package zip

Import Path
	archive/zip (on go.dev)

Dependency Relation
	imports 17 packages, and imported by 0 packages

Involved Source Files reader.go register.go Package zip provides support for reading and writing ZIP archives. See the [ZIP specification] for details. This package does not support disk spanning. A note about ZIP64: To be backwards compatible the FileHeader has both 32 and 64 bit Size fields. The 64 bit fields will always contain the correct value and for normal archives both fields will be the same. For files requiring the ZIP64 format the 32 bit fields will be 0xffffffff and the 64 bit fields must be used instead. writer.go
Code Examples package main import ( "archive/zip" "fmt" "io" "log" "os" ) func main() { // Open a zip archive for reading. r, err := zip.OpenReader("testdata/readme.zip") if err != nil { log.Fatal(err) } defer r.Close() // Iterate through the files in the archive, // printing some of their contents. for _, f := range r.File { fmt.Printf("Contents of %s:\n", f.Name) rc, err := f.Open() if err != nil { log.Fatal(err) } _, err = io.CopyN(os.Stdout, rc, 68) if err != nil { log.Fatal(err) } rc.Close() fmt.Println() } } package main import ( "archive/zip" "bytes" "log" ) func main() { // Create a buffer to write our archive to. buf := new(bytes.Buffer) // Create a new zip archive. w := zip.NewWriter(buf) // Add some files to the archive. var files = []struct { Name, Body string }{ {"readme.txt", "This archive contains some text files."}, {"gopher.txt", "Gopher names:\nGeorge\nGeoffrey\nGonzo"}, {"todo.txt", "Get animal handling licence.\nWrite more examples."}, } for _, file := range files { f, err := w.Create(file.Name) if err != nil { log.Fatal(err) } _, err = f.Write([]byte(file.Body)) if err != nil { log.Fatal(err) } } // Make sure to check the error on Close. err := w.Close() if err != nil { log.Fatal(err) } } package main import ( "archive/zip" "bytes" "compress/flate" "io" ) func main() { // Override the default Deflate compressor with a higher compression level. // Create a buffer to write our archive to. buf := new(bytes.Buffer) // Create a new zip archive. w := zip.NewWriter(buf) // Register a custom Deflate compressor. w.RegisterCompressor(zip.Deflate, func(out io.Writer) (io.WriteCloser, error) { return flate.NewWriter(out, flate.BestCompression) }) // Proceed to add files to w. }
Package-Level Type Names (total 7)
/* sort by: | */
A 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. func RegisterCompressor(method uint16, comp Compressor) func (*Writer).RegisterCompressor(method uint16, comp Compressor)
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. func RegisterDecompressor(method uint16, dcomp Decompressor) func (*Reader).RegisterDecompressor(method uint16, dcomp Decompressor)
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]. FileHeader FileHeader CRC32 is the CRC32 checksum of the file content. Comment is any arbitrary user-defined string shorter than 64KiB. CompressedSize is the compressed size of the file in bytes. If either the uncompressed or compressed size of the file does not fit in 32 bits, CompressedSize is set to ^uint32(0). Deprecated: Use CompressedSize64 instead. CompressedSize64 is the compressed size of the file in bytes. FileHeader.CreatorVersion uint16 // Meaning depends on CreatorVersion FileHeader.Extra []byte FileHeader.Flags uint16 Method is the compression method. If zero, Store is used. Modified is the modified time of the file. When reading, an extended timestamp is preferred over the legacy MS-DOS date field, and the offset between the times is used as the timezone. If only the MS-DOS date is present, the timezone is assumed to be UTC. When writing, an extended timestamp (which is timezone-agnostic) is always emitted. The legacy MS-DOS date field is encoded according to the location of the Modified time. ModifiedDate is an MS-DOS-encoded date. Deprecated: Use Modified instead. ModifiedTime is an MS-DOS-encoded time. Deprecated: Use Modified instead. Name is the name of the file. It must be a relative path, not start with a drive letter (such as "C:"), and must use forward slashes instead of back slashes. A trailing slash indicates that this file is a directory and should have no data. NonUTF8 indicates that Name and Comment are not encoded in UTF-8. By specification, the only other encoding permitted should be CP-437, but historically many ZIP readers interpret Name and Comment as whatever the system's local character encoding happens to be. This flag should only be set if the user intends to encode a non-portable ZIP file for a specific localized region. Otherwise, the Writer automatically sets the ZIP format's UTF-8 flag for valid UTF-8 strings. FileHeader.ReaderVersion uint16 UncompressedSize is the compressed size of the file in bytes. If either the uncompressed or compressed size of the file does not fit in 32 bits, CompressedSize is set to ^uint32(0). Deprecated: Use UncompressedSize64 instead. UncompressedSize64 is the uncompressed size of the file in bytes. 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. FileInfo returns an fs.FileInfo for the [FileHeader]. ModTime returns the modification time in UTC using the legacy [ModifiedDate] and [ModifiedTime] fields. Deprecated: Use [Modified] instead. Mode returns the permission and mode bits for the [FileHeader]. Open returns a [ReadCloser] that provides access to the [File]'s contents. Multiple files may be read concurrently. OpenRaw returns a [Reader] that provides access to the [File]'s contents without decompression. SetModTime sets the [Modified], [ModifiedTime], and [ModifiedDate] fields to the given time in UTC. Deprecated: Use [Modified] instead. SetMode changes the permission and mode bits for the [FileHeader]. func (*Writer).Copy(f *File) error
