| 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 | } |