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no-rustdoc
Philipp Schuster 2021-10-04 11:00:03 +02:00
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# top-most EditorConfig file
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# Unix-style newlines with a newline ending every file
[*]
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indent_size = 4
trim_trailing_whitespace = true

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/target

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[package]
name = "tar-no-std"
description = """
Library to read Tar archives (by GNU Tar) in `no_std` contexts with zero allocations.
The crate is simple and only supports reading of "basic" archives, therefore no extensions, such
as GNU Longname. The maximum supported file size is 100 characters including the NULL-byte.
"""
version = "0.1.0"
edition = "2018"
keywords = ["tar", "tarball", "archive"]
categories = ["data-structures", "no-std", "parser-implementations"]
readme = "README.md"
license = "MIT"
homepage = "https://github.com/phip1611/tar-no-std"
repository = "https://github.com/phip1611/tar-no-std"
documentation = "https://docs.rs/tar-no-std"
[dependencies]
bitflags = "1.3"
arrayvec = { version = "0.7", default-features = false }
log = { version = "0.4", default-features = false }
[dev-dependencies]
env_logger = "0.9"

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# `tar-no_std` - Parse Tar Archives (Tarballs)
_Due to historical reasons, there are several formats of tar archives. All of them are based on the same principles,
but have some subtle differences that often make them incompatible with each other._ [[0]]
Library to read Tar archives (by GNU Tar) in `no_std` contexts with zero allocations. If you have a standard
environment and need full feature support, I recommend the use of <https://crates.io/crates/tar> instead.
The crate is simple and only supports reading of "basic" archives, therefore no extensions, such
as *GNU Longname*. The maximum supported file name length is 100 characters including the NULL-byte.
The maximum supported file size is 8GiB. Also, directories are not supported yet but only flat
collections of files.
This library is useful, if you write a kernel or a similar low-level application, which needs
"a bunch of files" from an archive ("init ramdisk"). The Tar file could for example come
as a Multiboot2 boot module provided by the bootloader.
This crate focuses on extracting files from uncompressed Tar archives created with default options by **GNU Tar**.
GNU Extensions such as sparse files, incremental archives, and long filename extension are not supported yet.
[This link](https://www.gnu.org/software/tar/manual/html_section/Formats.html) gives a good overview over possible
archive formats and their limitations.
## Compression
If your tar file is compressed, e.g. bei `gzip`, you need to uncompress the bytes first (e.g. by a *deflate* algorithm),
before
## MSRV
The MSRV is 1.51.0 stable.
[0]: https://www.gnu.org/software/tar/manual/html_section/Formats.html

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/*
MIT License
Copyright (c) 2021 Philipp Schuster
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
*/
use tar_no_std::TarArchive;
fn main() {
// log: not mandatory
std::env::set_var("RUST_LOG", "trace");
env_logger::init();
// also works in no_std environment
let archive = include_bytes!("../tests/gnu_tar_default.tar");
let archive = TarArchive::new(archive);
let entries = archive.entries().collect::<Vec<_>>();
println!("{:#?}", entries);
}

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/*
MIT License
Copyright (c) 2021 Philipp Schuster
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
*/
//! Module for [`TarArchive`].
use crate::header::PosixHeader;
use crate::{TypeFlag, BLOCKSIZE};
use arrayvec::ArrayString;
use core::fmt::{Debug, Formatter};
use core::ptr;
use core::str::FromStr;
/// Describes an entry in a archive.
/// Currently only supports files but no directories.
pub struct ArchiveEntry<'a> {
filename: ArrayString<100>,
data: &'a [u8],
size: usize,
}
#[allow(unused)]
impl<'a> ArchiveEntry<'a> {
pub fn new(filename: ArrayString<100>, data: &'a [u8]) -> Self {
ArchiveEntry {
filename,
data,
size: data.len(),
}
}
/// Filename of the entry. Max 99 characters.
pub fn filename(&self) -> ArrayString<100> {
self.filename
}
/// Data of the file.
pub fn data(&self) -> &'a [u8] {
self.data
}
/// Filesize in bytes.
pub fn size(&self) -> usize {
self.size
}
}
impl<'a> Debug for ArchiveEntry<'a> {
fn fmt(&self, f: &mut Formatter<'_>) -> core::fmt::Result {
f.debug_struct("ArchiveEntry")
.field("filename", &self.filename().as_str())
.field("size", &self.size())
.field("data", &"<bytes>")
.finish()
}
}
/// Wrapper type around the bytes, which represents an archive.
