"bufio"
"encoding/binary"
"errors"
"hash"
"hash/crc32"
"internal/godebug"
"io"
"io/fs"
"os"
"path"
"path/filepath"
"slices"
"strings"
"sync"
"time"
"compress/flate"
"errors"
"io"
"sync"
"io/fs"
"path"
"time"
"bufio"
"encoding/binary"
"errors"
"hash"
"hash/crc32"
"io"
"io/fs"
"strings"
"unicode/utf8"
Compression methods.
const Deflate uint16 = 8var ErrAlgorithm = *ast.CallExprvar ErrChecksum = *ast.CallExprvar ErrFormat = *ast.CallExprvar ErrInsecurePath = *ast.CallExprCompression methods.
const Store uint16 = 0var compressors sync.MapConstants for the first byte in CreatorVersion.
const creatorFAT = 0const creatorMacOSX = 19const creatorNTFS = 11const creatorUnix = 3const creatorVFAT = 14const dataDescriptor64Len = 24const dataDescriptorLen = 16const dataDescriptorSignature = 0x08074b50var decompressors sync.Mapconst directory64EndLen = 56const directory64EndSignature = 0x06064b50const directory64LocLen = 20const directory64LocSignature = 0x07064b50const directoryEndLen = 22const directoryEndSignature = 0x06054b50const directoryHeaderLen = 46const directoryHeaderSignature = 0x02014b50var dotFile = *ast.UnaryExprvar errLongExtra = *ast.CallExprvar errLongName = *ast.CallExprconst extTimeExtraID = 0x5455const fileHeaderLen = 30const fileHeaderSignature = 0x04034b50var flateReaderPool sync.Poolvar flateWriterPool sync.Poolconst infoZipUnixExtraID = 0x5855const msdosDir = 0x10const msdosReadOnly = 0x01const ntfsExtraID = 0x000aconst s_IFBLK = 0x6000const s_IFCHR = 0x2000const s_IFDIR = 0x4000const s_IFIFO = 0x1000const s_IFLNK = 0xa000Unix constants. The specification doesn't mention them, but these seem to be the values agreed on by tools.
const s_IFMT = 0xf000const s_IFREG = 0x8000const s_IFSOCK = 0xc000const s_ISGID = 0x400const s_ISUID = 0x800const s_ISVTX = 0x200Limits for non zip64 files.
const uint16max = *ast.BinaryExprconst uint32max = *ast.BinaryExprconst unixExtraID = 0x000dExtra header IDs. IDs 0..31 are reserved for official use by PKWARE. IDs above that range are defined by third-party vendors. Since ZIP lacked high precision timestamps (nor an official specification of the timezone used for the date fields), many competing extra fields have been invented. Pervasive use effectively makes them "official". See http://mdfs.net/Docs/Comp/Archiving/Zip/ExtraField
const zip64ExtraID = 0x0001Version numbers.
const zipVersion20 = 20const zipVersion45 = 45var zipinsecurepath = *ast.CallExprA Compressor returns a new compressing writer, writing to w. The WriteCloser's Close method must be used to flush pending data to w. The Compressor itself must be safe to invoke from multiple goroutines simultaneously, but each returned writer will be used only by one goroutine at a time.
type Compressor func(w io.Writer) (io.WriteCloser, error)A Decompressor returns a new decompressing reader, reading from r. The [io.ReadCloser]'s Close method must be used to release associated resources. The Decompressor itself must be safe to invoke from multiple goroutines simultaneously, but each returned reader will be used only by one goroutine at a time.
type Decompressor func(r io.Reader) io.ReadClosertype readBuf []bytetype writeBuf []bytetype fileInfoDirEntry interface {
fs.FileInfo
fs.DirEntry
}A File is a single file in a ZIP archive. The file information is in the embedded [FileHeader]. The file content can be accessed by calling [File.Open].
type File struct {
FileHeader
zip *Reader
zipr io.ReaderAt
headerOffset int64
zip64 bool
}FileHeader describes a file within a ZIP file. See the [ZIP specification] for details. [ZIP specification]: https://support.pkware.com/pkzip/appnote
type FileHeader struct {
Name string
Comment string
NonUTF8 bool
CreatorVersion uint16
ReaderVersion uint16
Flags uint16
Method uint16
Modified time.Time
ModifiedTime uint16
ModifiedDate uint16
CRC32 uint32
CompressedSize uint32
UncompressedSize uint32
CompressedSize64 uint64
UncompressedSize64 uint64
Extra []byte
ExternalAttrs uint32
}A ReadCloser is a [Reader] that must be closed when no longer needed.
type ReadCloser struct {
f *os.File
Reader
}A Reader serves content from a ZIP archive.
