| 1 | /* environ.c -- library for manipulating environments for GNU. |
| 2 | |
| 3 | Copyright (C) 1986-2016 Free Software Foundation, Inc. |
| 4 | |
| 5 | This program is free software; you can redistribute it and/or modify |
| 6 | it under the terms of the GNU General Public License as published by |
| 7 | the Free Software Foundation; either version 3 of the License, or |
| 8 | (at your option) any later version. |
| 9 | |
| 10 | This program is distributed in the hope that it will be useful, |
| 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 13 | GNU General Public License for more details. |
| 14 | |
| 15 | You should have received a copy of the GNU General Public License |
| 16 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
| 17 | |
| 18 | #include "defs.h" |
| 19 | #include "environ.h" |
| 20 | #include <algorithm> |
| 21 | \f |
| 22 | |
| 23 | /* Return a new environment object. */ |
| 24 | |
| 25 | struct gdb_environ * |
| 26 | make_environ (void) |
| 27 | { |
| 28 | struct gdb_environ *e; |
| 29 | |
| 30 | e = XNEW (struct gdb_environ); |
| 31 | |
| 32 | e->allocated = 10; |
| 33 | e->vector = (char **) xmalloc ((e->allocated + 1) * sizeof (char *)); |
| 34 | e->vector[0] = 0; |
| 35 | return e; |
| 36 | } |
| 37 | |
| 38 | /* Free an environment and all the strings in it. */ |
| 39 | |
| 40 | void |
| 41 | free_environ (struct gdb_environ *e) |
| 42 | { |
| 43 | char **vector = e->vector; |
| 44 | |
| 45 | while (*vector) |
| 46 | xfree (*vector++); |
| 47 | |
| 48 | xfree (e->vector); |
| 49 | xfree (e); |
| 50 | } |
| 51 | |
| 52 | /* Copy the environment given to this process into E. |
| 53 | Also copies all the strings in it, so we can be sure |
| 54 | that all strings in these environments are safe to free. */ |
| 55 | |
| 56 | void |
| 57 | init_environ (struct gdb_environ *e) |
| 58 | { |
| 59 | extern char **environ; |
| 60 | int i; |
| 61 | |
| 62 | if (environ == NULL) |
| 63 | return; |
| 64 | |
| 65 | for (i = 0; environ[i]; i++) /*EMPTY */ ; |
| 66 | |
| 67 | if (e->allocated < i) |
| 68 | { |
| 69 | e->allocated = std::max (i, e->allocated + 10); |
| 70 | e->vector = (char **) xrealloc ((char *) e->vector, |
| 71 | (e->allocated + 1) * sizeof (char *)); |
| 72 | } |
| 73 | |
| 74 | memcpy (e->vector, environ, (i + 1) * sizeof (char *)); |
| 75 | |
| 76 | while (--i >= 0) |
| 77 | { |
| 78 | int len = strlen (e->vector[i]); |
| 79 | char *newobj = (char *) xmalloc (len + 1); |
| 80 | |
| 81 | memcpy (newobj, e->vector[i], len + 1); |
| 82 | e->vector[i] = newobj; |
| 83 | } |
| 84 | } |
| 85 | |
| 86 | /* Return the vector of environment E. |
| 87 | This is used to get something to pass to execve. */ |
| 88 | |
| 89 | char ** |
| 90 | environ_vector (struct gdb_environ *e) |
| 91 | { |
| 92 | return e->vector; |
| 93 | } |
| 94 | \f |
| 95 | /* Return the value in environment E of variable VAR. */ |
| 96 | |
| 97 | char * |
| 98 | get_in_environ (const struct gdb_environ *e, const char *var) |
| 99 | { |
| 100 | int len = strlen (var); |
| 101 | char **vector = e->vector; |
| 102 | char *s; |
| 103 | |
| 104 | for (; (s = *vector) != NULL; vector++) |
| 105 | if (strncmp (s, var, len) == 0 && s[len] == '=') |
| 106 | return &s[len + 1]; |
| 107 | |
| 108 | return 0; |
| 109 | } |
| 110 | |
| 111 | /* Store the value in E of VAR as VALUE. */ |
| 112 | |
| 113 | void |
| 114 | set_in_environ (struct gdb_environ *e, const char *var, const char *value) |
| 115 | { |
| 116 | int i; |
| 117 | int len = strlen (var); |
| 118 | char **vector = e->vector; |
| 119 | char *s; |
| 120 | |
| 121 | for (i = 0; (s = vector[i]) != NULL; i++) |
| 122 | if (strncmp (s, var, len) == 0 && s[len] == '=') |
| 123 | break; |
| 124 | |
| 125 | if (s == 0) |
| 126 | { |
| 127 | if (i == e->allocated) |
| 128 | { |
| 129 | e->allocated += 10; |
| 130 | vector = (char **) xrealloc ((char *) vector, |
| 131 | (e->allocated + 1) * sizeof (char *)); |
| 132 | e->vector = vector; |
| 133 | } |
| 134 | vector[i + 1] = 0; |
| 135 | } |
| 136 | else |
| 137 | xfree (s); |
| 138 | |
| 139 | s = (char *) xmalloc (len + strlen (value) + 2); |
| 140 | strcpy (s, var); |
| 141 | strcat (s, "="); |
| 142 | strcat (s, value); |
| 143 | vector[i] = s; |
| 144 | |
| 145 | /* This used to handle setting the PATH and GNUTARGET variables |
| 146 | specially. The latter has been replaced by "set gnutarget" |
| 147 | (which has worked since GDB 4.11). The former affects searching |
| 148 | the PATH to find SHELL, and searching the PATH to find the |
| 149 | argument of "symbol-file" or "exec-file". Maybe we should have |
| 150 | some kind of "set exec-path" for that. But in any event, having |
| 151 | "set env" affect anything besides the inferior is a bad idea. |
| 152 | What if we want to change the environment we pass to the program |
| 153 | without afecting GDB's behavior? */ |
| 154 | |
| 155 | return; |
| 156 | } |
| 157 | |
| 158 | /* Remove the setting for variable VAR from environment E. */ |
| 159 | |
| 160 | void |
| 161 | unset_in_environ (struct gdb_environ *e, const char *var) |
| 162 | { |
| 163 | int len = strlen (var); |
| 164 | char **vector = e->vector; |
| 165 | char *s; |
| 166 | |
| 167 | for (; (s = *vector) != NULL; vector++) |
| 168 | { |
| 169 | if (strncmp (s, var, len) == 0 && s[len] == '=') |
| 170 | { |
| 171 | xfree (s); |
| 172 | /* Walk through the vector, shuffling args down by one, including |
| 173 | the NULL terminator. Can't use memcpy() here since the regions |
| 174 | overlap, and memmove() might not be available. */ |
| 175 | while ((vector[0] = vector[1]) != NULL) |
| 176 | { |
| 177 | vector++; |
| 178 | } |
| 179 | break; |
| 180 | } |
| 181 | } |
| 182 | } |