cde/programs/dtksh/ksh93/src/lib/libast/misc/setenviron.c

   1 /*
   2  * CDE - Common Desktop Environment
   3  *
   4  * Copyright (c) 1993-2012, The Open Group. All rights reserved.
   5  *
   6  * These libraries and programs are free software; you can
   7  * redistribute them and/or modify them under the terms of the GNU
   8  * Lesser General Public License as published by the Free Software
   9  * Foundation; either version 2 of the License, or (at your option)
  10  * any later version.
  11  *
  12  * These libraries and programs are distributed in the hope that
  13  * they will be useful, but WITHOUT ANY WARRANTY; without even the
  14  * implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
  15  * PURPOSE. See the GNU Lesser General Public License for more
  16  * details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with these librararies and programs; if not, write
  20  * to the Free Software Foundation, Inc., 51 Franklin Street, Fifth
  21  * Floor, Boston, MA 02110-1301 USA
  22  */
  23 /* $XConsortium: setenviron.c /main/2 1996/05/08 19:45:15 drk $ */
  24 /***************************************************************
  25 *                                                              *
  26 *                      AT&T - PROPRIETARY                      *
  27 *                                                              *
  28 *         THIS IS PROPRIETARY SOURCE CODE LICENSED BY          *
  29 *                          AT&T CORP.                          *
  30 *                                                              *
  31 *                Copyright (c) 1995 AT&T Corp.                 *
  32 *                     All Rights Reserved                      *
  33 *                                                              *
  34 *           This software is licensed by AT&T Corp.            *
  35 *       under the terms and conditions of the license in       *
  36 *       http://www.research.att.com/orgs/ssr/book/reuse        *
  37 *                                                              *
  38 *               This software was created by the               *
  39 *           Software Engineering Research Department           *
  40 *                    AT&T Bell Laboratories                    *
  41 *                                                              *
  42 *               For further information contact                *
  43 *                     gsf@research.att.com                     *
  44 *                                                              *
  45 ***************************************************************/
  46
  47 /* : : generated by proto : : */
  48
  49 #if !defined(__PROTO__)
  50 #if defined(__STDC__) || defined(__cplusplus) || defined(_proto) || defined(c_plusplus)
  51 #if defined(__cplusplus)
  52 #define __MANGLE__      "C"
  53 #else
  54 #define __MANGLE__
  55 #endif
  56 #define __STDARG__
  57 #define __PROTO__(x)    x
  58 #define __OTORP__(x)
  59 #define __PARAM__(n,o)  n
  60 #if !defined(__STDC__) && !defined(__cplusplus)
  61 #if !defined(c_plusplus)
  62 #define const
  63 #endif
  64 #define signed
  65 #define void            int
  66 #define volatile
  67 #define __V_            char
  68 #else
  69 #define __V_            void
  70 #endif
  71 #else
  72 #define __PROTO__(x)    ()
  73 #define __OTORP__(x)    x
  74 #define __PARAM__(n,o)  o
  75 #define __MANGLE__
  76 #define __V_            char
  77 #define const
  78 #define signed
  79 #define void            int
  80 #define volatile
  81 #endif
  82 #if defined(__cplusplus) || defined(c_plusplus)
  83 #define __VARARG__      ...
  84 #else
  85 #define __VARARG__
  86 #endif
  87 #if defined(__STDARG__)
  88 #define __VA_START__(p,a)       va_start(p,a)
  89 #else
  90 #define __VA_START__(p,a)       va_start(p)
  91 #endif
  92 #endif
  93 #include <ast.h>
  94 #include <fs3d.h>
  95
  96 #define INCREMENT       16              /* environ increment            */
  97
  98 char*
  99 setenviron __PARAM__((const char* akey), (akey)) __OTORP__(const char* akey;){
 100         static char**   envv;           /* recorded environ             */
 101         static char**   next;           /* next free slot               */
 102         static char**   last;           /* last free slot (0)           */
 103         static char     ok[] = "";      /* delete/optimization ok return*/
 104
 105         char*           key = (char*)akey;
 106         register char** v = environ;
 107         register char** p = envv;
 108         register char*  s;
 109         register char*  t;
 110         int             n;
 111
 112         if (p && !v)
 113         {
 114                 next = p;
 115                 *++next = 0;
 116         }
 117         else if (p != v || !v)
 118         {
 119                 if (v)
 120                 {
 121                         while (*v++);
 122                         n = v - environ + INCREMENT;
 123                         v = environ;
 124                 }
 125                 else n = INCREMENT;
 126                 if (!p || (last - p + 1) < n)
 127                 {
 128                         if (!p && fs3d(FS3D_TEST))
 129                         {
 130                                 /*
 131                                  * kick 3d initialization
 132                                  */
 133
 134                                 close(open(".", 0));
 135                                 v = environ;
 136                         }
 137                         if (!(p = newof(p, char*, n, 0)))
 138                                 return(0);
 139                         last = p + n - 1;
 140                 }
 141                 envv = environ = p;
 142                 if (v && v[0] && v[0][0] == '_' && v[0][1] == '=') *p++ = *v++;
 143                 else *p++ = "_=";
 144                 if (!v) *p = 0;
 145                 else while (*p = *v++)
 146                         if (p[0][0] == '_' && p[0][1] == '=') envv[0] = *p;
 147                         else p++;
 148                 next = p;
 149                 p = envv;
 150         }
 151         else if (next == last)
 152         {
 153                 n = last - v + INCREMENT + 1;
 154                 if (!(p = newof(p, char*, n, 0)))
 155                         return(0);
 156                 last = p + n - 1;
 157                 next = last - INCREMENT;
 158                 envv = environ = p;
 159         }
 160         if (!key) return(ok);
 161         for (; s = *p; p++)
 162         {
 163                 t = key;
 164                 do
 165                 {
 166                         if (!*t || *t == '=')
 167                         {
 168                                 if (*s == '=')
 169                                 {
 170                                         if (!*t)
 171                                         {
 172                                                 v = p++;
 173                                                 while (*v++ = *p++);
 174                                                 next--;
 175                                                 return(ok);
 176                                         }
 177                                         *p = key;
 178                                         return((s = strchr(key, '=')) ? s + 1 : (char*)0);
 179                                 }
 180                                 break;
 181                         }
 182                 } while (*t++ == *s++);
 183         }
 184         if (!(s = strchr(key, '='))) return(ok);
 185         p = next;
 186         *++next = 0;
 187         *p = key;
 188         return(s + 1);
 189 }