Added file write support

README.md

@@ -3,18 +3,20 @@ This project is just starting but is intended to be both a command line tool and
 
 ## Current command line functionality
 1. Export files
-2. List any directory
-3. Display volume bitmap
-4. Create new volume
-5. Delete file
+2. Write files (currently only works with < 128K files)
+3. List any directory
+4. Display volume bitmap
+5. Create new volume
+6. Delete file
 
 ## Current library functionality
 1. Read block
 2. Write block
 3. Read file
-4. Delete file
-5. Create new volume
-6. Read volume bitmap
-7. Write volume bitmap
-8. Get list of file entries from any path
-9. Get volume header
+4. Write file
+5. Delete file
+6. Create new volume
+7. Read volume bitmap
+8. Write volume bitmap
+9. Get list of file entries from any path
+10. Get volume header

main.go

@@ -13,13 +13,15 @@ func main() {
 	var pathName string
 	var command string
 	var outFileName string
+	var inFileName string
 	var blockNumber int
 	var volumeSize int
 	var volumeName string
 	flag.StringVar(&fileName, "driveimage", "", "A ProDOS format drive image")
 	flag.StringVar(&pathName, "path", "", "Path name in ProDOS drive image")
 	flag.StringVar(&command, "command", "ls", "Command to execute: ls, get, put, volumebitmap, readblock, writeblock, createvolume, delete")
-	flag.StringVar(&outFileName, "outfile", "export.bin", "Name of file to write")
+	flag.StringVar(&outFileName, "outfile", "", "Name of file to write")
+	flag.StringVar(&inFileName, "infile", "", "Name of file to read")
 	flag.IntVar(&volumeSize, "volumesize", 65535, "Number of blocks to create the volume with")
 	flag.StringVar(&volumeName, "volumename", "NO.NAME", "Specifiy a name for the volume from 1 to 15 characters")
 	flag.IntVar(&blockNumber, "block", 0, "A block number to read/write from 0 to 65535")
@@ -36,7 +38,7 @@ func main() {
 		if err != nil {
 			os.Exit(1)
 		}
-		volumeHeader, fileEntries := prodos.ReadDirectory(file, pathName)
+		volumeHeader, _, fileEntries := prodos.ReadDirectory(file, pathName)
 		prodos.DumpDirectory(volumeHeader, fileEntries)
 	case "volumebitmap":
 		file, err := os.OpenFile(fileName, os.O_RDWR, 0755)
@@ -55,11 +57,28 @@ func main() {
 			os.Exit(1)
 		}
 		getFile := prodos.LoadFile(file, pathName)
+		if len(outFileName) == 0 {
+			_, outFileName = prodos.GetDirectoryAndFileNameFromPath(pathName)
+		}
 		outFile, err := os.Create(outFileName)
 		if err != nil {
 			os.Exit(1)
 		}
 		outFile.Write(getFile)
+	case "put":
+		file, err := os.OpenFile(fileName, os.O_RDWR, 0755)
+		if err != nil {
+			os.Exit(1)
+		}
+		if len(pathName) == 0 {
+			fmt.Println("Missing pathname")
+			os.Exit(1)
+		}
+		inFile, err := os.ReadFile(inFileName)
+		if err != nil {
+			os.Exit(1)
+		}
+		prodos.WriteFile(file, pathName, inFile)
 	case "readblock":
 		file, err := os.OpenFile(fileName, os.O_RDWR, 0755)
 		if err != nil {

prodos/bitmap.go

@@ -74,7 +74,21 @@ func CreateVolumeBitmap(numberOfBlocks int) []byte {
 	return volumeBitmap
 }
 
