gdb/environ.c

   1 /* environ.c -- library for manipulating environments for GNU.
   2    Copyright (C) 1986 Free Software Foundation, Inc.
   3
   4                        NO WARRANTY
   5
   6   BECAUSE THIS PROGRAM IS LICENSED FREE OF CHARGE, WE PROVIDE ABSOLUTELY
   7 NO WARRANTY, TO THE EXTENT PERMITTED BY APPLICABLE STATE LAW.  EXCEPT
   8 WHEN OTHERWISE STATED IN WRITING, FREE SOFTWARE FOUNDATION, INC,
   9 RICHARD M. STALLMAN AND/OR OTHER PARTIES PROVIDE THIS PROGRAM "AS IS"
  10 WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING,
  11 BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
  12 FITNESS FOR A PARTICULAR PURPOSE.  THE ENTIRE RISK AS TO THE QUALITY
  13 AND PERFORMANCE OF THE PROGRAM IS WITH YOU.  SHOULD THE PROGRAM PROVE
  14 DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING, REPAIR OR
  15 CORRECTION.
  16
  17  IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW WILL RICHARD M.
  18 STALLMAN, THE FREE SOFTWARE FOUNDATION, INC., AND/OR ANY OTHER PARTY
  19 WHO MAY MODIFY AND REDISTRIBUTE THIS PROGRAM AS PERMITTED BELOW, BE
  20 LIABLE TO YOU FOR DAMAGES, INCLUDING ANY LOST PROFITS, LOST MONIES, OR
  21 OTHER SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE
  22 USE OR INABILITY TO USE (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR
  23 DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY THIRD PARTIES OR
  24 A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS) THIS
  25 PROGRAM, EVEN IF YOU HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH
  26 DAMAGES, OR FOR ANY CLAIM BY ANY OTHER PARTY.
  27
  28                 GENERAL PUBLIC LICENSE TO COPY
  29
  30   1. You may copy and distribute verbatim copies of this source file
  31 as you receive it, in any medium, provided that you conspicuously and
  32 appropriately publish on each copy a valid copyright notice "Copyright
  33 (C) 1986 Free Software Foundation, Inc."; and include following the
  34 copyright notice a verbatim copy of the above disclaimer of warranty
  35 and of this License.  You may charge a distribution fee for the
  36 physical act of transferring a copy.
  37
  38   2. You may modify your copy or copies of this source file or
  39 any portion of it, and copy and distribute such modifications under
  40 the terms of Paragraph 1 above, provided that you also do the following:
  41
  42     a) cause the modified files to carry prominent notices stating
  43     that you changed the files and the date of any change; and
  44
  45     b) cause the whole of any work that you distribute or publish,
  46     that in whole or in part contains or is a derivative of this
  47     program or any part thereof, to be licensed at no charge to all
  48     third parties on terms identical to those contained in this
  49     License Agreement (except that you may choose to grant more extensive
  50     warranty protection to some or all third parties, at your option).
  51
  52     c) You may charge a distribution fee for the physical act of
  53     transferring a copy, and you may at your option offer warranty
  54     protection in exchange for a fee.
  55
  56 Mere aggregation of another unrelated program with this program (or its
  57 derivative) on a volume of a storage or distribution medium does not bring
  58 the other program under the scope of these terms.
  59
  60   3. You may copy and distribute this program (or a portion or derivative
  61 of it, under Paragraph 2) in object code or executable form under the terms
  62 of Paragraphs 1 and 2 above provided that you also do one of the following:
  63
  64     a) accompany it with the complete corresponding machine-readable
  65     source code, which must be distributed under the terms of
  66     Paragraphs 1 and 2 above; or,
  67
  68     b) accompany it with a written offer, valid for at least three
  69     years, to give any third party free (except for a nominal
  70     shipping charge) a complete machine-readable copy of the
  71     corresponding source code, to be distributed under the terms of
  72     Paragraphs 1 and 2 above; or,
  73
  74     c) accompany it with the information you received as to where the
  75     corresponding source code may be obtained.  (This alternative is
  76     allowed only for noncommercial distribution and only if you
  77     received the program in object code or executable form alone.)
  78
  79 For an executable file, complete source code means all the source code for
  80 all modules it contains; but, as a special exception, it need not include
  81 source code for modules which are standard libraries that accompany the
  82 operating system on which the executable file runs.
  83
  84   4. You may not copy, sublicense, distribute or transfer this program
  85 except as expressly provided under this License Agreement.  Any attempt
  86 otherwise to copy, sublicense, distribute or transfer this program is void and
  87 your rights to use the program under this License agreement shall be
  88 automatically terminated.  However, parties who have received computer
  89 software programs from you with this License Agreement will not have
  90 their licenses terminated so long as such parties remain in full compliance.