#[derive(Debug)]
pub struct TarArchive<'a> {
data: &'a [u8],
}
#[allow(unused)]
impl<'a> TarArchive<'a> {
/// Interprets the provided byte array as Tar archive.
pub fn new(data: &'a [u8]) -> Self {
assert_eq!(
data.len() % BLOCKSIZE,
0,
"data must be a multiple of BLOCKSIZE={}",
BLOCKSIZE
);
Self { data }
}
/// Iterates over all entries of the TAR Archive.
/// Returns items of type [`ArchiveEntry`].
pub fn entries(&self) -> ArchiveIterator {
ArchiveIterator::new(self)
}
}
/// Iterator over the files. Each iteration step starts
/// at the next Tar header entry.
#[derive(Debug)]
pub struct ArchiveIterator<'a> {
archive: &'a TarArchive<'a>,
block_index: usize,
}
impl<'a> ArchiveIterator<'a> {
pub fn new(archive: &'a TarArchive<'a>) -> Self {
Self {
archive,
block_index: 0,
}
}
/// Returns a pointer to the next Header.
fn next_hdr(&self, block_index: usize) -> *const PosixHeader {
let hdr_ptr = &self.archive.data[block_index * BLOCKSIZE];
let hdr_ptr = hdr_ptr as *const u8;
hdr_ptr as *const PosixHeader
}
}
impl<'a> Iterator for ArchiveIterator<'a> {
type Item = ArchiveEntry<'a>;
fn next(&mut self) -> Option<Self::Item> {
if self.block_index * BLOCKSIZE >= self.archive.data.len() {
log::warn!("Reached end of Tar archive data without finding zero/end blocks!");
return None;
}
let hdr = self.next_hdr(self.block_index);
let hdr = unsafe { ptr::read(hdr) };
// check if we found end of archive
if hdr.is_zero_block() {
let next_hdr = unsafe { ptr::read(self.next_hdr(self.block_index + 1)) };
if next_hdr.is_zero_block() {
// gracefully terminated Archive
log::debug!("End of Tar archive with two zero blocks!");
} else {
log::warn!("Zero block found at end of Tar archive, but only one instead of two!");
}
// end of archive
return None;
}
if hdr.typeflag != TypeFlag::AREGTYPE && hdr.typeflag != TypeFlag::REGTYPE {
log::warn!(
"Found entry of type={:?}, but only files are supported",
hdr.typeflag
);
return None;
}
// fetch data of file from next block(s)
let block_count = hdr.payload_block_count();
let i_begin = self.block_index * BLOCKSIZE;
let i_end = i_begin + block_count * BLOCKSIZE;
debug_assert!(i_end <= self.archive.data.len(), "index ouf of range!");
// +1: hdr itself + data blocks
self.block_index += block_count + 1;
let file_block_bytes = &self.archive.data[i_begin..i_end];
let file_bytes = &file_block_bytes[0..hdr.size.val()];
Some(ArchiveEntry::new(
ArrayString::from_str(hdr.name.as_string().as_str()).unwrap(),
file_bytes,
))
}
}
#[cfg(test)]
mod tests {
use super::*;
use std::vec::Vec;
#[test]
fn test_archive_list() {
let archive = TarArchive::new(include_bytes!("../tests/gnu_tar_default.tar"));
let entries = archive.entries().collect::<Vec<_>>();
println!("{:#?}", entries);
}
#[test]
fn test_archive_entries() {
let archive = TarArchive::new(include_bytes!("../tests/gnu_tar_default.tar"));
let entries = archive.entries().collect::<Vec<_>>();
assert_archive_content(&entries);
let archive = TarArchive::new(include_bytes!("../tests/gnu_tar_gnu.tar"));
let entries = archive.entries().collect::<Vec<_>>();
assert_archive_content(&entries);
let archive = TarArchive::new(include_bytes!("../tests/gnu_tar_oldgnu.tar"));
let entries = archive.entries().collect::<Vec<_>>();
assert_archive_content(&entries);
// UNSUPPORTED. Uses extensions.