FileHeader describes a file within a ZIP file. See the [ZIP specification] for details. CRC32 is the CRC32 checksum of the file content. Comment is any arbitrary user-defined string shorter than 64KiB. CompressedSize is the compressed size of the file in bytes. If either the uncompressed or compressed size of the file does not fit in 32 bits, CompressedSize is set to ^uint32(0). Deprecated: Use CompressedSize64 instead. CompressedSize64 is the compressed size of the file in bytes. CreatorVersion uint16 // Meaning depends on CreatorVersion Extra []byte Flags uint16 Method is the compression method. If zero, Store is used. Modified is the modified time of the file. When reading, an extended timestamp is preferred over the legacy MS-DOS date field, and the offset between the times is used as the timezone. If only the MS-DOS date is present, the timezone is assumed to be UTC. When writing, an extended timestamp (which is timezone-agnostic) is always emitted. The legacy MS-DOS date field is encoded according to the location of the Modified time. ModifiedDate is an MS-DOS-encoded date. Deprecated: Use Modified instead. ModifiedTime is an MS-DOS-encoded time. Deprecated: Use Modified instead. Name is the name of the file. It must be a relative path, not start with a drive letter (such as "C:"), and must use forward slashes instead of back slashes. A trailing slash indicates that this file is a directory and should have no data. NonUTF8 indicates that Name and Comment are not encoded in UTF-8. By specification, the only other encoding permitted should be CP-437, but historically many ZIP readers interpret Name and Comment as whatever the system's local character encoding happens to be. This flag should only be set if the user intends to encode a non-portable ZIP file for a specific localized region. Otherwise, the Writer automatically sets the ZIP format's UTF-8 flag for valid UTF-8 strings. ReaderVersion uint16 UncompressedSize is the compressed size of the file in bytes. If either the uncompressed or compressed size of the file does not fit in 32 bits, CompressedSize is set to ^uint32(0). Deprecated: Use UncompressedSize64 instead. UncompressedSize64 is the uncompressed size of the file in bytes. FileInfo returns an fs.FileInfo for the [FileHeader]. ModTime returns the modification time in UTC using the legacy [ModifiedDate] and [ModifiedTime] fields. Deprecated: Use [Modified] instead. Mode returns the permission and mode bits for the [FileHeader]. SetModTime sets the [Modified], [ModifiedTime], and [ModifiedDate] fields to the given time in UTC. Deprecated: Use [Modified] instead. SetMode changes the permission and mode bits for the [FileHeader]. func FileInfoHeader(fi fs.FileInfo) (*FileHeader, error) func (*Writer).CreateHeader(fh *FileHeader) (io.Writer, error) func (*Writer).CreateRaw(fh *FileHeader) (io.Writer, error)
A ReadCloser is a [Reader] that must be closed when no longer needed. Reader Reader Reader.Comment string Reader.File []*File Close closes the Zip file, rendering it unusable for I/O. Open 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. 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. *ReadCloser : io.Closer *ReadCloser : io/fs.FS func OpenReader(name string) (*ReadCloser, error)
A Reader serves content from a ZIP archive. Comment string File []*File Open 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. 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. *Reader : io/fs.FS func NewReader(r io.ReaderAt, size int64) (*Reader, error)
Writer implements a zip file 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. Close finishes writing the zip file by writing the central directory. It does not close the underlying writer. Copy copies the file f (obtained from a [Reader]) into w. It copies the raw form directly bypassing decompression, compression, and validation. Create 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. The file's contents must be written to the [io.Writer] before the next call to [Writer.Create], [Writer.CreateHeader], or [Writer.Close]. 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]. 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. Flush flushes any buffered data to the underlying writer. Calling Flush is not normally necessary; calling Close is sufficient. 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. SetComment sets the end-of-central-directory comment field. It can only be called before [Writer.Close]. 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. *Writer : io.Closer func NewWriter(w io.Writer) *Writer
Package-Level Functions (total 6)
FileInfoHeader 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.
NewReader 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.
NewWriter returns a new [Writer] writing a zip file to w.
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.
RegisterCompressor registers custom compressors for a specified method ID. The common methods [Store] and [Deflate] are built in.
RegisterDecompressor allows custom decompressors for a specified method ID. The common methods [Store] and [Deflate] are built in.
Package-Level Variables (total 4)
Package-Level Constants (total 2)
Compression methods.
Compression methods.