NSPRE

A single header c++ library for reading and writing Neversoft pre/prx files.

Including the library

As a single header library, the declarations and definitions in this library are in the same file. To avoid violating the one definition rule you need to write #define NSPRE_IMPL before #include "nspre.hpp" in only one source file. This will put the definitions for all the classes and functions in that source file. You can #include "nspre.hpp" as usual in any other file.

ns-unpack and ns-pack

These are example programs to demonstrate basic use of the library.

Build using cmake:

cd nspre
mkdir build
cmake -S . -B build/
cmake --build build/

Programs can be found at build/pack/ns-pack and build/unpack/ns-unpack.

Documentation

Classes

nspre::Reader

A class representing a successfully opened pre/prx file.

Reader::Reader(const std::filesystem::path& path)

Constructor for the Reader class.

path: Path to the pre/prx file to be read

Reader::Reader()

Constructor for the Reader class. You must use Reader::open() before you can do anything.

int Reader::open(const std::filesystem::path& path)

Open a pre/prx file. Equivalent to the Reader(const std::filesystem::path& path) constructor.

path: Path to the pre/prx file to be read

void Reader::close()

Reset a Reader to an uninitialized state.

std::vector<Subfile>& Reader::files()

Returns the Subfiles from a successfully opened pre/prx file. Will be an empty vector if opening the file failed.

int Reader::size()

Returns the total file size as recorded in the file.

std::vector<char> Reader::header()

Returns a vector containing the raw 12 byte header of the file.

int Reader::error()

Returns the error state of the reader. Anything other than 0 indicates failure to open the file.

nspre::Reader::Subfile

A subfile within the pre/prx file.

std::string& Reader::Subfile::prepath()

Returns a reference to the internal path recorded in the Subfile.

std::string Reader::Subfile::filename()

Returns the filename from the internal path.

int Reader::Subfile::cmp_size()

Returns the compressed size of the file if it is compressed. Returns 0 if it is uncompressed.

int Reader::Subfile::size()

Returns the actual size of the file.

std::vector<char> Reader::Subfile::subheader()

Returns a vector containing the raw 16 byte header of the Subfile.

int Reader::Subfile::offset()

Returns the offset to the start of the Subfile data.

int Reader::Subfile::extract(char* data_out)

Decompress the file if necessary and copy it to a char array. Size of the array must be greater than or equal to the value returned by size(). Returns 0 on success.

int Reader::Subfile::extract(std::vector<char>& data_out)

Decompress the file if necessary and copy it to a char vector. Vector will automatically be resized to appropriate size and overwritten. Returns 0 on success.

int Reader::Subfile::extract(const std::filesystem::path& path)

Decompress the file if necessary and write it to a file. Returns 0 on success.

nspre::Subfile

Represents an external file and its associated internal path to be included in a pre file.

Subfile::Subfile(const std::filesystem::path& i_source, const std::string& i_prepath)

Constructor for the Subfile class.

i_source: Path to the file on disk

i_prepath: Internal path to be recorded in Subfile

std::string& Subfile::prepath()

Returns a reference to the internal path recorded in the Subfile.

std::string Subfile::filename()

Returns the filename from the internal path.

Subfile::source

The path to the file on disk.

Functions

int write(Subfile* subfiles, size_t count, const std::filesystem::path& path)

Writes a list of files to a pre file. Can't perform compression. Returns 0 on success.

subfiles: Pointer to an array of Subfiles

count: Number of Subfiles

path: File to write to

int write(std::vector<Subfile>& subfiles, const std::filesystem::path& path)

Writes a list of files to a pre file. Can't perform compression. Returns 0 on success.

subfiles: Vector of Subfiles

path: File to write to