Initial commit.

.clang-format

@@ -0,0 +1,120 @@
+---
+Language:        Cpp
+AccessModifierOffset: -2
+AlignAfterOpenBracket: Align
+AlignConsecutiveAssignments: true
+AlignConsecutiveDeclarations: true
+AlignEscapedNewlines: Right
+AlignOperands:   true
+AlignTrailingComments: true
+AllowAllParametersOfDeclarationOnNextLine: false
+AllowShortBlocksOnASingleLine: true
+AllowShortCaseLabelsOnASingleLine: true
+AllowShortFunctionsOnASingleLine: All
+AllowShortIfStatementsOnASingleLine: Always
+AllowShortLoopsOnASingleLine: true
+AlwaysBreakAfterDefinitionReturnType: None
+AlwaysBreakAfterReturnType: None
+AlwaysBreakBeforeMultilineStrings: false
+BinPackArguments: false
+BinPackParameters: false
+BraceWrapping:
+    AfterClass:      true
+    AfterControlStatement: true
+    AfterEnum:       true
+    AfterFunction:   true
+    AfterNamespace:  true
+    AfterObjCDeclaration: true
+    AfterStruct:     true
+    AfterUnion:      true
+    AfterExternBlock: true
+    BeforeCatch:     true
+    BeforeElse:      true
+    IndentBraces:    false
+    SplitEmptyFunction: false
+    SplitEmptyRecord: false
+    SplitEmptyNamespace: false
+BreakBeforeBinaryOperators: None
+BreakBeforeBraces: Allman
+BreakBeforeInheritanceComma: false
+BreakBeforeTernaryOperators: true
+BreakConstructorInitializersBeforeComma: false
+BreakConstructorInitializers: BeforeColon
+BreakAfterJavaFieldAnnotations: false
+BreakStringLiterals: true
+ColumnLimit:     120
+CompactNamespaces: false
+ConstructorInitializerAllOnOneLineOrOnePerLine: false
+ConstructorInitializerIndentWidth: 4
+ContinuationIndentWidth: 4
+Cpp11BracedListStyle: true
+DerivePointerAlignment: false
+DisableFormat:   false
+ExperimentalAutoDetectBinPacking: false
+FixNamespaceComments: true
+ForEachMacros:
+    - foreach
+    - Q_FOREACH
+    - BOOST_FOREACH
+IncludeBlocks:   Regroup
+IncludeCategories:
+    - Regex:           '^(<winsock2.h>)'
+      Priority:        -3
+      SortPriority:    -4
+    - Regex:           '^(<windows.h>)'
+      Priority:        -3
+      SortPriority:    -3
+    - Regex:           '^(<aaruformat.h>)'
+      Priority:        1
+      SortPriority:    -1
+    - Regex:           '^(<.*)'
+      Priority:        -2
+      SortPriority:    -2
+    - Regex:           '^("(win32|windows))'
+      Priority:        1
+      SortPriority:    -1
+    - Regex:           '.*'
+      Priority:        0
+      SortPriority:    0
+IncludeIsMainRegex: '(Test)?$'
+IndentCaseLabels: true
+IndentPPDirectives: None
+IndentWidth:     4
+IndentWrappedFunctionNames: true
+JavaScriptQuotes: Double
+JavaScriptWrapImports: true
+KeepEmptyLinesAtTheStartOfBlocks: false
+MacroBlockBegin: ''
+MacroBlockEnd:   ''
+MaxEmptyLinesToKeep: 1
+NamespaceIndentation: All
+ObjCBlockIndentWidth: 4
+ObjCSpaceAfterProperty: false
+ObjCSpaceBeforeProtocolList: true
+PenaltyBreakAssignment: 2
+PenaltyBreakBeforeFirstCallParameter: 19
+PenaltyBreakComment: 300
+PenaltyBreakFirstLessLess: 120
+PenaltyBreakString: 1000
+PenaltyExcessCharacter: 1000000
+PenaltyReturnTypeOnItsOwnLine: 60
+PointerAlignment: Left
+ReflowComments:  true
+SortIncludes:    true
+SortUsingDeclarations: true
+SpaceAfterCStyleCast: false
+SpaceAfterTemplateKeyword: false
+SpaceBeforeAssignmentOperators: true
+SpaceBeforeParens: Never
+SpaceInEmptyParentheses: false
+SpacesBeforeTrailingComments: 1
+SpacesInAngles:  false
+SpacesInContainerLiterals: false
+SpacesInCStyleCastParentheses: false
+SpacesInParentheses: false
+SpacesInSquareBrackets: false
+Standard:        Cpp11
+TabWidth:        8
+UseTab:          Never
+...
+

