1 /* environ.c -- library for manipulating environments for GNU. 2 3 Copyright (C) 1986-2013 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 #define min(a, b) ((a) < (b) ? (a) : (b)) 19 #define max(a, b) ((a) > (b) ? (a) : (b)) 20 21 #include "defs.h" 22 #include "environ.h" 23 #include "gdb_string.h" 24 25 26 /* Return a new environment object. */ 27 28 struct gdb_environ * 29 make_environ (void) 30 { 31 struct gdb_environ *e; 32 33 e = (struct gdb_environ *) xmalloc (sizeof (struct gdb_environ)); 34 35 e->allocated = 10; 36 e->vector = (char **) xmalloc ((e->allocated + 1) * sizeof (char *)); 37 e->vector[0] = 0; 38 return e; 39 } 40 41 /* Free an environment and all the strings in it. */ 42 43 void 44 free_environ (struct gdb_environ *e) 45 { 46 char **vector = e->vector; 47 48 while (*vector) 49 xfree (*vector++); 50 51 xfree (e->vector); 52 xfree (e); 53 } 54 55 /* Copy the environment given to this process into E. 56 Also copies all the strings in it, so we can be sure 57 that all strings in these environments are safe to free. */ 58 59 void 60 init_environ (struct gdb_environ *e) 61 { 62 extern char **environ; 63 int i; 64 65 if (environ == NULL) 66 return; 67 68 for (i = 0; environ[i]; i++) /*EMPTY */ ; 69 70 if (e->allocated < i) 71 { 72 e->allocated = max (i, e->allocated + 10); 73 e->vector = (char **) xrealloc ((char *) e->vector, 74 (e->allocated + 1) * sizeof (char *)); 75 } 76 77 memcpy (e->vector, environ, (i + 1) * sizeof (char *)); 78 79 while (--i >= 0) 80 { 81 int len = strlen (e->vector[i]); 82 char *new = (char *) xmalloc (len + 1); 83 84 memcpy (new, e->vector[i], len + 1); 85 e->vector[i] = new; 86 } 87 } 88 89 /* Return the vector of environment E. 90 This is used to get something to pass to execve. */ 91 92 char ** 93 environ_vector (struct gdb_environ *e) 94 { 95 return e->vector; 96 } 97 98 /* Return the value in environment E of variable VAR. */ 99 100 char * 101 get_in_environ (const struct gdb_environ *e, const char *var) 102 { 103 int len = strlen (var); 104 char **vector = e->vector; 105 char *s; 106 107 for (; (s = *vector) != NULL; vector++) 108 if (strncmp (s, var, len) == 0 && s[len] == '=') 109 return &s[len + 1]; 110 111 return 0; 112 } 113 114 /* Store the value in E of VAR as VALUE. */ 115 116 void 117 set_in_environ (struct gdb_environ *e, const char *var, const char *value) 118 { 119 int i; 120 int len = strlen (var); 121 char **vector = e->vector; 122 char *s; 123 124 for (i = 0; (s = vector[i]) != NULL; i++) 125 if (strncmp (s, var, len) == 0 && s[len] == '=') 126 break; 127 128 if (s == 0) 129 { 130 if (i == e->allocated) 131 { 132 e->allocated += 10; 133 vector = (char **) xrealloc ((char *) vector, 134 (e->allocated + 1) * sizeof (char *)); 135 e->vector = vector; 136 } 137 vector[i + 1] = 0; 138 } 139 else 140 xfree (s); 141 142 s = (char *) xmalloc (len + strlen (value) + 2); 143 strcpy (s, var); 144 strcat (s, "="); 145 strcat (s, value); 146 vector[i] = s; 147 148 /* This used to handle setting the PATH and GNUTARGET variables 149 specially. The latter has been replaced by "set gnutarget" 150 (which has worked since GDB 4.11). The former affects searching 151 the PATH to find SHELL, and searching the PATH to find the 152 argument of "symbol-file" or "exec-file". Maybe we should have 153 some kind of "set exec-path" for that. But in any event, having 154 "set env" affect anything besides the inferior is a bad idea. 155 What if we want to change the environment we pass to the program 156 without afecting GDB's behavior? */ 157 158 return; 159 } 160 161 /* Remove the setting for variable VAR from environment E. */ 162 163 void 164 unset_in_environ (struct gdb_environ *e, char *var) 165 { 166 int len = strlen (var); 167 char **vector = e->vector; 168 char *s; 169 170 for (; (s = *vector) != NULL; vector++) 171 { 172 if (strncmp (s, var, len) == 0 && s[len] == '=') 173 { 174 xfree (s); 175 /* Walk through the vector, shuffling args down by one, including 176 the NULL terminator. Can't use memcpy() here since the regions 177 overlap, and memmove() might not be available. */ 178 while ((vector[0] = vector[1]) != NULL) 179 { 180 vector++; 181 } 182 break; 183 } 184 } 185 } 186