Provides utilities for reading and extracting TAR and TAR.GZ archives. More...

Classes
struct	FileReader
	Reader implementation for uncompressed files using std::ifstream. More...
struct	GzReader
	Reader implementation for gzip-compressed files using zlib's gzFile interface. More...
struct	Reader
	Abstract base class for sequential byte stream reading. More...
struct	TarHdr
	Represents the raw 512-byte POSIX TAR header structure (USTAR format). More...

Static Public Member Functions
static bool	all_zero (const u8 *p, size_t n)
	Checks whether all bytes in a buffer are zero.
static void	apply_mode (const fs::path &p, u64 mode)
	Applies POSIX file permissions to the given path based on a TAR mode value.
static void	apply_mtime (const fs::path &p, u64 mtime)
	Sets the last modification time of a file to the given Unix timestamp.
static int	Extract (const File &src, const File &dest)
	Extracts all entries from a TAR or TAR.GZ archive to a destination directory.
static std::string	hdr_name (const TarHdr &h)
	Extracts the full file name from a TAR header, combining prefix and name fields.
static u64	parse_octal (const char *p, size_t n)
	Parses an octal number from a TAR header field string.
static bool	read_block (Reader &r, u8 *buf)
	Reads a single 512-byte block from the reader.
static std::string	read_pax_string (const std::string &rec)
	Returns a PAX extended attribute record string as-is.
static bool	skip_bytes (Reader &r, u64 n, std::vector< u8 > &tmp)
	Skips over a specified number of bytes in the reader stream.
static bool	starts_with (const fs::path &a, const fs::path &base)
	Checks whether path a starts with the given base path using weakly canonical forms.
static u64	tar_checksum (const u8 *h)
	Computes the TAR checksum for a 512-byte header block.
static bool	valid_hdr (const u8 *blk)
	Validates a 512-byte TAR header block by verifying its checksum.

Detailed Description

Provides utilities for reading and extracting TAR and TAR.GZ archives.

Definition at line 18 of file TarReader.h.

Member Function Documentation

◆ all_zero()

bool TAR::all_zero	(	const u8 *	p,
		size_t	n )

inlinestatic

Checks whether all bytes in a buffer are zero.

Parameters

[in]	p	Pointer to the buffer.
[in]	n	Number of bytes to check.

Returns: True if all bytes are zero, false otherwise.

Definition at line 138 of file TarReader.h.

Referenced by Extract().

◆ apply_mode()

void TAR::apply_mode	(	const fs::path &	p,
		u64	mode )

inlinestatic

Applies POSIX file permissions to the given path based on a TAR mode value.

Parameters

[in]	p	The filesystem path to apply permissions to.
[in]	mode	The POSIX mode bits to apply.

Definition at line 240 of file TarReader.h.

Referenced by Extract().

◆ apply_mtime()

void TAR::apply_mtime	(	const fs::path &	p,
		u64	mtime )

inlinestatic

Sets the last modification time of a file to the given Unix timestamp.

Parameters

[in]	p	The filesystem path to update.
[in]	mtime	The modification time as seconds since Unix epoch.

Definition at line 260 of file TarReader.h.

Referenced by Extract().

◆ Extract()

int TAR::Extract	(	const File &	src,
		const File &	dest )

inlinestatic

Extracts all entries from a TAR or TAR.GZ archive to a destination directory.

Supports regular files, directories, symbolic links, hard links, PAX extended headers, and GNU long name/link extensions. Automatically detects gzip compression by inspecting the file signature.

Parameters

[in]	src	The source TAR or TAR.GZ archive file.
[in]	dest	The destination directory to extract into.

Returns: 0 on success, or a negative error code on failure: -1 if the destination directory could not be created, -2 if the source file could not be opened, -3 if the reader failed to initialize, -4 if a block read failed, -5 if a header checksum was invalid, -6 through -16 for various extraction errors.

Definition at line 312 of file TarReader.h.