.gitignore

@@ -0,0 +1,254 @@
+### C++ template
+# Prerequisites
+*.d
+
+# Compiled Object files
+*.slo
+*.lo
+*.o
+*.obj
+
+# Precompiled Headers
+*.gch
+*.pch
+
+# Compiled Dynamic libraries
+*.so
+*.dylib
+*.dll
+
+# Fortran module files
+*.mod
+*.smod
+
+# Compiled Static libraries
+*.lai
+*.la
+*.a
+*.lib
+
+# Executables
+*.exe
+*.out
+*.app
+
+### VisualStudioCode template
+.vscode/*
+!.vscode/settings.json
+!.vscode/tasks.json
+!.vscode/launch.json
+!.vscode/extensions.json
+*.code-workspace
+
+# Local History for Visual Studio Code
+.history/
+
+### C template
+# Prerequisites
+*.d
+
+# Object files
+*.o
+*.ko
+*.obj
+*.elf
+
+# Linker output
+*.ilk
+*.map
+*.exp
+
+# Precompiled Headers
+*.gch
+*.pch
+
+# Libraries
+*.lib
+*.a
+*.la
+*.lo
+
+# Shared objects (inc. Windows DLLs)
+*.dll
+*.so
+*.so.*
+*.dylib
+
+# Executables
+*.exe
+*.out
+*.app
+*.i*86
+*.x86_64
+*.hex
+
+# Debug files
+*.dSYM/
+*.su
+*.idb
+*.pdb
+
+# Kernel Module Compile Results
+*.mod*
+*.cmd
+.tmp_versions/
+modules.order
+Module.symvers
+Mkfile.old
+dkms.conf
+
+### JetBrains template
+# Covers JetBrains IDEs: IntelliJ, RubyMine, PhpStorm, AppCode, PyCharm, CLion, Android Studio, WebStorm and Rider
+# Reference: https://intellij-support.jetbrains.com/hc/en-us/articles/206544839
+
+# User-specific stuff
+.idea/**/workspace.xml
+.idea/**/tasks.xml
+.idea/**/usage.statistics.xml
+.idea/**/dictionaries
+.idea/**/shelf
+
+# Generated files
+.idea/**/contentModel.xml
+
+# Sensitive or high-churn files
+.idea/**/dataSources/
+.idea/**/dataSources.ids
+.idea/**/dataSources.local.xml
+.idea/**/sqlDataSources.xml
+.idea/**/dynamic.xml
+.idea/**/uiDesigner.xml
+.idea/**/dbnavigator.xml
+
+# Gradle
+.idea/**/gradle.xml
+.idea/**/libraries
+
+# Gradle and Maven with auto-import
+# When using Gradle or Maven with auto-import, you should exclude module files,
+# since they will be recreated, and may cause churn.  Uncomment if using
+# auto-import.
+# .idea/artifacts
+# .idea/compiler.xml
+# .idea/jarRepositories.xml
+# .idea/modules.xml
+# .idea/*.iml
+# .idea/modules
+# *.iml
+# *.ipr
+
+# CMake
+cmake-build-*/
+
+# Mongo Explorer plugin
+.idea/**/mongoSettings.xml
+
+# File-based project format
+*.iws
+
+# IntelliJ
+out/
+
+# mpeltonen/sbt-idea plugin
+.idea_modules/
+
+# JIRA plugin
+atlassian-ide-plugin.xml
+
+# Cursive Clojure plugin
+.idea/replstate.xml
+
+# Crashlytics plugin (for Android Studio and IntelliJ)
+com_crashlytics_export_strings.xml
+crashlytics.properties
+crashlytics-build.properties
+fabric.properties
+
+# Editor-based Rest Client
+.idea/httpRequests
+
+# Android studio 3.1+ serialized cache file
+.idea/caches/build_file_checksums.ser
+
+### Linux template
+*~
+
+# temporary files which can be created if a process still has a handle open of a deleted file
+.fuse_hidden*
+
+# KDE directory preferences
+.directory
+
+# Linux trash folder which might appear on any partition or disk
+.Trash-*
+
+# .nfs files are created when an open file is removed but is still being accessed
+.nfs*
+
+### CMake template
+CMakeLists.txt.user
+CMakeCache.txt
+CMakeFiles
+CMakeScripts
+Testing
+Makefile
+cmake_install.cmake
+install_manifest.txt
+compile_commands.json
+CTestTestfile.cmake
+_deps
+
+### Windows template
+# Windows thumbnail cache files
+Thumbs.db
+Thumbs.db:encryptable
+ehthumbs.db
+ehthumbs_vista.db
+
+# Dump file
+*.stackdump
+
+# Folder config file
+[Dd]esktop.ini
+
+# Recycle Bin used on file shares
+$RECYCLE.BIN/
+
+# Windows Installer files
+*.cab
+*.msi
+*.msix
+*.msm
+*.msp
+
+# Windows shortcuts
+*.lnk
+
+### macOS template
+# General
+.DS_Store
+.AppleDouble
+.LSOverride
+
+# Icon must end with two \r
+Icon
+
+# Thumbnails
+._*
+
+# Files that might appear in the root of a volume
+.DocumentRevisions-V100
+.fseventsd
+.Spotlight-V100
+.TemporaryItems
+.Trashes
+.VolumeIcon.icns
+.com.apple.timemachine.donotpresent
+
+# Directories potentially created on remote AFP share
+.AppleDB
+.AppleDesktop
+Network Trash Folder
+Temporary Items
+.apdisk
+

