Extensions for java.io.File

Appends an array of bytes to the content of this file.

fun File.appendBytes(array: ByteArray)

Appends text to the content of this file using UTF-8 or the specified charset.

fun File.appendText(
    text: String, 
    charset: Charset = Charsets.UTF_8)

Returns a new BufferedReader for reading the content of this file.

fun File.bufferedReader(
    charset: Charset = Charsets.UTF_8, 
    bufferSize: Int = DEFAULT_BUFFER_SIZE
): BufferedReader

Returns a new BufferedWriter for writing the content of this file.

fun File.bufferedWriter(
    charset: Charset = Charsets.UTF_8, 
    bufferSize: Int = DEFAULT_BUFFER_SIZE
): BufferedWriter

Copies this file with all its children to the specified destination target path. If some directories on the way to the destination are missing, then they will be created.

fun File.copyRecursively(
    target: File, 
    overwrite: Boolean = false, 
    onError: (File, IOException) -> OnErrorAction = { _, exception -> throw exception }
): Boolean

Copies this file to the given target file.

fun File.copyTo(
    target: File, 
    overwrite: Boolean = false, 
    bufferSize: Int = DEFAULT_BUFFER_SIZE
): File

Delete this file with all its children. Note that if this operation fails then partial deletion may have taken place.

fun File.deleteRecursively(): Boolean

Determines whether this file path ends with the path of other file.

fun File.endsWith(other: File): Boolean

Determines whether this file belongs to the same root as other and ends with all components of other in the same order. So if other has N components, last N components of this must be the same as in other. For relative other, this can belong to any root.

fun File.endsWith(other: String): Boolean

Returns the extension of this file (not including the dot), or an empty string if it doesn't have one.

val File.extension: String

Reads file by byte blocks and calls action for each block read. Block has default size which is implementation-dependent. This functions passes the byte array and amount of bytes in the array to the action function.

fun File.forEachBlock(
    action: (buffer: ByteArray, bytesRead: Int) -> Unit)

Reads file by byte blocks and calls action for each block read. This functions passes the byte array and amount of bytes in the array to the action function.

fun File.forEachBlock(
    blockSize: Int, 
    action: (buffer: ByteArray, bytesRead: Int) -> Unit)

Reads this file line by line using the specified charset and calls action for each line. Default charset is UTF-8.

fun File.forEachLine(
    charset: Charset = Charsets.UTF_8, 
    action: (line: String) -> Unit)

Constructs a new FileInputStream of this file and returns it as a result.

fun File.inputStream(): FileInputStream

Returns path of this File using the invariant separator '/' to separate the names in the name sequence.

val File.invariantSeparatorsPath: String

Determines whether this file has a root or it represents a relative path.

val File.isRooted: Boolean

Returns file's name without an extension.

val File.nameWithoutExtension: String

Removes all . and resolves all possible .. in this file name. For instance, File("/foo/./bar/gav/../baaz").normalize() is File("/foo/bar/baaz").

fun File.normalize(): File

Constructs a new FileOutputStream of this file and returns it as a result.

fun File.outputStream(): FileOutputStream

Returns a new PrintWriter for writing the content of this file.

fun File.printWriter(
    charset: Charset = Charsets.UTF_8
): PrintWriter

Gets the entire content of this file as a byte array.

fun File.readBytes(): ByteArray

Returns a new FileReader for reading the content of this file.

fun File.reader(
    charset: Charset = Charsets.UTF_8
): InputStreamReader

Reads the file content as a list of lines.

fun File.readLines(
    charset: Charset = Charsets.UTF_8
): List<String>

Gets the entire content of this file as a String using UTF-8 or specified charset.

fun File.readText(charset: Charset = Charsets.UTF_8): String

Calculates the relative path for this file from base file. Note that the base file is treated as a directory. If this file matches the base file, then a File with empty path will be returned.

fun File.relativeTo(base: File): File

Calculates the relative path for this file from base file. Note that the base file is treated as a directory. If this file matches the base file, then a File with empty path will be returned.

fun File.relativeToOrNull(base: File): File?

Calculates the relative path for this file from base file. Note that the base file is treated as a directory. If this file matches the base file, then a File with empty path will be returned.

fun File.relativeToOrSelf(base: File): File

Adds relative file to this, considering this as a directory. If relative has a root, relative is returned back. For instance, File("/foo/bar").resolve(File("gav")) is File("/foo/bar/gav"). This function is complementary with relativeTo, so f.resolve(g.relativeTo(f)) == g should be always true except for different roots case.

fun File.resolve(relative: File): File

Adds relative name to this, considering this as a directory. If relative has a root, relative is returned back. For instance, File("/foo/bar").resolve("gav") is File("/foo/bar/gav").

fun File.resolve(relative: String): File

Adds relative file to this parent directory. If relative has a root or this has no parent directory, relative is returned back. For instance, File("/foo/bar").resolveSibling(File("gav")) is File("/foo/gav").

fun File.resolveSibling(relative: File): File

Adds relative name to this parent directory. If relative has a root or this has no parent directory, relative is returned back. For instance, File("/foo/bar").resolveSibling("gav") is File("/foo/gav").

fun File.resolveSibling(relative: String): File

Determines whether this file belongs to the same root as other and starts with all components of other in the same order. So if other has N components, first N components of this must be the same as in other.

fun File.startsWith(other: File): Boolean

fun File.startsWith(other: String): Boolean

Calculates the relative path for this file from base file. Note that the base file is treated as a directory. If this file matches the base file, then an empty string will be returned.

fun File.toRelativeString(base: File): String

Calls the block callback giving it a sequence of all the lines in this file and closes the reader once the processing is complete.

fun <T> File.useLines(
    charset: Charset = Charsets.UTF_8, 
    block: (Sequence<String>) -> T
): T

Gets a sequence for visiting this directory and all its content.

fun File.walk(
    direction: FileWalkDirection = FileWalkDirection.TOP_DOWN
): FileTreeWalk

Gets a sequence for visiting this directory and all its content in bottom-up order. Depth-first search is used and directories are visited after all their files.

fun File.walkBottomUp(): FileTreeWalk

Gets a sequence for visiting this directory and all its content in top-down order. Depth-first search is used and directories are visited before all their files.

fun File.walkTopDown(): FileTreeWalk

Sets the content of this file as an array of bytes. If this file already exists, it becomes overwritten.

fun File.writeBytes(array: ByteArray)

Returns a new FileWriter for writing the content of this file.

fun File.writer(
    charset: Charset = Charsets.UTF_8
): OutputStreamWriter

Sets the content of this file as text encoded using UTF-8 or specified charset. If this file exists, it becomes overwritten.

fun File.writeText(
    text: String, 
    charset: Charset = Charsets.UTF_8)