References all_zero(), apply_mode(), apply_mtime(), String::c_str(), TAR::FileReader::f, TAR::GzReader::g, hdr_name(), TAR::TarHdr::linkname, TAR::TarHdr::magic, TAR::TarHdr::mode, TAR::TarHdr::mtime, name, parse_octal(), read_block(), TAR::TarHdr::size, skip_bytes(), starts_with(), type, TAR::TarHdr::typeflag, and valid_hdr().

◆ hdr_name()

std::string TAR::hdr_name ( const TarHdr & h )

inlinestatic

Extracts the full file name from a TAR header, combining prefix and name fields.

Parameters

[in] h The TAR header to extract the name from.

Returns: The full entry name as a string.

Definition at line 202 of file TarReader.h.

References TAR::TarHdr::name, and TAR::TarHdr::prefix.

Referenced by Extract().

◆ parse_octal()

u64 TAR::parse_octal	(	const char *	p,
		size_t	n )

inlinestatic

Parses an octal number from a TAR header field string.

Parameters

[in]	p	Pointer to the octal string.
[in]	n	Maximum number of characters to parse.

Returns: The parsed unsigned 64-bit integer value.

Definition at line 149 of file TarReader.h.

Referenced by Extract(), and valid_hdr().

◆ read_block()

bool TAR::read_block	(	Reader &	r,
		u8 *	buf )

inlinestatic

Reads a single 512-byte block from the reader.

Parameters

[in]	r	The reader to read from.
[in]	buf	Buffer to store the 512-byte block.

Returns: True if the block was successfully read, false otherwise.

Definition at line 273 of file TarReader.h.

References TAR::Reader::read_exact().

Referenced by Extract().

◆ read_pax_string()

std::string TAR::read_pax_string ( const std::string & rec )

inlinestatic

Returns a PAX extended attribute record string as-is.

Parameters

[in] rec The PAX record string.

Returns: The unmodified record string.

Definition at line 231 of file TarReader.h.

◆ skip_bytes()

bool TAR::skip_bytes	(	Reader &	r,
		u64	n,
		std::vector< u8 > &	tmp )

inlinestatic

Skips over a specified number of bytes in the reader stream.

Parameters

[in]	r	The reader to skip bytes from.
[in]	n	Number of bytes to skip.
[in]	tmp	Temporary buffer used for reading and discarding data.

Returns: True if all bytes were successfully skipped, false otherwise.

Definition at line 284 of file TarReader.h.

References TAR::Reader::read_exact().

Referenced by Extract().

◆ starts_with()

bool TAR::starts_with	(	const fs::path &	a,
		const fs::path &	base )

inlinestatic

Checks whether path a starts with the given base path using weakly canonical forms.

Parameters

[in]	a	The path to check.
[in]	base	The base path to compare against.

Returns: True if a begins with base, false otherwise.

Definition at line 122 of file TarReader.h.

Referenced by Extract().

◆ tar_checksum()

u64 TAR::tar_checksum ( const u8 * h )

inlinestatic

Computes the TAR checksum for a 512-byte header block.

Parameters

[in] h Pointer to the 512-byte header block.

Returns: The computed checksum value.

Definition at line 165 of file TarReader.h.

Referenced by valid_hdr().

◆ valid_hdr()

bool TAR::valid_hdr ( const u8 * blk )

inlinestatic

Validates a 512-byte TAR header block by verifying its checksum.

Parameters

[in] blk Pointer to the 512-byte header block.

Returns: True if the checksum is valid, false otherwise.

Definition at line 220 of file TarReader.h.

References TAR::TarHdr::chksum, parse_octal(), and tar_checksum().

Referenced by Extract().

The documentation for this class was generated from the following file:

Base/Headers/TarReader.h

Classes

Static Public Member Functions

Detailed Description

Member Function Documentation

◆ all_zero()

◆ apply_mode()

◆ apply_mtime()

◆ Extract()

◆ hdr_name()

◆ parse_octal()

◆ read_block()

◆ read_pax_string()

◆ skip_bytes()

◆ starts_with()

◆ tar_checksum()

◆ valid_hdr()