-func FindFreeBlocks(numberOfBlocks int) []int {
+func FindFreeBlocks(volumeBitmap []byte, numberOfBlocks int) []int {
+	blocks := make([]int, numberOfBlocks)
+
+	blocksFound := 0
+
+	for i := 0; i < len(volumeBitmap)*8; i++ {
+		if CheckFreeBlockInVolumeBitmap(volumeBitmap, i) {
+			blocks[blocksFound] = i
+			blocksFound++
+			if blocksFound == numberOfBlocks {
+				return blocks
+			}
+		}
+	}
+
 	return nil
 }
 
@@ -134,3 +148,31 @@ func FreeBlockInVolumeBitmap(volumeBitmap []byte, blockNumber int) {
 
 	volumeBitmap[byteToChange] |= byte(byteToOr)
 }
+
+func CheckFreeBlockInVolumeBitmap(volumeBitmap []byte, blockNumber int) bool {
+	bitToCheck := blockNumber % 8
+	byteToCheck := blockNumber / 8
+
+	byteToAnd := 0b00000000
+
+	switch bitToCheck {
+	case 0:
+		byteToAnd = 0b10000000
+	case 1:
+		byteToAnd = 0b01000000
+	case 2:
+		byteToAnd = 0b00100000
+	case 3:
+		byteToAnd = 0b00010000
+	case 4:
+		byteToAnd = 0b00001000
+	case 5:
+		byteToAnd = 0b00000100
+	case 6:
+		byteToAnd = 0b00000010
+	case 7:
+		byteToAnd = 0b00000001
+	}
+
+	return (volumeBitmap[byteToCheck] & byte(byteToAnd)) > 0
+}

prodos/bitmap_test.go

@@ -26,3 +26,30 @@ func TestCreateVolumeBitmap(t *testing.T) {
 		})
 	}
 }
+
+func TestCheckFreeBlockInVolumeBitmap(t *testing.T) {
+	var tests = []struct {
+		blocks int
+		want   bool
+	}{
+		{0, false},     // boot block
+		{1, false},     // SOS boot block
+		{2, false},     // volume root
+		{21, false},    // end of volume bitmap
+		{22, true},     // beginning of free space
+		{8192, true},   // more free space
+		{65534, true},  // last free block
+		{65535, false}, // can't use last block because volume size is 0xFFFF, not 0x10000
+	}
+
+	for _, tt := range tests {
+		testname := fmt.Sprintf("%d", tt.blocks)
+		t.Run(testname, func(t *testing.T) {
+			volumeBitMap := CreateVolumeBitmap(65535)
+			ans := CheckFreeBlockInVolumeBitmap(volumeBitMap, tt.blocks)
+			if ans != tt.want {
+				t.Errorf("got %t, want %t", ans, tt.want)
+			}
+		})
+	}
+}

prodos/directory.go

@@ -23,6 +23,8 @@ type VolumeHeader struct {
 type DirectoryHeader struct {
 	Name            string
 	ActiveFileCount int
+	StartingBlock   int
+	PreviousBlock   int
 	NextBlock       int
 }
 
@@ -53,11 +55,10 @@ type FileEntry struct {
 	DirectoryOffset int
 }
 
-func ReadDirectory(file *os.File, path string) (VolumeHeader, []FileEntry) {
+func ReadDirectory(file *os.File, path string) (VolumeHeader, DirectoryHeader, []FileEntry) {
 	buffer := ReadBlock(file, 2)
 
 	volumeHeader := parseVolumeHeader(buffer)
-	//dumpVolumeHeader(volumeHeader)
 
 	if len(path) == 0 {
 		path = fmt.Sprintf("/%s", volumeHeader.VolumeName)
@@ -66,17 +67,52 @@ func ReadDirectory(file *os.File, path string) (VolumeHeader, []FileEntry) {
 	path = strings.ToUpper(path)
 	paths := strings.Split(path, "/")
 
-	fileEntries := getFileEntriesInDirectory(file, 2, 1, paths)
+	directoryHeader, fileEntries := getFileEntriesInDirectory(file, 2, 1, paths)
 
