src/java.base/windows/native/libjava/ProcessEnvironment_md.c

/*
 * Copyright (c) 2003, 2025, 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
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 */
#include <stdlib.h>

#include "jni.h"
#include "jni_util.h"
#include <windows.h>

/* Returns a Windows style environment block, discarding final trailing NUL */
JNIEXPORT jstring JNICALL
Java_java_lang_ProcessEnvironment_environmentBlock(JNIEnv *env, jclass klass)
{
    int i;
    jstring envblock;
    jchar *blockW = (jchar *) GetEnvironmentStringsW();
    if (blockW == NULL) {
        /* Out of memory is our best guess. */
        JNU_ThrowOutOfMemoryError(env, "GetEnvironmentStrings failed");
        return NULL;
    }

    /* Don't search for "\u0000\u0000", since an empty environment
       block may legitimately consist of a single "\u0000".  */
    for (i = 0; blockW[i];)
        while (blockW[i++])
            ;

    envblock = (*env)->NewString(env, blockW, i);
    FreeEnvironmentStringsW(blockW);
    return envblock;
}