1 /* environ.c -- library for manipulating environments for GNU. 2 3 Copyright 1986, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 2000, 4 2003 Free Software Foundation, Inc. 5 6 This program is free software; you can redistribute it and/or modify 7 it under the terms of the GNU General Public License as published by 8 the Free Software Foundation; either version 2 of the License, or 9 (at your option) any later version. 10 11 This program is distributed in the hope that it will be useful, 12 but WITHOUT ANY WARRANTY; without even the implied warranty of 13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 GNU General Public License for more details. 15 16 You should have received a copy of the GNU General Public License 17 along with this program; if not, write to the Free Software 18 Foundation, Inc., 59 Temple Place - Suite 330, 19 Boston, MA 02111-1307, USA. */ 20 21 #define min(a, b) ((a) < (b) ? (a) : (b)) 22 #define max(a, b) ((a) > (b) ? (a) : (b)) 23 24 #include "defs.h" 25 #include "environ.h" 26 #include "gdb_string.h" 27 28 29 /* Return a new environment object. */ 30 31 struct environ * 32 make_environ (void) 33 { 34 struct environ *e; 35 36 e = (struct environ *) xmalloc (sizeof (struct environ)); 37 38 e->allocated = 10; 39 e->vector = (char **) xmalloc ((e->allocated + 1) * sizeof (char *)); 40 e->vector[0] = 0; 41 return e; 42 } 43 44 /* Free an environment and all the strings in it. */ 45 46 void 47 free_environ (struct environ *e) 48 { 49 char **vector = e->vector; 50 51 while (*vector) 52 xfree (*vector++); 53 54 xfree (e); 55 } 56 57 /* Copy the environment given to this process into E. 58 Also copies all the strings in it, so we can be sure 59 that all strings in these environments are safe to free. */ 60 61 void 62 init_environ (struct environ *e) 63 { 64 extern char **environ; 65 int i; 66 67 if (environ == NULL) 68 return; 69 70 for (i = 0; environ[i]; i++) /*EMPTY */ ; 71 72 if (e->allocated < i) 73 { 74 e->allocated = max (i, e->allocated + 10); 75 e->vector = (char **) xrealloc ((char *) e->vector, 76 (e->allocated + 1) * sizeof (char *)); 77 } 78 79 memcpy (e->vector, environ, (i + 1) * sizeof (char *)); 80 81 while (--i >= 0) 82 { 83 int len = strlen (e->vector[i]); 84 char *new = (char *) xmalloc (len + 1); 85 memcpy (new, e->vector[i], len + 1); 86 e->vector[i] = new; 87 } 88 } 89 90 /* Return the vector of environment E. 91 This is used to get something to pass to execve. */ 92 93 char ** 94 environ_vector (struct environ *e) 95 { 96 return e->vector; 97 } 98 99 /* Return the value in environment E of variable VAR. */ 100 101 char * 102 get_in_environ (const struct environ *e, const char *var) 103 { 104 int len = strlen (var); 105 char **vector = e->vector; 106 char *s; 107 108 for (; (s = *vector) != NULL; vector++) 109 if (strncmp (s, var, len) == 0 && s[len] == '=') 110 return &s[len + 1]; 111 112 return 0; 113 } 114 115 /* Store the value in E of VAR as VALUE. */ 116 117 void 118 set_in_environ (struct environ *e, const char *var, const char *value) 119 { 120 int i; 121 int len = strlen (var); 122 char **vector = e->vector; 123 char *s; 124 125 for (i = 0; (s = vector[i]) != NULL; i++) 126 if (strncmp (s, var, len) == 0 && s[len] == '=') 127 break; 128 129 if (s == 0) 130 { 131 if (i == e->allocated) 132 { 133 e->allocated += 10; 134 vector = (char **) xrealloc ((char *) vector, 135 (e->allocated + 1) * sizeof (char *)); 136 e->vector = vector; 137 } 138 vector[i + 1] = 0; 139 } 140 else 141 xfree (s); 142 143 s = (char *) xmalloc (len + strlen (value) + 2); 144 strcpy (s, var); 145 strcat (s, "="); 146 strcat (s, value); 147 vector[i] = s; 148 149 /* This used to handle setting the PATH and GNUTARGET variables 150 specially. The latter has been replaced by "set gnutarget" 151 (which has worked since GDB 4.11). The former affects searching 152 the PATH to find SHELL, and searching the PATH to find the 153 argument of "symbol-file" or "exec-file". Maybe we should have 154 some kind of "set exec-path" for that. But in any event, having 155 "set env" affect anything besides the inferior is a bad idea. 156 What if we want to change the environment we pass to the program 157 without afecting GDB's behavior? */ 158 159 return; 160 } 161 162 /* Remove the setting for variable VAR from environment E. */ 163 164 void 165 unset_in_environ (struct environ *e, char *var) 166 { 167 int len = strlen (var); 168 char **vector = e->vector; 169 char *s; 170 171 for (; (s = *vector) != NULL; vector++) 172 { 173 if (DEPRECATED_STREQN (s, var, len) && s[len] == '=') 174 { 175 xfree (s); 176 /* Walk through the vector, shuffling args down by one, including 177 the NULL terminator. Can't use memcpy() here since the regions 178 overlap, and memmove() might not be available. */ 179 while ((vector[0] = vector[1]) != NULL) 180 { 181 vector++; 182 } 183 break; 184 } 185 } 186 } 187