/*let archive = TarArchive::new(include_bytes!("../tests/gnu_tar_pax.tar"));
let entries = archive.entries().collect::<Vec<_>>();
assert_archive_content(&entries);*/
// UNSUPPORTED. Uses extensions.
/*let archive = TarArchive::new(include_bytes!("../tests/gnu_tar_posix.tar"));
let entries = archive.entries().collect::<Vec<_>>();
assert_archive_content(&entries);*/
let archive = TarArchive::new(include_bytes!("../tests/gnu_tar_ustar.tar"));
let entries = archive.entries().collect::<Vec<_>>();
assert_archive_content(&entries);
let archive = TarArchive::new(include_bytes!("../tests/gnu_tar_v7.tar"));
let entries = archive.entries().collect::<Vec<_>>();
assert_archive_content(&entries);
}
fn assert_archive_content(entries: &[ArchiveEntry]) {
assert_eq!(entries.len(), 3);
// order in that I stored the files into the archive
assert_eq!(entries[0].filename().as_str(), "bye_world_513b.txt");
assert_eq!(entries[0].size(), 513);
assert_eq!(entries[0].data().len(), 513);
assert_eq!(entries[1].filename().as_str(), "hello_world_513b.txt");
assert_eq!(entries[1].size(), 513);
assert_eq!(entries[1].data().len(), 513);
assert_eq!(entries[2].filename().as_str(), "hello_world.txt");
assert_eq!(entries[2].size(), 12);
assert_eq!(entries[2].data().len(), 12);
}
}

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/*
MIT License
Copyright (c) 2021 Philipp Schuster
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
*/
//! TAR header definition taken from <https://www.gnu.org/software/tar/manual/html_node/Standard.html>.
//! A Tar-archive is a collection of 512-byte sized blocks. Unfortunately there are several
//! TAR-like archive specifications. An Overview can be found here:
//! <https://www.gnu.org/software/tar/manual/html_node/Formats.html#Formats>
//!
//! This library focuses on extracting files from the GNU Tar format.
#![allow(non_upper_case_globals)]
use crate::BLOCKSIZE;
use arrayvec::ArrayString;
use core::fmt::{Debug, Formatter};
/// The file size is encoded as octal ASCII number inside a Tar header.
#[derive(Copy, Clone)]
#[repr(transparent)]
pub struct Size(StaticCString<12>);
impl Size {
/// Returns the octal ASCII number as actual size in bytes.
pub fn val(&self) -> usize {
usize::from_str_radix(self.0.as_string().as_str(), 8).unwrap()
}
}
impl Debug for Size {
fn fmt(&self, f: &mut Formatter<'_>) -> core::fmt::Result {
let mut debug = f.debug_tuple("Size");
debug.field(&self.val());
debug.finish()
}
}
#[derive(Copy, Clone)]
#[repr(transparent)]
pub struct Mode(StaticCString<8>);
impl Mode {
pub fn to_flags(self) -> ModeFlags {
let octal_number_str = self.0.as_string();
let bits = u64::from_str_radix(octal_number_str.as_str(), 8).unwrap();
ModeFlags::from_bits(bits).unwrap()
}
}
impl Debug for Mode {
fn fmt(&self, f: &mut Formatter<'_>) -> core::fmt::Result {
let mut debug = f.debug_tuple("Mode");
debug.field(&self.to_flags());
debug.finish()
}
}
/// A C-String that is stored in a static array. All unused
/// chars must be a NULL-byte.
#[derive(Copy, Clone)]
#[repr(transparent)]
pub struct StaticCString<const N: usize>([u8; N]);
#[allow(unused)]
impl<const N: usize> StaticCString<N> {
/// Constructor.
fn new(bytes: [u8; N]) -> Self {
Self(bytes)
}
/// Returns the length of the string without NULL-byte.
pub fn len(&self) -> usize {
// not as efficient as it could be but negligible
self.as_string().len()
}
/// Returns a string without null bytes.
pub fn as_string(&self) -> ArrayString<N> {
let mut string = ArrayString::new();
// copy all bytes (=ASCII) into string
self.0
.clone()
.iter()
// remove all zero bytes; there is always one
// zero byte at the end. Furtherore, the other
// unused bytes are also zero, but not part of the
// string.
