--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/macosx/bin/jexec.c	Tue Mar 06 20:34:38 2012 +0000
@@ -0,0 +1,239 @@
+/*
+ * Copyright (c) 1999, 2012, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * jexec for J2SE
+ *
+ * jexec is used by the system to allow execution of JAR files.
+ *    Essentially jexec needs to run java and
+ *    needs to be a native ISA executable (not a shell script), although
+ *    this native ISA executable requirement was a mistake that will be fixed.
+ *    (<ISA> is sparc or i386 or amd64).
+ *
+ *    When you execute a jar file, jexec is executed by the system as follows:
+ *      /usr/java/jre/lib/<ISA>/jexec -jar JARFILENAME
+ *    so this just needs to be turned into:
+ *      /usr/java/jre/bin/java -jar JARFILENAME
+ *
+ * Solaris systems (new 7's and all 8's) will be looking for jexec at:
+ *      /usr/java/jre/lib/<ISA>/jexec
+ * Older systems may need to add this to their /etc/system file:
+ *      set javaexec:jexec="/usr/java/jre/lib/<ISA>/jexec"
+ *     and reboot the machine for this to work.
+ *
+ * This source should be compiled as:
+ *      cc -o jexec jexec.c
+ *
+ * And jexec should be placed at the following location of the installation:
+ *      <INSTALLATIONDIR>/jre/lib/<ISA>/jexec  (for Solaris)
+ *      <INSTALLATIONDIR>/lib/jexec            (for Linux)
+ *
+ * NOTE: Unless <INSTALLATIONDIR> is the "default" JDK on the system
+ *       (i.e. /usr/java -> <INSTALLATIONDIR>), this jexec will not be
+ *       found.  The 1.2 java is only the default on Solaris 8 and
+ *       on systems where the 1.2 packages were installed and no 1.1
+ *       java was found.
+ *
+ * NOTE: You must use 1.2 jar to build your jar files. The system
+ *       doesn't seem to pick up 1.1 jar files.
+ *
+ * NOTE: We don't need to set LD_LIBRARY_PATH here, even though we
+ *       are running the actual java binary because the java binary will
+ *       look for it's libraries through it's own runpath, which uses
+ *       $ORIGIN.
+ *
+ * NOTE: This jexec should NOT have any special .so library needs because
+ *       it appears that this executable will NOT get the $ORIGIN of jexec
+ *       but the $ORIGIN of the jar file being executed. Be careful to keep
+ *       this program simple and with no .so dependencies.
+ */
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <string.h>
+#include <limits.h>
+#include <errno.h>
+
+static const int CRAZY_EXEC = ENOEXEC;
+static const int BAD_MAGIC  = ENOEXEC;
+
+static const char * BAD_EXEC_MSG     = "jexec failed";
+static const char * CRAZY_EXEC_MSG   = "missing args";
+static const char * MISSING_JAVA_MSG = "can't locate java";
+static const char * UNKNOWN_ERROR    = "unknown error";
+
+/* Define a constant that represents the number of directories to pop off the
+ * current location to find the java binary */
+static const int RELATIVE_DEPTH = 3;
+
+/* path to java after popping */
+static const char * BIN_PATH = "/bin/java";
+
+/* flag used when running JAR files */
+static const char * JAR_FLAG = "-jar";
+
+int main(int argc, const char * argv[]);
+void errorExit(int error, const char * message);
+int getJavaPath(const char * path, char * buf, int depth);
+
+/*
+ * This is the main entry point.  This program (jexec) will attempt to execute
+ * a JAR file by finding the Java program (java), relative to its own location.
+ * The exact location of the Java program depends on the platform, i.e.
+ *
+ *      <INSTALLATIONDIR>/jre/lib/<ISA>/jexec  (for Solaris)
+ *      <INSTALLATIONDIR>/lib/jexec            (for Linux JDK)
+ *
+ * Once the Java program is found, this program copies any remaining arguments
+ * into another array, which is then used to exec the Java program.
+ *
+ * On Linux this program does some additional steps.  When copying the array of
+ * args, it is necessary to insert the "-jar" flag between arg[0], the program
+ * name, and the original arg[1], which is presumed to be a path to a JAR file.