type Reader struct {
r io.ReaderAt
File []*File
Comment string
decompressors map[uint16]Decompressor
baseOffset int64
fileListOnce sync.Once
fileList []fileListEntry
}Writer implements a zip file writer.
type Writer struct {
cw *countWriter
dir []*header
last *fileWriter
closed bool
compressors map[uint16]Compressor
comment string
testHookCloseSizeOffset func(size uint64, offset uint64)
}type checksumReader struct {
rc io.ReadCloser
hash hash.Hash32
nread uint64
f *File
desr io.Reader
err error
}type countWriter struct {
w io.Writer
count int64
}type dirReader struct {
err error
}type dirWriter struct {
}type directoryEnd struct {
diskNbr uint32
dirDiskNbr uint32
dirRecordsThisDisk uint64
directoryRecords uint64
directorySize uint64
directoryOffset uint64
commentLen uint16
comment string
}A fileListEntry is a File and its ename. If file == nil, the fileListEntry describes a directory without metadata.
type fileListEntry struct {
name string
file *File
isDir bool
isDup bool
}type fileWriter struct {
*header
zipw io.Writer
rawCount *countWriter
comp io.WriteCloser
compCount *countWriter
crc32 hash.Hash32
closed bool
}type header struct {
*FileHeader
offset uint64
raw bool
}headerFileInfo implements [fs.FileInfo].
type headerFileInfo struct {
fh *FileHeader
}type nopCloser struct {
io.Writer
}type openDir struct {
e *fileListEntry
files []fileListEntry
offset int
}type pooledFlateReader struct {
mu sync.Mutex
fr io.ReadCloser
}type pooledFlateWriter struct {
mu sync.Mutex
fw *flate.Writer
}AddFS adds the files from fs.FS to the archive. It walks the directory tree starting at the root of the filesystem adding each file to the zip using deflate while maintaining the directory structure.
func (w *Writer) AddFS(fsys fs.FS) errorfunc (r *dirReader) Close() errorfunc (w *pooledFlateWriter) Close() errorfunc (w nopCloser) Close() errorfunc (d *openDir) Close() errorClose closes the Zip file, rendering it unusable for I/O.
func (rc *ReadCloser) Close() errorfunc (r *pooledFlateReader) Close() errorfunc (r *checksumReader) Close() errorClose finishes writing the zip file by writing the central directory. It does not close the underlying writer.
func (w *Writer) Close() errorCopy copies the file f (obtained from a [Reader]) into w. It copies the raw form directly bypassing decompression, compression, and validation.
func (w *Writer) Copy(f *File) errorCreate adds a file to the zip file using the provided name. It returns a [Writer] to which the file contents should be written. The file contents will be compressed using the [Deflate] method. The name must be a relative path: it must not start with a drive letter (e.g. C:) or leading slash, and only forward slashes are allowed. To create a directory instead of a file, add a trailing slash to the name. Duplicate names will not overwrite previous entries and are appended to the zip file. The file's contents must be written to the [io.Writer] before the next call to [Writer.Create], [Writer.CreateHeader], or [Writer.Close].
func (w *Writer) Create(name string) (io.Writer, error)CreateHeader adds a file to the zip archive using the provided [FileHeader] for the file metadata. [Writer] takes ownership of fh and may mutate its fields. The caller must not modify fh after calling [Writer.CreateHeader]. This returns a [Writer] to which the file contents should be written. The file's contents must be written to the io.Writer before the next call to [Writer.Create], [Writer.CreateHeader], [Writer.CreateRaw], or [Writer.Close].
func (w *Writer) CreateHeader(fh *FileHeader) (io.Writer, error)CreateRaw adds a file to the zip archive using the provided [FileHeader] and returns a [Writer] to which the file contents should be written. The file's contents must be written to the io.Writer before the next call to [Writer.Create], [Writer.CreateHeader], [Writer.CreateRaw], or [Writer.Close]. In contrast to [Writer.CreateHeader], the bytes passed to Writer are not compressed. CreateRaw's argument is stored in w. If the argument is a pointer to the embedded [FileHeader] in a [File] obtained from a [Reader] created from in-memory data, then w will refer to all of that memory.
func (w *Writer) CreateRaw(fh *FileHeader) (io.Writer, error)DataOffset returns the offset of the file's possibly-compressed data, relative to the beginning of the zip file. Most callers should instead use [File.Open], which transparently decompresses data and verifies checksums.
func (f *File) DataOffset() (offset int64, err error)FileInfo returns an fs.FileInfo for the [FileHeader].
