contrib/opie/libmissing/env.c

   1 /* env.c: Replacement environment handling functions.
   2
   3 %%% portions-copyright-cmetz
   4 Portions of this software are Copyright 1996 by Craig Metz, All Rights
   5 Reserved. The Inner Net License Version 2 applies to these portions of
   6 the software.
   7 You should have received a copy of the license with this software. If
   8 you didn't get a copy, you may request one from <license@inner.net>.
   9
  10 Portions of this software are Copyright 1995 by Randall Atkinson and Dan
  11 McDonald, All Rights Reserved. All Rights under this copyright are assigned
  12 to the U.S. Naval Research Laboratory (NRL). The NRL Copyright Notice and
  13 License Agreement applies to this software.
  14
  15         History:
  16
  17         Modified by cmetz for OPIE 2.2. Changed ifdefs for libmissing.
  18              Combined all env functions and made _findenv static.
  19              Including headers is a good idea, though. Add more headers.
  20         Modified at NRL for OPIE 2.0.
  21         Originally from BSD.
  22 */
  23 /*
  24  * Copyright (c) 1987 Regents of the University of California.
  25  * All rights reserved.
  26  *
  27  * Redistribution and use in source and binary forms are permitted
  28  * provided that the above copyright notice and this paragraph are
  29  * duplicated in all such forms and that any documentation,
  30  * advertising materials, and other materials related to such
  31  * distribution and use acknowledge that the software was developed
  32  * by the University of California, Berkeley.  The name of the
  33  * University may not be used to endorse or promote products derived
  34  * from this software without specific prior written permission.
  35  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
  36  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
  37  * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  38  */
  39
  40 #include "opie_cfg.h"
  41 #include <stdio.h>
  42 #if HAVE_UNISTD_H
  43 #include <unistd.h>
  44 #endif /* HAVE_UNISTD_H */
  45 #if HAVE_STDLIB_H
  46 #include <stdlib.h>
  47 #endif /* HAVE_STDLIB_H */
  48 #include "opie.h"
  49
  50 static char *_findenv FUNCTION((name, offset), register char *name AND int *offset)
  51 {
  52   extern char **environ;
  53   register int len;
  54   register char **P, *C;
  55
  56   for (C = name, len = 0; *C && *C != '='; ++C, ++len);
  57   for (P = environ; *P; ++P)
  58     if (!strncmp(*P, name, len))
  59       if (*(C = *P + len) == '=') {
  60         *offset = P - environ;
  61         return (++C);
  62       }
  63   return (NULL);
  64 }
  65
  66 #if !HAVE_GETENV
  67 char *getenv FUNCTION((name), char *name)
  68 {
  69   int offset;
  70   char *_findenv();
  71
  72   return (_findenv(name, &offset));
  73 }
  74 #endif /* !HAVE_GETENV */
  75
  76 #if !HAVE_SETENV
  77 int setenv FUNCTION((name, value, rewrite), char *name AND char *value AND int rewrite)
  78 {
  79   extern char **environ;
  80   static int alloced;   /* if allocated space before */
  81   register char *C;
  82   int l_value, offset;
  83
  84   if (*value == '=')    /* no `=' in value */
  85     ++value;
  86   l_value = strlen(value);
  87   if ((C = _findenv(name, &offset))) {  /* find if already exists */
  88     if (!rewrite)
  89       return (0);
  90     if (strlen(C) >= l_value) { /* old larger; copy over */
  91       while (*C++ = *value++);
  92       return (0);
  93     }
  94   } else {      /* create new slot */
  95     register int cnt;
  96     register char **P;
  97
  98     for (P = environ, cnt = 0; *P; ++P, ++cnt);
  99     if (alloced) {      /* just increase size */
 100       environ = (char **) realloc((char *) environ,
 101                                   (u_int) (sizeof(char *) * (cnt + 2)));
 102
 103       if (!environ)
 104         return (-1);
 105     } else {    /* get new space */
 106       alloced = 1;      /* copy old entries into it */
 107       P = (char **) malloc((u_int) (sizeof(char *) *
 108                                     (cnt + 2)));
 109
 110       if (!P)
 111         return (-1);
 112       strncpy(P, environ, cnt * sizeof(char *));
 113
 114       environ = P;
 115     }
 116     environ[cnt + 1] = NULL;
 117     offset = cnt;
 118   }
 119   for (C = name; *C && *C != '='; ++C); /* no `=' in name */
 120   if (!(environ[offset] =       /* name + `=' + value */
 121         malloc((u_int) ((int) (C - name) + l_value + 2))))
 122     return (-1);
 123   for (C = environ[offset]; (*C = *name++) && *C != '='; ++C);
 124   for (*C++ = '='; *C++ = *value++;);
 125   return (0);
 126 }
 127 #endif /* !HAVE_SETENV */
 128
 129 #if !HAVE_UNSETENV
 130 VOIDRET unsetenv FUNCTION((name), char *name)
 131 {
 132   extern char **environ;
 133   register char **P;
 134   int offset;
 135
 136   while (_findenv(name, &offset))       /* if set multiple times */
 137     for (P = &environ[offset];; ++P)
 138       if (!(*P = *(P + 1)))
 139         break;
 140 }
 141 #endif /* !HAVE_UNSETENV */