1  /* Java CLASSPATH handling.
       2     Copyright (C) 2001-2003, 2006, 2009-2023 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  }