gcc/m2/gm2-libs/SEnvironment.mod

   1 (* SEnvironment.mod provides access to the environment of a process.
   2
   3 Copyright (C) 2001-2024 Free Software Foundation, Inc.
   4 Contributed by Gaius Mulley <gaius.mulley@southwales.ac.uk>.
   5
   6 This file is part of GNU Modula-2.
   7
   8 GNU Modula-2 is free software; you can redistribute it and/or modify
   9 it under the terms of the GNU General Public License as published by
  10 the Free Software Foundation; either version 3, or (at your option)
  11 any later version.
  12
  13 GNU Modula-2 is distributed in the hope that it will be useful, but
  14 WITHOUT ANY WARRANTY; without even the implied warranty of
  15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16 General Public License for more details.
  17
  18 Under Section 7 of GPL version 3, you are granted additional
  19 permissions described in the GCC Runtime Library Exception, version
  20 3.1, as published by the Free Software Foundation.
  21
  22 You should have received a copy of the GNU General Public License and
  23 a copy of the GCC Runtime Library Exception along with this program;
  24 see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  25 <http://www.gnu.org/licenses/>.  *)
  26
  27 IMPLEMENTATION MODULE SEnvironment ;
  28
  29 FROM DynamicStrings IMPORT string, InitStringCharStar,
  30                            InitStringDB, InitStringCharStarDB,
  31                            InitStringCharDB, MultDB, DupDB, SliceDB ;
  32
  33 FROM libc IMPORT getenv, putenv ;
  34
  35 (*
  36 #undef GM2_DEBUG_SENVIRONMENT
  37 if defined(GM2_DEBUG_SENVIRONMENT)
  38 #  define InitString(X) InitStringDB(X, __FILE__, __LINE__)
  39 #  define InitStringCharStar(X) InitStringCharStarDB(X, __FILE__, __LINE__)
  40 #  define InitStringChar(X) InitStringCharDB(X, __FILE__, __LINE__)
  41 #  define Mult(X,Y) MultDB(X, Y, __FILE__, __LINE__)
  42 #  define Dup(X) DupDB(X, __FILE__, __LINE__)
  43 #  define Slice(X,Y,Z) SliceDB(X, Y, Z, __FILE__, __LINE__)
  44 #endif
  45 *)
  46
  47
  48 (*
  49    GetEnvironment - gets the environment variable Env and places
  50                     a copy of its value into String, dest.
  51                     It returns TRUE if the string Env was found in
  52                     the processes environment.
  53 *)
  54
  55 PROCEDURE GetEnvironment (Env: String;
  56                           VAR dest: String) : BOOLEAN ;
  57 VAR
  58    Addr: POINTER TO CHAR ;
  59 BEGIN
  60    IF Env=NIL
  61    THEN
  62       dest := NIL ;
  63       RETURN FALSE
  64    ELSE
  65       Addr := getenv (string (Env)) ;
  66       IF Addr=NIL
  67       THEN
  68          dest := NIL ;
  69          RETURN FALSE
  70       ELSE
  71          dest := InitStringCharStar (Addr) ;
  72          RETURN TRUE
  73       END
  74    END
  75 END GetEnvironment ;
  76
  77
  78 (*
  79    PutEnvironment - change or add an environment variable definition EnvDef.
  80                     TRUE is returned if the environment variable was
  81                     set or changed successfully.
  82 *)
  83
  84 PROCEDURE PutEnvironment (EnvDef: String) : BOOLEAN ;
  85 BEGIN
  86    RETURN putenv (string (EnvDef)) = 0
  87 END PutEnvironment ;
  88
  89
  90 END SEnvironment.