lib/javaversion.c

   1 /* Determine the Java version supported by javaexec.
   2    Copyright (C) 2006-2024 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
  65   /* Open a pipe to the JVM.  */
  66   child = create_pipe_in (progname, prog_path, prog_argv, NULL, NULL,
  67                           DEV_NULL, false, true, false, fd);
  68
  69   if (child == -1)
  70     return false;
  71
  72   /* Retrieve its result.  */
  73   fp = fdopen (fd[0], "r");
  74   if (fp == NULL)
  75     error (EXIT_FAILURE, errno, _("fdopen() failed"));
  76
  77   line = NULL; linesize = 0;
  78   linelen = getline (&line, &linesize, fp);
  79   if (linelen == (size_t)(-1))
  80     {
  81       error (0, 0, _("%s subprocess I/O error"), progname);
  82       fclose (fp);
  83       wait_subprocess (child, progname, true, false, true, false, NULL);
  84     }
  85   else
  86     {
  87       int exitstatus;
  88
  89       if (linelen > 0 && line[linelen - 1] == '\n')
  90         line[linelen - 1] = '\0';
  91
  92       fclose (fp);
  93
  94       /* Remove zombie process from process list, and retrieve exit status.  */
  95       exitstatus =
  96         wait_subprocess (child, progname, true, false, true, false, NULL);
  97       if (exitstatus == 0)
  98         {
  99           l->line = line;
 100           return false;
 101         }
 102     }
 103   free (line);
 104   return false;
 105 }
 106
 107 char *
 108 javaexec_version (void)
 109 {
 110   const char *class_name = "javaversion";
 111   char *malloc_pkgdatadir;
 112   const char *pkgdatadir = relocate2 (PKGDATADIR, &malloc_pkgdatadir);
 113   const char *args[1];
 114   struct locals locals;
 115
 116   args[0] = NULL;
 117   locals.line = NULL;
 118   execute_java_class (class_name, &pkgdatadir, 1, true, NULL, args,
 119                       false, false, execute_and_read_line, &locals);
 120
 121   free (malloc_pkgdatadir);
 122   return locals.line;
 123 }