-	return volumeHeader, fileEntries
+	return volumeHeader, directoryHeader, fileEntries
 }
 
-func getFileEntriesInDirectory(file *os.File, blockNumber int, currentPath int, paths []string) []FileEntry {
-	//fmt.Printf("Parsing '%s'...\n", paths[currentPath])
+func GetFreeFileEntryInDirectory(file *os.File, directory string) FileEntry {
+	_, directoryHeader, _ := ReadDirectory(file, directory)
+	DumpDirectoryHeader(directoryHeader)
+	blockNumber := directoryHeader.StartingBlock
+	buffer := ReadBlock(file, blockNumber)
+
+	entryOffset := 43 // start at offset after header
+	entryNumber := 2  // header is essentially the first entry so start at 2
+
+	for {
+		if entryNumber > 13 {
+			blockNumber = int(buffer[2]) + int(buffer[3])*256
+			// if we ran out of blocks in the directory, return empty
+			// TODO: expand the directory to add more entries
+			if blockNumber == 0 {
+				return FileEntry{}
+			}
+			// else read the next block in the directory
+			buffer = ReadBlock(file, blockNumber)
+			entryOffset = 4
+			entryNumber = 1
+		}
+		fileEntry := parseFileEntry(buffer[entryOffset:entryOffset+40], blockNumber, entryOffset)
+
+		if fileEntry.StorageType == StorageDeleted {
+			fileEntry.DirectoryBlock = blockNumber
+			fileEntry.DirectoryOffset = entryOffset
+			fileEntry.HeaderPointer = directoryHeader.StartingBlock
+			return fileEntry
+		}
+
+		entryNumber++
+		entryOffset += 39
+	}
+}
+
+func getFileEntriesInDirectory(file *os.File, blockNumber int, currentPath int, paths []string) (DirectoryHeader, []FileEntry) {
 
 	buffer := ReadBlock(file, blockNumber)
 
-	directoryHeader := parseDirectoryHeader(buffer)
+	directoryHeader := parseDirectoryHeader(buffer, blockNumber)
 
 	fileEntries := make([]FileEntry, directoryHeader.ActiveFileCount)
 	entryOffset := 43 // start at offset after header
@@ -89,7 +125,7 @@ func getFileEntriesInDirectory(file *os.File, blockNumber int, currentPath int,
 
 	if !matchedDirectory && (currentPath == len(paths)-1) {
 		// path not matched by last path part
-		return nil
+		return DirectoryHeader{}, nil
 	}
 
 	for {
@@ -97,24 +133,23 @@ func getFileEntriesInDirectory(file *os.File, blockNumber int, currentPath int,
 			entryOffset = 4
 			entryNumber = 1
 			if blockNumber == 0 {
-				return nil
+				return DirectoryHeader{}, nil
 			}
 			buffer = ReadBlock(file, nextBlock)
 			nextBlock = int(buffer[2]) + int(buffer[3])*256
 		}
 		fileEntry := parseFileEntry(buffer[entryOffset:entryOffset+40], blockNumber, entryOffset)
-		//DumpFileEntry(fileEntry)
 
 		if fileEntry.StorageType != StorageDeleted {
+			if matchedDirectory && activeEntries == directoryHeader.ActiveFileCount {
+				return directoryHeader, fileEntries[0:activeEntries]
+			}
 			if matchedDirectory {
 				fileEntries[activeEntries] = fileEntry
 			} else if !matchedDirectory && fileEntry.FileType == 15 && paths[currentPath+1] == fileEntry.FileName {
 				return getFileEntriesInDirectory(file, fileEntry.KeyPointer, currentPath+1, paths)
 			}
 			activeEntries++
-			if matchedDirectory && activeEntries == directoryHeader.ActiveFileCount {
-				return fileEntries[0:activeEntries]
-			}
 		}
 
 		entryNumber++
@@ -227,14 +262,17 @@ func parseVolumeHeader(buffer []byte) VolumeHeader {
 	return volumeHeader
 }
 