.filter(|x| **x != 0)
.for_each(|b| string.push(*b as char));
string
}
}
impl<const N: usize> Debug for StaticCString<N> {
fn fmt(&self, f: &mut Formatter<'_>) -> core::fmt::Result {
let mut debug = f.debug_tuple("Name");
let str = self.as_string();
if str.len() == 0 {
debug.field(&"<empty>");
} else {
debug.field(&str);
}
debug.finish()
}
}
/// Header of the TAR format as specified by POSIX (POSIX 1003.1-1990.
/// "New" (version?) GNU Tar versions use this archive format by default.
/// (<https://www.gnu.org/software/tar/manual/html_node/Formats.html#Formats>).
///
/// Each file is started by such a header, that describes the size and
/// the file name. After that, the file content stands in chunks of 512 bytes.
/// The number of bytes can be derived from the file size.
///
/// This is also mostly compatible with the "Ustar"-header and the "GNU format".
/// Because this library only needs to fetch data and filename, we don't need
/// further checks.
#[derive(Debug, Copy, Clone)]
#[repr(C, packed)]
pub struct PosixHeader {
/// Name. There is always a null byte, therefore
/// the max len is 99.
pub name: StaticCString<100>,
pub mode: Mode,
pub uid: [u8; 8],
pub gid: [u8; 8],
// confusing; size is stored as ASCII string
pub size: Size,
pub mtime: [u8; 12],
pub cksum: [u8; 8],
pub typeflag: TypeFlag,
/// Name. There is always a null byte, therefore
/// the max len is 99.
pub linkname: StaticCString<100>,
pub magic: StaticCString<6>,
pub version: StaticCString<2>,
/// Username. There is always a null byte, therefore
/// the max len is N-1.
pub uname: StaticCString<32>,
/// Groupname. There is always a null byte, therefore
/// the max len is N-1.
pub gname: StaticCString<32>,
pub dev_major: [u8; 8],
pub dev_minor: [u8; 8],
/// There is always a null byte, therefore
/// the max len is N-1.
pub prefix: StaticCString<155>,
// padding => to BLOCKSIZE bytes
pub _pad: [u8; 12],
}
impl PosixHeader {
/// Returns the number of blocks that are required to
/// read the whole file content.
pub fn payload_block_count(&self) -> usize {
let div = self.size.val() / BLOCKSIZE;
let modulo = self.size.val() % BLOCKSIZE;
if modulo > 0 {
(div + 1) as usize
} else {
div as usize
}
}
/// A Tar archive is terminated, if a end-of-archive entry, which consists of two 512 blocks
/// of zero bytes, is found.
pub fn is_zero_block(&self) -> bool {
let ptr = self as *const Self as *const u8;
let self_bytes = unsafe { core::slice::from_raw_parts(ptr, BLOCKSIZE) };
self_bytes.iter().filter(|x| **x == 0).count() == BLOCKSIZE
}
}
#[derive(Debug, Copy, Clone, PartialEq)]
#[repr(u8)]
#[allow(unused)]
pub enum TypeFlag {
/// Represents a regular file. In order to be compatible with older versions of tar, a typeflag
/// value of AREGTYPE should be silently recognized as a regular file. New archives should be
/// created using REGTYPE. Also, for backward compatibility, tar treats a regular file whose
/// name ends with a slash as a directory.
REGTYPE = b'0',
/// Represents a regular file. In order to be compatible with older versions of tar, a typeflag
/// value of AREGTYPE should be silently recognized as a regular file. New archives should be
/// created using REGTYPE. Also, for backward compatibility, tar treats a regular file whose
/// name ends with a slash as a directory.
AREGTYPE = b'\0',
/// This flag represents a file linked to another file, of any type, previously archived. Such
/// files are identified in Unix by each file having the same device and inode number. The
/// linked-to name is specified in the linkname field with a trailing null.
LINK = 1,
/// This represents a symbolic link to another file. The linked-to name is specified in the
/// linkname field with a trailing null.
