lib/classpath.c

   1 /* Java CLASSPATH handling.
   2    Copyright (C) 2001-2003, 2006, 2009-2017 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 <http://www.gnu.org/licenses/>.  */
  17
  18 #include <config.h>
  19
  20 /* Specification.  */
  21 #include "classpath.h"
  22
  23 #include <stdio.h>
  24 #include <stdlib.h>
  25 #include <string.h>
  26
  27 #include "xsetenv.h"
  28 #include "xalloc.h"
  29
  30 /* Name of environment variable.  */
  31 #ifndef CLASSPATHVAR
  32 # define CLASSPATHVAR "CLASSPATH"
  33 #endif
  34
  35 /* Separator in PATH like lists of pathnames.  */
  36 #if ((defined _WIN32 || defined __WIN32__) && !defined __CYGWIN__) || defined __EMX__ || defined __DJGPP__
  37   /* Native Windows, OS/2, DOS */
  38 # define PATH_SEPARATOR ';'
  39 #else
  40   /* Unix */
  41 # define PATH_SEPARATOR ':'
  42 #endif
  43
  44 /* Return the new CLASSPATH value.  The given classpaths are prepended to
  45    the current CLASSPATH value.   If use_minimal_classpath, the current
  46    CLASSPATH is ignored.  */
  47 char *
  48 new_classpath (const char * const *classpaths, unsigned int classpaths_count,
  49                bool use_minimal_classpath)
  50 {
  51   const char *old_classpath;
  52   unsigned int length;
  53   unsigned int i;
  54   char *result;
  55   char *p;
  56
  57   old_classpath = (use_minimal_classpath ? NULL : getenv (CLASSPATHVAR));
  58   if (old_classpath == NULL)
  59     old_classpath = "";
  60
  61   length = 0;
  62   for (i = 0; i < classpaths_count; i++)
  63     length += strlen (classpaths[i]) + 1;
  64   length += strlen (old_classpath);
  65   if (classpaths_count > 0 && old_classpath[0] == '\0')
  66     length--;
  67
  68   result = XNMALLOC (length + 1, char);
  69   p = result;
  70   for (i = 0; i < classpaths_count; i++)
  71     {
  72       memcpy (p, classpaths[i], strlen (classpaths[i]));
  73       p += strlen (classpaths[i]);
  74       *p++ = PATH_SEPARATOR;
  75     }
  76   if (old_classpath[0] != '\0')
  77     {
  78       memcpy (p, old_classpath, strlen (old_classpath));
  79       p += strlen (old_classpath);
  80     }
  81   else
  82     {
  83       if (classpaths_count > 0)
  84         p--;
  85     }
  86   *p = '\0';
  87
  88   return result;
  89 }
  90
  91 /* Set CLASSPATH and returns a safe copy of its old value.  */
  92 char *
  93 set_classpath (const char * const *classpaths, unsigned int classpaths_count,
  94                bool use_minimal_classpath, bool verbose)
  95 {
  96   const char *old_CLASSPATH = getenv (CLASSPATHVAR);
  97   char *result = (old_CLASSPATH != NULL ? xstrdup (old_CLASSPATH) : NULL);
  98   char *new_CLASSPATH =
  99     new_classpath (classpaths, classpaths_count, use_minimal_classpath);
 100
 101   if (verbose)
 102     printf (CLASSPATHVAR "=%s ", new_CLASSPATH);
 103
 104   xsetenv (CLASSPATHVAR, new_CLASSPATH, 1);
 105
 106   free (new_CLASSPATH);
 107
 108   return result;
 109 }
 110
 111 /* Restore CLASSPATH to its previous value.  */
 112 void
 113 reset_classpath (char *old_classpath)
 114 {
 115   if (old_classpath != NULL)
 116     {
 117       xsetenv (CLASSPATHVAR, old_classpath, 1);
 118       free (old_classpath);
 119     }
 120   else
 121     unsetenv (CLASSPATHVAR);
 122 }