lib/classpath.c

   1 /* Java CLASSPATH handling.
   2    Copyright (C) 2001-2003, 2006, 2009-2024 Free Software Foundation, Inc.
   3    Written by Bruno Haible <haible@clisp.cons.org>, 2001.
   4
   5    This program is free software: you can redistribute it and/or modify
   6    it under the terms of the GNU General Public License as published by
   7    the Free Software Foundation, either version 3 of the License, or
   8    (at your option) any later version.
   9
  10    This program is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13    GNU General Public License for more details.
  14
  15    You should have received a copy of the GNU General Public License
  16    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
  17
  18 /* If CLASSPATHVAR is defined, this file is being #included, and config.h is
  19    therefore already included.  */
  20 #if !defined CLASSPATHVAR
  21 # include <config.h>
  22 #endif
  23
  24 /* Specification.  */
  25 #include "classpath.h"
  26
  27 #include <stdio.h>
  28 #include <stdlib.h>
  29 #include <string.h>
  30
  31 #include "xsetenv.h"
  32 #include "xalloc.h"
  33
  34 /* Name of environment variable.  */
  35 #ifndef CLASSPATHVAR
  36 # define CLASSPATHVAR "CLASSPATH"
  37 #endif
  38
  39 /* Separator in PATH like lists of pathnames.  */
  40 #if (defined _WIN32 && !defined __CYGWIN__) || defined __EMX__ || defined __DJGPP__
  41   /* Native Windows, OS/2, DOS */
  42 # define PATH_SEPARATOR ';'
  43 #else
  44   /* Unix */
  45 # define PATH_SEPARATOR ':'
  46 #endif
  47
  48 /* Return the new CLASSPATH value.  The given classpaths are prepended to
  49    the current CLASSPATH value.   If use_minimal_classpath, the current
  50    CLASSPATH is ignored.  */
  51 char *
  52 new_classpath (const char * const *classpaths, unsigned int classpaths_count,
  53                bool use_minimal_classpath)
  54 {
  55   const char *old_classpath;
  56   unsigned int length;
  57   unsigned int i;
  58   char *result;
  59   char *p;
  60
  61   old_classpath = (use_minimal_classpath ? NULL : getenv (CLASSPATHVAR));
  62   if (old_classpath == NULL)
  63     old_classpath = "";
  64
  65   length = 0;
  66   for (i = 0; i < classpaths_count; i++)
  67     length += strlen (classpaths[i]) + 1;
  68   length += strlen (old_classpath);
  69   if (classpaths_count > 0 && old_classpath[0] == '\0')
  70     length--;
  71
  72   result = XNMALLOC (length + 1, char);
  73   p = result;
  74   for (i = 0; i < classpaths_count; i++)
  75     {
  76       memcpy (p, classpaths[i], strlen (classpaths[i]));
  77       p += strlen (classpaths[i]);
  78       *p++ = PATH_SEPARATOR;
  79     }
  80   if (old_classpath[0] != '\0')
  81     {
  82       memcpy (p, old_classpath, strlen (old_classpath));
  83       p += strlen (old_classpath);
  84     }
  85   else
  86     {
  87       if (classpaths_count > 0)
  88         p--;
  89     }
  90   *p = '\0';
  91
  92   return result;
  93 }
  94
  95 /* Set CLASSPATH and returns a safe copy of its old value.  */
  96 char *
  97 set_classpath (const char * const *classpaths, unsigned int classpaths_count,
  98                bool use_minimal_classpath, bool verbose)
  99 {
 100   const char *old_CLASSPATH = getenv (CLASSPATHVAR);
 101   char *result = (old_CLASSPATH != NULL ? xstrdup (old_CLASSPATH) : NULL);
 102   char *new_CLASSPATH =
 103     new_classpath (classpaths, classpaths_count, use_minimal_classpath);
 104
 105   if (verbose)
 106     printf (CLASSPATHVAR "=%s ", new_CLASSPATH);
 107
 108   xsetenv (CLASSPATHVAR, new_CLASSPATH, 1);
 109
 110   free (new_CLASSPATH);
 111
 112   return result;
 113 }
 114
 115 /* Restore CLASSPATH to its previous value.  */
 116 void
 117 reset_classpath (char *old_classpath)
 118 {
 119   if (old_classpath != NULL)
 120     {
 121       xsetenv (CLASSPATHVAR, old_classpath, 1);
 122       free (old_classpath);
 123     }
 124   else
 125     unsetenv (CLASSPATHVAR);
 126 }