-func parseDirectoryHeader(buffer []byte) DirectoryHeader {
+func parseDirectoryHeader(buffer []byte, blockNumber int) DirectoryHeader {
+	previousBlock := int(buffer[0x00]) + int(buffer[0x01])*256
 	nextBlock := int(buffer[0x02]) + int(buffer[0x03])*256
 	filenameLength := buffer[0x04] & 15
 	name := string(buffer[0x05 : filenameLength+0x05])
 	fileCount := int(buffer[0x25]) + int(buffer[0x26])*256
 
 	directoryEntry := DirectoryHeader{
+		PreviousBlock:   previousBlock,
 		NextBlock:       nextBlock,
+		StartingBlock:   blockNumber,
 		Name:            name,
 		ActiveFileCount: fileCount,
 	}

prodos/file.go

@@ -3,6 +3,7 @@ package prodos
 import (
 	"os"
 	"strings"
+	"time"
 )
 
 func LoadFile(file *os.File, path string) []byte {
@@ -22,6 +23,71 @@ func LoadFile(file *os.File, path string) []byte {
 	return buffer
 }
 
+func WriteFile(file *os.File, path string, buffer []byte) {
+	directory, fileName := GetDirectoryAndFileNameFromPath(path)
+
+	DeleteFile(file, path)
+
+	// get list of blocks to write file to
+	blockList := CreateBlockList(file, len(buffer))
+
+	fileEntry := GetFreeFileEntryInDirectory(file, directory)
+
+	// seedling file
+	if len(buffer) <= 0x200 {
+		WriteBlock(file, blockList[0], buffer)
+		fileEntry.StorageType = StorageSeedling
+	}
+
+	// sapling file needs index block
+	if len(buffer) > 0x200 && len(buffer) <= 0x20000 {
+		fileEntry.StorageType = StorageSapling
+
+		// write index block with pointers to data blocks
+		indexBuffer := make([]byte, 512)
+		for i := 0; i < 256; i++ {
+			if i < len(blockList) {
+				indexBuffer[i] = byte(blockList[i] & 0x00FF)
+				indexBuffer[i+256] = byte(blockList[i] >> 8)
+			}
+		}
+		WriteBlock(file, blockList[0], indexBuffer)
+
+		// write all data blocks
+		blockBuffer := make([]byte, 512)
+		blockPointer := 0
+		blockIndexNumber := 1
+		for i := 0; i < len(buffer); i++ {
+			blockBuffer[blockPointer] = buffer[i]
+			if blockPointer == 512 {
+				WriteBlock(file, blockList[blockIndexNumber], blockBuffer)
+				blockPointer = 0
+				blockIndexNumber++
+			}
+			if i == len(buffer)-1 {
+				for j := blockPointer; j < 512; j++ {
+					blockBuffer[j] = 0
+				}
+				WriteBlock(file, blockList[blockIndexNumber], blockBuffer)
+			}
+		}
+	}
+
+	// TODO: add tree file
+
+	// add file entry to directory
+	fileEntry.FileName = fileName
+	fileEntry.BlocksUsed = len(blockList)
+	fileEntry.CreationTime = time.Now()
+	fileEntry.ModifiedTime = time.Now()
+	fileEntry.AuxType = 0x2000
+	fileEntry.EndOfFile = len(buffer)
+	fileEntry.FileType = 0x06
+	fileEntry.KeyPointer = blockList[0]
+
+	writeFileEntry(file, fileEntry)
+}
+
 func GetBlocklist(file *os.File, fileEntry FileEntry) []int {
 	blocks := make([]int, fileEntry.BlocksUsed)
 
@@ -46,21 +112,34 @@ func GetBlocklist(file *os.File, fileEntry FileEntry) []int {
 	return blocks
 }
 