+ * It is also necessary to verify that the original arg[1] really is a JAR file.
+ * (These steps are unnecessary on Solaris because they are taken care of by
+ * the kernel.)
+ */
+int main(int argc, const char * argv[]) {
+    /* We need to exec the original arguments using java, instead of jexec.
+     * Also, for Linux, it is necessary to add the "-jar" argument between
+     * the new arg[0], and the old arg[1].  To do this we will create a new
+     * args array. */
+    char          java[PATH_MAX + 1];    /* path to java binary  */
+    const char ** nargv = NULL;          /* new args array       */
+    int           nargc = 0;             /* new args array count */
+    int           argi  = 0;             /* index into old array */
+
+    /* Make sure we have something to work with */
+    if ((argc < 1) || (argv == NULL)) {
+        /* Shouldn't happen... */
+        errorExit(CRAZY_EXEC, CRAZY_EXEC_MSG);
+    }
+
+    /* Get the path to the java binary, which is in a known position relative
+     * to our current position, which is in argv[0]. */
+    if (getJavaPath(argv[argi++], java, RELATIVE_DEPTH) != 0) {
+        errorExit(errno, MISSING_JAVA_MSG);
+    }
+
+    nargv = (const char **) malloc((argc + 2) * (sizeof (const char *)));
+    nargv[nargc++] = java;
+
+    if (argc >= 2) {
+        const char * jarfile = argv[argi++];
+        const char * message = NULL;
+
+        /* the next argument is the path to the JAR file */
+        nargv[nargc++] = jarfile;
+    }
+
+    /* finally copy any remaining arguments */
+    while (argi < argc) {
+        nargv[nargc++] = argv[argi++];
+    }
+
+    /* finally add one last terminating null */
+    nargv[nargc++] = NULL;
+
+    /* It's time to exec the java binary with the new arguments.  It
+     * is possible that we've reached this point without actually
+     * having a JAR file argument (i.e. if argc < 2), but we still
+     * want to exec the java binary, since that will take care of
+     * displaying the correct usage. */
+    execv(java, (char * const *) nargv);
+
+    /* If the exec worked, this process would have been replaced
+     * by the new process.  So any code reached beyond this point
+     * implies an error in the exec. */
+    free(nargv);
+    errorExit(errno, BAD_EXEC_MSG);
+    return 0; // keep the compiler happy
+}
+
+
+/*
+ * Exit the application by setting errno, and writing a message.
+ *
+ * Parameters:
+ *     error   - errno is set to this value, and it is used to exit.
+ *     message - the message to write.
+ */
+void errorExit(int error, const char * message) {
+    if (error != 0) {
+        errno = error;
+        perror((message != NULL) ? message : UNKNOWN_ERROR);
+    }
+
+    exit((error == 0) ? 0 : 1);
+}
+
+
+/*
+ * Get the path to the java binary that should be relative to the current path.
+ *
+ * Parameters:
+ *     path  - the input path that the java binary that should be relative to.
+ *     buf   - a buffer of size PATH_MAX or greater that the java path is
+ *             copied to.
+ *     depth - the number of names to trim off the current path, including the
+ *             name of this program.
+ *
+ * Returns:
+ *     This function returns 0 on success; otherwise it returns the value of
+ *     errno.
+ */
+int getJavaPath(const char * path, char * buf, int depth) {
+    int result = 0;
+
+    /* Get the full path to this program.  Depending on whether this is Solaris
+     * or Linux, this will be something like,
+     *
+     *     <FOO>/jre/lib/<ISA>/jexec  (for Solaris)
+     *     <FOO>/lib/jexec            (for Linux)
+     */
+    if (realpath(path, buf) != NULL) {
+        int count = 0;
+
+        /* Pop off the filename, and then subdirectories for each level of
+         * depth */
+        for (count = 0; count < depth; count++) {
+            *(strrchr(buf, '/')) = '\0';
+        }
+
+        /* Append the relative location of java, creating something like,
+         *
+         *     <FOO>/jre/bin/java  (for Solaris)
+         *     <FOO>/bin/java      (for Linux)
+         */
+        strcat(buf, BIN_PATH);
+    }
+    else {
+        /* Failed to get the path */
+        result = errno;
+    }
+
+    return (result);
+}