int len = strlen (var); | |
172 | register char **vector = e->vector; | |
173 | register char *s; | |
174 | ||
175 | for (; s = *vector; vector++) | |
176 | if (!strncmp (s, var, len) | |
177 | && s[len] == '=') | |
178 | { | |
179 | free (s); | |
180 | bcopy (vector + 1, vector, | |
181 | (e->allocated - (vector - e->vector)) * sizeof (char *)); | |
182 | e->vector[e->allocated - 1] = 0; | |
183 | return; | |
184 | } | |
185 | } |