  91
  92   5. If you wish to incorporate parts of this program into other free
  93 programs whose distribution conditions are different, write to the Free
  94 Software Foundation at 675 Mass Ave, Cambridge, MA 02139.  We have not yet
  95 worked out a simple rule that can be stated here, but we will often permit
  96 this.  We will be guided by the two goals of preserving the free status of
  97 all derivatives of our free software and of promoting the sharing and reuse of
  98 software.
  99
 100 In other words, feel free to share this program, but don't try to
 101 stop anyone else from sharing it.  */
 102
 103 #define min(a, b) ((a) < (b) ? (a) : (b))
 104 #define max(a, b) ((a) > (b) ? (a) : (b))
 105
 106 #include "environ.h"
 107 \f
 108 /* Return a new environment object.  */
 109
 110 struct environ *
 111 make_environ ()
 112 {
 113   register struct environ *e;
 114
 115   e = (struct environ *) xmalloc (sizeof (struct environ));
 116
 117   e->allocated = 10;
 118   e->vector = (char **) xmalloc ((e->allocated + 1) * sizeof (char *));
 119   e->vector[0] = 0;
 120   return e;
 121 }
 122
 123 /* Free an environment and all the strings in it.  */
 124
 125 void
 126 free_environ (e)
 127      register struct environ *e;
 128 {
 129   register char **vector = e->vector;
 130
 131   while (*vector)
 132     free (*vector++);
 133
 134   free (e);
 135 }
 136
 137 /* Copy the environment given to this process into E.
 138    Also copies all the strings in it, so we can be sure
 139    that all strings in these environments are safe to free.  */
 140
 141 void
 142 init_environ (e)
 143      register struct environ *e;
 144 {
 145   extern char **environ;
 146   register int i;
 147
 148   for (i = 0; environ[i]; i++);
 149
 150   if (e->allocated < i)
 151     {
 152       e->allocated = max (i, e->allocated + 10);
 153       e->vector = (char **) xrealloc (e->vector,
 154                                       (e->allocated + 1) * sizeof (char *));
 155     }
 156
 157   bcopy (environ, e->vector, (i + 1) * sizeof (char *));
 158
 159   while (--i >= 0)
 160     {
 161       register int len = strlen (e->vector[i]);
 162       register char *new = (char *) xmalloc (len + 1);
 163       bcopy (e->vector[i], new, len);
 164       e->vector[i] = new;
 165     }
 166 }
 167
 168 /* Return the vector of environment E.
 169    This is used to get something to pass to execve.  */
 170
 171 char **
 172 environ_vector (e)
 173      struct environ *e;
 174 {
 175   return e->vector;
 176 }
 177 \f
 178 /* Return the value in environment E of variable VAR.  */
 179
 180 char *
 181 get_in_environ (e, var)
 182      struct environ *e;
 183      char *var;
 184 {
 185   register int len = strlen (var);
 186   register char **vector = e->vector;
 187   register char *s;
 188
 189   for (; s = *vector; vector++)
 190     if (!strncmp (s, var, len)
 191         && s[len] == '=')
 192       return &s[len + 1];
 193
 194   return 0;
 195 }
 196
 197 /* Store the value in E of VAR as VALUE.  */
 198
 199 void
 200 set_in_environ (e, var, value)
 201      struct environ *e;
 202      char *var;
 203      char *value;
 204 {
 205   register int i;
 206   register int len = strlen (var);
 207   register char **vector = e->vector;
 208   register char *s;
 209
 210   for (i = 0; s = vector[i]; i++)
 211     if (!strncmp (s, var, len)
 212         && s[len] == '=')
 213       break;
 214
 215   if (s == 0)
 216     {
 217       if (i == e->allocated)
 218         {
 219           e->allocated += 10;
 220           vector = (char **) xrealloc (vector,
 221                                        (e->allocated + 1) * sizeof (char *));
 222           e->vector = vector;
 223         }
 224       vector[i + 1] = 0;
 225     }
 226   else
 227     free (s);
 228
 229   s = (char *) xmalloc (len + strlen (value) + 2);
 230   strcpy (s, var);
 231   strcat (s, "=");
 232   strcat (s, value);
 233   vector[i] = s;
 234   return;
 235 }
 236
 237 /* Remove the setting for variable VAR from environment E.  */
 238
 239 void
 240 unset_in_environ (e, var)
 241      struct environ *e;
 242      char *var;
 243 {
 244   register int len = strlen (var);
 245   register char **vector = e->vector;
 246   register char *s;
 247
 248   for (; s = *vector; vector++)
 249     if (!strncmp (s, var, len)
 250         && s[len] == '=')
 251       {
 252         free (s);
 253         bcopy (vector + 1, vector,
 254                (e->allocated - (vector - e->vector)) * sizeof (char *));
 255         e->vector[e->allocated - 1] = 0;
 256         return;
 257       }
 258 }