1  /* Determine the Java version supported by javaexec.
       2     Copyright (C) 2006-2023 Free Software Foundation, Inc.
       3     Written by Bruno Haible <bruno@clisp.org>, 2006.
       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  #include <config.h>
      19  
      20  /* Specification.  */
      21  #include "javaversion.h"
      22  
      23  #include <errno.h>
      24  #include <stdio.h>
      25  #include <stdlib.h>
      26  
      27  #if ENABLE_RELOCATABLE
      28  # include "relocatable.h"
      29  #else
      30  # define relocate(pathname) (pathname)
      31  # define relocate2(pathname,allocatedp) (*(allocatedp) = NULL, (pathname))
      32  #endif
      33  
      34  #include "javaexec.h"
      35  #include "spawn-pipe.h"
      36  #include "wait-process.h"
      37  #include "error.h"
      38  #include "gettext.h"
      39  
      40  #define _(str) gettext (str)
      41  
      42  /* Get PKGDATADIR.  */
      43  #include "configmake.h"
      44  
      45  
      46  struct locals
      47  {
      48    /* OUT */
      49    char *line;
      50  };
      51  
      52  static bool
      53  execute_and_read_line (const char *progname,
      54                         const char *prog_path, const char * const *prog_argv,
      55                         void *private_data)
      56  {
      57    struct locals *l = (struct locals *) private_data;
      58    pid_t child;
      59    int fd[1];
      60    FILE *fp;
      61    char *line;
      62    size_t linesize;
      63    size_t linelen;
      64    int exitstatus;
      65  
      66    /* Open a pipe to the JVM.  */
      67    child = create_pipe_in (progname, prog_path, prog_argv, NULL,
      68                            DEV_NULL, false, true, false, fd);
      69  
      70    if (child == -1)
      71      return false;
      72  
      73    /* Retrieve its result.  */
      74    fp = fdopen (fd[0], "r");
      75    if (fp == NULL)
      76      {
      77        error (0, errno, _("fdopen() failed"));
      78        return false;
      79      }
      80  
      81    line = NULL; linesize = 0;
      82    linelen = getline (&line, &linesize, fp);
      83    if (linelen == (size_t)(-1))
      84      {
      85        error (0, 0, _("%s subprocess I/O error"), progname);
      86        return false;
      87      }
      88    if (linelen > 0 && line[linelen - 1] == '\n')
      89      line[linelen - 1] = '\0';
      90  
      91    fclose (fp);
      92  
      93    /* Remove zombie process from process list, and retrieve exit status.  */
      94    exitstatus =
      95      wait_subprocess (child, progname, true, false, true, false, NULL);
      96    if (exitstatus != 0)
      97      {
      98        free (line);
      99        return false;
     100      }
     101  
     102    l->line = line;
     103    return false;
     104  }
     105  
     106  char *
     107  javaexec_version (void)
     108  {
     109    const char *class_name = "javaversion";
     110    char *malloc_pkgdatadir;
     111    const char *pkgdatadir = relocate2 (PKGDATADIR, &malloc_pkgdatadir);
     112    const char *args[1];
     113    struct locals locals;
     114  
     115    args[0] = NULL;
     116    locals.line = NULL;
     117    execute_java_class (class_name, &pkgdatadir, 1, true, NULL, args,
     118                        false, false, execute_and_read_line, &locals);
     119  
     120    free (malloc_pkgdatadir);
     121    return locals.line;
     122  }