1 files changed, 141 insertions, 0 deletions
diff --git a/src/bldprogs/VBoxCmp.cpp b/src/bldprogs/VBoxCmp.cpp
new file mode 100644
index 00000000..c4f08950
--- /dev/null
+++ b/src/bldprogs/VBoxCmp.cpp
@@ -0,0 +1,141 @@
+/* $Id: VBoxCmp.cpp $ */
+/** @file
+ * File Compare - Compares two files byte by byte.
+ */
+
+/*
+ * Copyright (C) 2006-2023 Oracle and/or its affiliates.
+ *
+ * This file is part of VirtualBox base platform packages, as
+ * available from https://www.virtualbox.org.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation, in version 3 of the
+ * License.
+ *
+ * This program 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 for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <https://www.gnu.org/licenses>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-only
+ */
+
+
+/*********************************************************************************************************************************
+*   Header Files                                                                                                                 *
+*********************************************************************************************************************************/
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <errno.h>
+
+#include <iprt/string.h>
+#include <iprt/stdarg.h>
+
+
+/**
+ * Writes an error message.
+ *
+ * @returns RTEXITCODE_FAILURE.
+ * @param   pcszFormat          Error message.
+ * @param   ...                 Format argument referenced in the message.
+ */
+static RTEXITCODE printErr(const char *pcszFormat, ...)
+{
+    va_list va;
+
+    fprintf(stderr, "VBoxCmp: ");
+    va_start(va, pcszFormat);
+    vfprintf(stderr, pcszFormat, va);
+    va_end(va);
+
+    return RTEXITCODE_FAILURE;
+}
+
+
+static FILE *openFile(const char *pszFile)
+{
+#if defined(RT_OS_WINDOWS) || defined(RT_OS_OS2)
+    FILE *pFile = fopen(pszFile, "rb");
+#else
+    FILE *pFile = fopen(pszFile, "r");
+#endif
+    if (!pFile)
+        printErr("Failed to open '%s': %s\n", pszFile, strerror(errno));
+    return pFile;
+}
+
+
+static RTEXITCODE compareFiles(FILE *pFile1, FILE *pFile2)
+{
+    if (!pFile1 || !pFile2)
+        return RTEXITCODE_FAILURE;
+
+    uint32_t    cMismatches = 1;
+    RTEXITCODE  rcRet       = RTEXITCODE_SUCCESS;
+    uint64_t    off         = 0;
+    for (;;)
+    {
+        uint8_t b1;
+        size_t cb1 = fread(&b1, sizeof(b1), 1, pFile1);
+        uint8_t b2;
+        size_t cb2 = fread(&b2, sizeof(b2), 1, pFile2);
+        if (cb1 != 1 || cb2 != 1)
+            break;
+        if (b1 != b2)
+        {
+            printErr("0x%x%08x: %#04x (%3d) != %#04x (%3d)\n", (uint32_t)(off >> 32), (uint32_t)off, b1, b1, b2, b2);
+            rcRet = RTEXITCODE_FAILURE;
+            cMismatches++;
+            if (cMismatches > 128)
+            {
+                printErr("Too many mismatches, giving up\n");
+                return rcRet;
+            }
+        }
+        off++;
+    }
+
+    if (!feof(pFile1) || !feof(pFile2))
+    {
+        if (!feof(pFile1) && ferror(pFile1))
+            rcRet = printErr("Read error on file #1.\n");
+        else if (!feof(pFile2) && ferror(pFile2))
+            rcRet = printErr("Read error on file #2.\n");
+        else if (!feof(pFile2))
+            rcRet = printErr("0x%x%08x: file #1 ends before file #2\n", (uint32_t)(off >> 32), (uint32_t)off);
+        else
+            rcRet = printErr("0x%x%08x: file #2 ends before file #1\n", (uint32_t)(off >> 32), (uint32_t)off);
+    }
+
+    return rcRet;
+}
+
+
+int main(int argc, char *argv[])
+{
+    RTEXITCODE rcExit;
+
+    if (argc == 3)
+    {
+        const char *pszFile1 = argv[1];
+        const char *pszFile2 = argv[2];
+        FILE       *pFile1 = openFile(pszFile1);
+        FILE       *pFile2 = openFile(pszFile2);
+        rcExit = compareFiles(pFile1, pFile2);
+        if (pFile1)
+            fclose(pFile1);
+        if (pFile2)
+            fclose(pFile2);
+    }
+    else
+        rcExit = printErr("Syntax error: usage: VBoxCmp <file1> <file2>\n");
+    return rcExit;
+}
+