CMakeLists.txt

@@ -0,0 +1,6 @@
+cmake_minimum_required(VERSION 3.23)
+project(dddiff C)
+
+set(CMAKE_C_STANDARD 99)
+
+add_executable(dddiff main.c)

main.c

@@ -0,0 +1,132 @@
+/*
+ * Copyright (c) 2012 Natalia Portillo.
+ *
+ * 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, version 3.
+ *
+ * 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 <http://www.gnu.org/licenses/>.
+ */
+
+#include <fcntl.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#define BLOCK_SIZE 65536
+
+void show_usage() { printf("Usage: dd-diff <input_path> <output_path> [block_size]\n"); }
+
+int main(int argc, char** argv)
+{
+    int     block_size = BLOCK_SIZE;
+    ssize_t in_read, out_read, to_process, total_written = 0;
+    int     fd_in, fd_out;
+    char *  in_buf, *out_buf;
+    int     i, dif;
+    off_t   last_pos, current_pos;
+
+    printf("dd-diff A DD that only writes changed blocks.\n");
+    printf("Copyright (C) 2022 Natalia Portillo\n");
+
+    if(argc != 3 && argc != 4)
+    {
+        show_usage();
+        return 1;
+    }
+
+    if(argc == 4)
+    {
+        block_size = atoi(argv[3]);
+        if(block_size == 0) block_size = BLOCK_SIZE;
+    }
+
+    in_buf = malloc(block_size);
+
+    if(in_buf == NULL)
+    {
+        printf("Error: could not allocate memory.\n");
+        return 1;
+    }
+
+    out_buf = malloc(block_size);
+
+    if(out_buf == NULL)
+    {
+        printf("Error: could not allocate memory.\n");
+        free(out_buf);
+        return 1;
+    }
+
+    fd_in = open(argv[1], O_RDONLY);
+
+    if(fd_in < 0)
+    {
+        printf("Error opening input file.\n");
+        free(in_buf);
+        free(out_buf);
+        return 1;
+    }
+
+    fd_out = open(argv[2], O_RDWR);
+
+    if(fd_out < 0)
+    {
+        printf("Error opening output file.\n");
+        free(in_buf);
+        free(out_buf);
+        return 1;
+    }
+
+    last_pos = lseek(fd_in, 0, SEEK_END);
+    lseek(fd_in, 0, SEEK_SET);
+
+    in_read = read(fd_in, in_buf, block_size);
+
+    while(in_read > 0)
+    {
+        current_pos = lseek(fd_in, 0, SEEK_CUR);
+        printf("Processing position %ld of %ld (%f%%)\n",
+               current_pos,
+               last_pos,
+               ((float)current_pos * 100.0) / (float)last_pos);
+
+        out_read = read(fd_out, out_buf, block_size);
+
+        to_process = in_read;
+        if(out_read < to_process) to_process = out_read;
+
+        dif = false;
+        for(i = 0; i < to_process; i++)
+        {
+            if(in_buf[i] != out_buf[i])
+            {
+                dif = true;
+                break;
+            }
+        }
+
+        if(dif)
+        {
+            lseek(fd_in, -in_read, SEEK_CUR);
+            lseek(fd_out, -out_read, SEEK_CUR);
+            total_written += write(fd_out, in_buf, to_process);
+        }
+
+        in_read = read(fd_in, in_buf, block_size);
+    }
+
+    close(fd_in);
+    close(fd_out);
+    free(in_buf);
+    free(out_buf);
+
+    return 0;
+}