func (h *FileHeader) FileInfo() fs.FileInfoFileInfoHeader creates a partially-populated [FileHeader] from an fs.FileInfo. Because fs.FileInfo's Name method returns only the base name of the file it describes, it may be necessary to modify the Name field of the returned header to provide the full path name of the file. If compression is desired, callers should set the FileHeader.Method field; it is unset by default.
func FileInfoHeader(fi fs.FileInfo) (*FileHeader, error)Flush flushes any buffered data to the underlying writer. Calling Flush is not normally necessary; calling Close is sufficient.
func (w *Writer) Flush() errorfunc (f *fileListEntry) Info() (fs.FileInfo, error)func (fi headerFileInfo) Info() (fs.FileInfo, error)func (f *fileListEntry) IsDir() boolfunc (fi headerFileInfo) IsDir() boolfunc (fi headerFileInfo) ModTime() time.Timefunc (f *fileListEntry) ModTime() time.TimeModTime returns the modification time in UTC using the legacy [ModifiedDate] and [ModifiedTime] fields. Deprecated: Use [Modified] instead.
func (h *FileHeader) ModTime() time.TimeMode returns the permission and mode bits for the [FileHeader].
func (h *FileHeader) Mode() (mode fs.FileMode)func (fi headerFileInfo) Mode() fs.FileModefunc (f *fileListEntry) Mode() fs.FileModeOnly used for directories.
func (f *fileListEntry) Name() stringfunc (fi headerFileInfo) Name() stringNewReader returns a new [Reader] reading from r, which is assumed to have the given size in bytes. If any file inside the archive uses a non-local name (as defined by [filepath.IsLocal]) or a name containing backslashes and the GODEBUG environment variable contains `zipinsecurepath=0`, NewReader returns the reader with an [ErrInsecurePath] error. A future version of Go may introduce this behavior by default. Programs that want to accept non-local names can ignore the [ErrInsecurePath] error and use the returned reader.
func NewReader(r io.ReaderAt, size int64) (*Reader, error)NewWriter returns a new [Writer] writing a zip file to w.
func NewWriter(w io.Writer) *WriterOpen opens the named file in the ZIP archive, using the semantics of fs.FS.Open: paths are always slash separated, with no leading / or ../ elements.
func (r *Reader) Open(name string) (fs.File, error)Open returns a [ReadCloser] that provides access to the [File]'s contents. Multiple files may be read concurrently.
func (f *File) Open() (io.ReadCloser, error)OpenRaw returns a [Reader] that provides access to the [File]'s contents without decompression.
func (f *File) OpenRaw() (io.Reader, error)OpenReader will open the Zip file specified by name and return a ReadCloser. If any file inside the archive uses a non-local name (as defined by [filepath.IsLocal]) or a name containing backslashes and the GODEBUG environment variable contains `zipinsecurepath=0`, OpenReader returns the reader with an ErrInsecurePath error. A future version of Go may introduce this behavior by default. Programs that want to accept non-local names can ignore the ErrInsecurePath error and use the returned reader.
func OpenReader(name string) (*ReadCloser, error)func (r *dirReader) Read([]byte) (int, error)func (d *openDir) Read([]byte) (int, error)func (r *pooledFlateReader) Read(p []byte) (n int, err error)func (r *checksumReader) Read(b []byte) (n int, err error)func (d *openDir) ReadDir(count int) ([]fs.DirEntry, error)RegisterCompressor registers or overrides a custom compressor for a specific method ID. If a compressor for a given method is not found, [Writer] will default to looking up the compressor at the package level.
func (w *Writer) RegisterCompressor(method uint16, comp Compressor)RegisterCompressor registers custom compressors for a specified method ID. The common methods [Store] and [Deflate] are built in.
func RegisterCompressor(method uint16, comp Compressor)RegisterDecompressor allows custom decompressors for a specified method ID. The common methods [Store] and [Deflate] are built in.
func RegisterDecompressor(method uint16, dcomp Decompressor)RegisterDecompressor registers or overrides a custom decompressor for a specific method ID. If a decompressor for a given method is not found, [Reader] will default to looking up the decompressor at the package level.
func (r *Reader) RegisterDecompressor(method uint16, dcomp Decompressor)SetComment sets the end-of-central-directory comment field. It can only be called before [Writer.Close].
func (w *Writer) SetComment(comment string) errorSetModTime sets the [Modified], [ModifiedTime], and [ModifiedDate] fields to the given time in UTC. Deprecated: Use [Modified] instead.
func (h *FileHeader) SetModTime(t time.Time)SetMode changes the permission and mode bits for the [FileHeader].
func (h *FileHeader) SetMode(mode fs.FileMode)SetOffset sets the offset of the beginning of the zip data within the underlying writer. It should be used when the zip data is appended to an existing file, such as a binary executable. It must be called before any data is written.