-func GetFileEntry(file *os.File, path string) FileEntry {
-	path = strings.ToUpper(path)
-	paths := strings.Split(path, "/")
+func CreateBlockList(file *os.File, fileSize int) []int {
+	numberOfBlocks := fileSize / 512
+	if fileSize%512 > 0 {
+		numberOfBlocks++
+	}
+	if fileSize > 0x200 && fileSize <= 0x20000 {
+		numberOfBlocks++ // add index block
+	}
+	if fileSize > 0x20000 {
+		// add master index block
+		numberOfBlocks++
+		// add index blocks for each 128 blocks
+		numberOfBlocks += numberOfBlocks / 128
+		// add index block for any remaining blocks
+		if numberOfBlocks%128 > 0 {
+			numberOfBlocks++
+		}
+	}
+	volumeBitmap := ReadVolumeBitmap(file)
+	blockList := FindFreeBlocks(volumeBitmap, numberOfBlocks)
 
-	var directoryBuilder strings.Builder
-
-	for i := 1; i < len(paths)-1; i++ {
-		directoryBuilder.WriteString("/")
-		directoryBuilder.WriteString(paths[i])
+	return blockList
 }
 
-	directory := directoryBuilder.String()
-	fileName := paths[len(paths)-1]
+func GetFileEntry(file *os.File, path string) FileEntry {
+	directory, fileName := GetDirectoryAndFileNameFromPath(path)
 
-	_, fileEntries := ReadDirectory(file, directory)
+	_, _, fileEntries := ReadDirectory(file, directory)
 
 	if fileEntries == nil {
 		return FileEntry{}
@@ -77,8 +156,28 @@ func GetFileEntry(file *os.File, path string) FileEntry {
 	return fileEntry
 }
 
+func GetDirectoryAndFileNameFromPath(path string) (string, string) {
+	path = strings.ToUpper(path)
+	paths := strings.Split(path, "/")
+
+	var directoryBuilder strings.Builder
+
+	for i := 1; i < len(paths)-1; i++ {
+		directoryBuilder.WriteString("/")
+		directoryBuilder.WriteString(paths[i])
+	}
+
+	directory := directoryBuilder.String()
+	fileName := paths[len(paths)-1]
+
+	return directory, fileName
+}
+
 func DeleteFile(file *os.File, path string) {
 	fileEntry := GetFileEntry(file, path)
+	if fileEntry.StorageType == StorageDeleted {
+		return
+	}
 
 	// free the blocks
 	blocks := GetBlocklist(file, fileEntry)
@@ -95,7 +194,7 @@ func DeleteFile(file *os.File, path string) {
 
 	// decrement the directory entry count
 	directoryBlock := ReadBlock(file, fileEntry.HeaderPointer)
-	directoryHeader := parseDirectoryHeader(directoryBlock)
+	directoryHeader := parseDirectoryHeader(directoryBlock, fileEntry.HeaderPointer)
 
 	directoryHeader.ActiveFileCount--
 	writeDirectoryHeader(file, directoryHeader, fileEntry.HeaderPointer)

prodos/text.go

@@ -105,6 +105,14 @@ func DumpVolumeHeader(volumeHeader VolumeHeader) {
 	fmt.Printf("Total blocks: %d\n", volumeHeader.TotalBlocks)
 }
 
+func DumpDirectoryHeader(directoryHeader DirectoryHeader) {
+	fmt.Printf("Name: %s\n", directoryHeader.Name)
+	fmt.Printf("File count: %d\n", directoryHeader.ActiveFileCount)
+	fmt.Printf("Starting block: %04X\n", directoryHeader.StartingBlock)
+	fmt.Printf("Previous block: %04X\n", directoryHeader.PreviousBlock)
+	fmt.Printf("Next block: %04X\n", directoryHeader.NextBlock)
+}
+
 func DumpBlock(buffer []byte) {
 	for i := 0; i < len(buffer); i += 16 {
 		for j := i; j < i+16; j++ {