SYMTYPE = 2,
/// Represents character special files and block special files respectively. In this case the
/// devmajor and devminor fields will contain the major and minor device numbers respectively.
/// Operating systems may map the device specifications to their own local specification, or
/// may ignore the entry.
CHRTYPE = 3,
/// Represents character special files and block special files respectively. In this case the
/// devmajor and devminor fields will contain the major and minor device numbers respectively.
/// Operating systems may map the device specifications to their own local specification, or
/// may ignore the entry.
BLKTYPE = 4,
/// This flag specifies a directory or sub-directory. The directory name in the name field
/// should end with a slash. On systems where disk allocation is performed on a directory
/// basis, the size field will contain the maximum number of bytes (which may be rounded to
/// the nearest disk block allocation unit) which the directory may hold. A size field of zero
/// indicates no such limiting. Systems which do not support limiting in this manner should
/// ignore the size field.
DIRTYPE = 5,
/// This specifies a FIFO special file. Note that the archiving of a FIFO file archives the
/// existence of this file and not its contents.
FIFOTYPE = 6,
/// This specifies a contiguous file, which is the same as a normal file except that, in
/// operating systems which support it, all its space is allocated contiguously on the disk.
/// Operating systems which do not allow contiguous allocation should silently treat this type
/// as a normal file.
CONTTYPE = 7,
/// Extended header referring to the next file in the archive
XHDTYPE = b'x',
/// Global extended header
XGLTYPE = b'g',
}
bitflags::bitflags! {
/// UNIX file permissions on octal format.
pub struct ModeFlags: u64 {
/// Set UID on execution.
const SetUID = 0o4000;
/// Set GID on execution.
const SetGID = 0o2000;
/// Reserved.
const TSVTX = 0o1000;
/// Owner read.
const OwnerRead = 0o400;
/// Owner write.
const OwnerWrite = 0o200;
/// Owner execute.
const OwnerExec = 0o100;
/// Group read.
const GroupRead = 0o040;
/// Group write.
const GroupWrite = 0o020;
/// Group execute.
const GroupExec = 0o010;
/// Others read.
const OthersRead = 0o004;
/// Others read.
const OthersWrite = 0o002;
/// Others execute.
const OthersExec = 0o001;
}
}
#[cfg(test)]
mod tests {
use crate::header::{PosixHeader, StaticCString, TypeFlag};
use crate::BLOCKSIZE;
use std::mem::size_of;
fn bytes_to_archive(bytes: &[u8]) -> PosixHeader {
let hdr = bytes.as_ptr() as *const PosixHeader;
unsafe { core::ptr::read(hdr) }
}
#[test]
fn test_display_header() {
let archive = bytes_to_archive(include_bytes!("../tests/gnu_tar_default.tar"));
println!("{:#?}'", archive);
}
#[test]
fn test_show_tar_header_magics() {
let archive = bytes_to_archive(include_bytes!("../tests/gnu_tar_default.tar"));
println!(
"default: magic='{:?}', version='{:?}'",
archive.magic, archive.version
);
let archive = bytes_to_archive(include_bytes!("../tests/gnu_tar_gnu.tar"));
println!(
"gnu: magic='{:?}', version='{:?}'",
archive.magic, archive.version
);
let archive = bytes_to_archive(include_bytes!("../tests/gnu_tar_oldgnu.tar"));
println!(
"oldgnu: magic='{:?}', version='{:?}'",
archive.magic, archive.version
);
let archive = bytes_to_archive(include_bytes!("../tests/gnu_tar_pax.tar"));
println!(
"pax: magic='{:?}', version='{:?}'",
archive.magic, archive.version
);
let archive = bytes_to_archive(include_bytes!("../tests/gnu_tar_posix.tar"));
println!(
"posix: magic='{:?}', version='{:?}'",
archive.magic, archive.version
);
let archive = bytes_to_archive(include_bytes!("../tests/gnu_tar_ustar.tar"));
println!(
"ustar: magic='{:?}', version='{:?}'",
archive.magic, archive.version
);
let archive = bytes_to_archive(include_bytes!("../tests/gnu_tar_v7.tar"));
println!(
"v7: magic='{:?}', version='{:?}'",
archive.magic, archive.version
);
}
#[test]
fn test_parse_tar_header_filename() {
let archive = bytes_to_archive(include_bytes!("../tests/gnu_tar_default.tar"));
assert_eq!(
archive.typeflag,
TypeFlag::REGTYPE,
"the first entry is a regular file!"