func (w *Writer) SetOffset(n int64)func (fi headerFileInfo) Size() int64func (f *fileListEntry) Size() int64func (d *openDir) Stat() (fs.FileInfo, error)func (r *checksumReader) Stat() (fs.FileInfo, error)func (f *fileListEntry) String() stringfunc (fi headerFileInfo) String() stringfunc (f *fileListEntry) Sys() anyfunc (fi headerFileInfo) Sys() anyfunc (fi headerFileInfo) Type() fs.FileModefunc (f *fileListEntry) Type() fs.FileModefunc (w *fileWriter) Write(p []byte) (int, error)func (dirWriter) Write(b []byte) (int, error)func (w *countWriter) Write(p []byte) (int, error)func (w *pooledFlateWriter) Write(p []byte) (n int, err error)func (w *fileWriter) close() errorfunc (w *Writer) compressor(method uint16) Compressorfunc compressor(method uint16) Compressorfunc decompressor(method uint16) Decompressorfunc (r *Reader) decompressor(method uint16) DecompressordetectUTF8 reports whether s is a valid UTF-8 string, and whether the string must be considered UTF-8 encoding (i.e., not compatible with CP-437, ASCII, or any other common encoding).
func detectUTF8(s string) (valid bool, require bool)func fileEntryCompare(x string, y string) intfunc fileModeToUnixMode(mode fs.FileMode) uint32findBodyOffset does the minimum work to verify the file has a header and returns the file body offset.
func (f *File) findBodyOffset() (int64, error)findDirectory64End tries to read the zip64 locator just before the directory end and returns the offset of the zip64 directory end if found.
func findDirectory64End(r io.ReaderAt, directoryEndOffset int64) (int64, error)func findSignatureInBlock(b []byte) intfunc (h *FileHeader) hasDataDescriptor() boolfunc (r *Reader) init(rdr io.ReaderAt, size int64) errorfunc init()func (r *Reader) initFileList()isZip64 reports whether the file size exceeds the 32 bit limit
func (h *FileHeader) isZip64() boolmsDosTimeToTime converts an MS-DOS date and time into a time.Time. The resolution is 2s. See: https://learn.microsoft.com/en-us/windows/win32/api/winbase/nf-winbase-dosdatetimetofiletime
func msDosTimeToTime(dosDate uint16, dosTime uint16) time.Timefunc msdosModeToFileMode(m uint32) (mode fs.FileMode)func newFlateReader(r io.Reader) io.ReadCloserfunc newFlateWriter(w io.Writer) io.WriteCloserfunc (r *Reader) openLookup(name string) *fileListEntryfunc (r *Reader) openReadDir(dir string) []fileListEntryprepare performs the bookkeeping operations required at the start of CreateHeader and CreateRaw.
func (w *Writer) prepare(fh *FileHeader) errorfunc readDataDescriptor(r io.Reader, f *File) errorreadDirectory64End reads the zip64 directory end and updates the directory end with the zip64 directory end values.
func readDirectory64End(r io.ReaderAt, offset int64, d *directoryEnd) (err error)func readDirectoryEnd(r io.ReaderAt, size int64) (dir *directoryEnd, baseOffset int64, err error)readDirectoryHeader attempts to read a directory header from r. It returns io.ErrUnexpectedEOF if it cannot read a complete header, and ErrFormat if it doesn't find a valid header signature.
func readDirectoryHeader(f *File, r io.Reader) errorfunc split(name string) (dir string, elem string, isDir bool)func (f *fileListEntry) stat() (fileInfoDirEntry, error)func (b *readBuf) sub(n int) readBuftimeToMsDosTime converts a time.Time to an MS-DOS date and time. The resolution is 2s. See: https://learn.microsoft.com/en-us/windows/win32/api/winbase/nf-winbase-filetimetodosdatetime
func timeToMsDosTime(t time.Time) (fDate uint16, fTime uint16)timeZone returns a *time.Location based on the provided offset. If the offset is non-sensible, then this uses an offset of zero.
func timeZone(offset time.Duration) *time.LocationtoValidName coerces name to be a valid name for fs.FS.Open.
func toValidName(name string) stringfunc (b *readBuf) uint16() uint16func (b *writeBuf) uint16(v uint16)func (b *readBuf) uint32() uint32func (b *writeBuf) uint32(v uint32)func (b *readBuf) uint64() uint64func (b *writeBuf) uint64(v uint64)func (b *readBuf) uint8() uint8func (b *writeBuf) uint8(v uint8)func unixModeToFileMode(m uint32) fs.FileModefunc (w *fileWriter) writeDataDescriptor() errorfunc writeHeader(w io.Writer, h *header) errorGenerated with Arrow