Working with Tarballs

Decompress a tarball

Decompress (GzDecoder) andextract (Archive::unpack) all files from a compressed tarballnamedarchive.tar.gz located in the current working directoryto the same location.

use std::fs::File;use flate2::read::GzDecoder;use tar::Archive;fn main() -> Result<(), std::io::Error> {    let path = "archive.tar.gz";    let tar_gz = File::open(path)?;    let tar = GzDecoder::new(tar_gz);    let mut archive = Archive::new(tar);    archive.unpack(".")?;    Ok(())}

Compress a directory into tarball

Compress/var/log directory intoarchive.tar.gz.

Creates aFile wrapped inGzEncoderandtar::Builder.
Adds contents of/var/log directory recursively into the archiveunderbackup/logs path withBuilder::append_dir_all.GzEncoder is responsible for transparently compressing thedata prior to writing it intoarchive.tar.gz.

use std::fs::File;use flate2::Compression;use flate2::write::GzEncoder;fn main() -> Result<(), std::io::Error> {    let tar_gz = File::create("archive.tar.gz")?;    let enc = GzEncoder::new(tar_gz, Compression::default());    let mut tar = tar::Builder::new(enc);    tar.append_dir_all("backup/logs", "/var/log")?;    tar.finish()?;    Ok(())}

To add the contents without renaming them, an empty string can be used as the first argument ofBuilder::append_dir_all:

use std::fs::File;use flate2::Compression;use flate2::write::GzEncoder;fn main() -> Result<(), std::io::Error> {    let tar_gz = File::create("archive.tar.gz")?;    let enc = GzEncoder::new(tar_gz, Compression::default());    let mut tar = tar::Builder::new(enc);    tar.append_dir_all("", "/var/log")?;    tar.finish()?;    Ok(())}

The default behavior oftar::Builder differs from the GNUtar utility's defaultstar(1),notablytar::Builder::follow_symlinks(true) is the equivalent oftar --dereference.

Decompress a tarball while removing a prefix from the paths

Iterate over theArchive::entries. UsePath::strip_prefix to removethe specified path prefix (bundle/logs). Finally, extract thetar::EntryviaEntry::unpack.

use anyhow::Result;use std::fs::File;use std::path::PathBuf;use flate2::read::GzDecoder;use tar::Archive;fn main() -> Result<()> {    let file = File::open("archive.tar.gz")?;    let mut archive = Archive::new(GzDecoder::new(file));    let prefix = "bundle/logs";    println!("Extracted the following files:");    archive        .entries()?        .filter_map(|e| e.ok())        .map(|mut entry| -> Result<PathBuf, Box<dyn std::error::Error>> {            let path = entry.path()?.strip_prefix(prefix)?.to_owned();            entry.unpack(&path)?;            Ok(path)        })        .filter_map(|e| e.ok())        .for_each(|x| println!("> {}", x.display()));    Ok(())}