);
assert_eq!(archive.name.as_string().as_str(), "bye_world_513b.txt");
let archive = bytes_to_archive(include_bytes!("../tests/gnu_tar_gnu.tar"));
assert_eq!(
archive.typeflag,
TypeFlag::REGTYPE,
"the first entry is a regular file!"
);
assert_eq!(archive.name.as_string().as_str(), "bye_world_513b.txt");
let archive = bytes_to_archive(include_bytes!("../tests/gnu_tar_oldgnu.tar"));
assert_eq!(
archive.typeflag,
TypeFlag::REGTYPE,
"the first entry is a regular file!"
);
assert_eq!(archive.name.as_string().as_str(), "bye_world_513b.txt");
/* UNSUPPORTED YET. Uses extensions..
let archive = bytes_to_archive(include_bytes!("../tests/gnu_tar_pax.tar"));
assert_eq!(archive.typeflag, TypeFlag::REGTYPE, "the first entry is a regular file!");
assert_eq!(archive.name.as_string().as_str(), "bye_world_513b.txt"); */
/* UNSUPPORTED YET. Uses extensions.
let archive = bytes_to_archive(include_bytes!("../tests/gnu_tar_posix.tar"));
unsupported extension XHDTYPE assert_eq!(archive.typeflag, TypeFlag::REGTYPE, "the first entry is a regular file!");
assert_eq!(archive.name.as_string().as_str(), "bye_world_513b.txt"); */
let archive = bytes_to_archive(include_bytes!("../tests/gnu_tar_ustar.tar"));
assert_eq!(
archive.typeflag,
TypeFlag::REGTYPE,
"the first entry is a regular file!"
);
assert_eq!(archive.name.as_string().as_str(), "bye_world_513b.txt");
let archive = bytes_to_archive(include_bytes!("../tests/gnu_tar_v7.tar"));
// ARegType: legacy
assert_eq!(
archive.typeflag,
TypeFlag::AREGTYPE,
"the first entry is a regular file!"
);
assert_eq!(archive.name.as_string().as_str(), "bye_world_513b.txt");
}
#[test]
fn test_size() {
assert_eq!(BLOCKSIZE, size_of::<PosixHeader>());
}
#[test]
fn test_static_str() {
let str = StaticCString::new(*b"0000633\0");
assert_eq!(str.len(), 7);
assert_eq!(str.as_string().as_str(), "0000633");
}
}

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/*
MIT License
Copyright (c) 2021 Philipp Schuster
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
*/
//! Library to read Tar archives (by GNU Tar) in `no_std` contexts with zero allocations.
//! If you have a standard environment and need full feature support, I recommend the use of
//! <https://crates.io/crates/tar> instead.
//!
//! The crate is simple and only supports reading of "basic" archives, therefore no extensions, such
//! as GNU Longname. The maximum supported file name length is 100 characters including the NULL-byte.
//! The maximum supported file size is 8GiB. Also, directories are not supported yet but only flat
//! collections of files.
//!
//! This library is useful, if you write a kernel or a similar low-level application, which needs
//! "a bunch of files" from an archive ("init ram disk"). The Tar file could for example come
//! as a Multiboot2 boot module provided by the bootloader.
//!
//! This crate focuses on extracting files from uncompressed Tar archives created with default options by **GNU Tar**.
//! GNU Extensions such as sparse files, incremental archives, and long filename extension are not supported yet.
//! [This link](https://www.gnu.org/software/tar/manual/html_section/Formats.html) gives a good overview over possible
//! archive formats and their limitations.
#![cfg_attr(not(test), no_std)]
#[cfg_attr(test, macro_use)]
#[cfg(test)]
extern crate std;
/// Each Archive Entry (either Header or Data Block) is a block of 512 bytes.
const BLOCKSIZE: usize = 512;
mod archive;
mod header;
pub use archive::*;
pub use header::*;

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Hello World

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