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   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 }