Hello.
I’m currently developing software with Zig 0.15.2 that needs to extract a tar file compressed with zstandard and then obtain a list of the extracted files or directories.
How can I accomplish this using Zig’s standard library?
I’ve found that std.tar and std.compress.zstd.Decompress exist and looked through the standard library, but I have no idea how to use them.
This is also my first time asking a question here, so I’m not even sure if I’m formatting this correctly. Thank you in advance.
#How to extract Zstandard-compressed tar files using Zig stdlib (0.15.2)
atomic rain
sullen ether
Hello.
I’m currently developing software with Zig 0.15.2 that needs to extract a...
Following the docs:
https://ziglang.org/documentation/master/std/#std.compress.zstd.Decompress
https://ziglang.org/documentation/master/std/#std.tar.Iterator
I assume something like this:
const compressed_reader: *std.Io.Reader = ...
var zstd_stream = std.compress.zstd.Decompress.init(compressed_reader, &.{}, .{}); // optional buffering
const uncompressed_reader = &zstd_stream.reader;
var tar_stream = std.tar.Iterator.init(uncompressed_reader, .{});
while (try tar_stream.next()) |entry| {
switch (entry.kind) {
.directory => {}, // handle as you wish
.sym_link => {}, // handle as you wish
.file => { // example handling
var file = try std.fs.cwd().openFile(entry.name, .{});
defer file.close();
var file_writer = file.writer(&.{}); // optional buffering
try tar_stream.streamRemaining(entry, &file_writer.interface);
try file_writer.flush();
},
}
}
Thank you! I’ll try it out right away.
granite monolith
Following the docs:
<https://ziglang.org/documentation/master/std/#std.compress....
the buffers are not optional in the way that this code implies. A zero-length buffer for the zstd.Decompress buffer puts it in "direct" mode which places heavy constraints on the rest of the chain, see these links for context:
for this particular example you'd probably need a buffer of size std.compress.zstd.default_window_len + std.compress.zstd.block_size_max for zstd.Decompress
atomic rain
for this particular example you'd probably need a buffer of size `std.compress.z...
Thank you! I was just about to ask that!
By the way, sorry if this is a beginner question, but how can I get a std.io.Reader from a std.fs.File?
Should I use std.fs.File.Reader.interface for that?
velvet shore