Crate ar [] [src]

A library for encoding/decoding Unix archive files.

This library provides utilities necessary to manage Unix archive files (as generated by the standard ar command line utility) abstracted over a reader or writer. This library provides a streaming interface that avoids having to ever load a full archive entry into memory.

The API of this crate is meant to be similar to that of the tar crate.

Format variants

Unix archive files come in several variants, of which three are the most common:

Currently, this crate supports reading all three of these variants, but only supports writing the BSD/common variant.

Example usage

Writing an archive:

use ar::Builder;
use std::fs::File;
// Create a new archive that will be written to foo.a:
let mut builder = Builder::new(File::create("foo.a").unwrap());
// Add foo/bar.txt to the archive, under the name "bar.txt":
// Add foo/baz.txt to the archive, under the name "hello.txt":
let mut file = File::open("foo/baz.txt").unwrap();
builder.append_file(b"hello.txt", &mut file).unwrap();

Reading an archive:

use ar::Archive;
use std::fs::File;
use std::io;
use std::str;
// Read an archive from the file foo.a:
let mut archive = Archive::new(File::open("foo.a").unwrap());
// Iterate over all entries in the archive:
while let Some(entry_result) = archive.next_entry() {
    let mut entry = entry_result.unwrap();
    // Create a new file with the same name as the archive entry:
    let mut file = File::create(
    // The Entry object also acts as an io::Read, so we can easily copy the
    // contents of the archive entry into the file:
    io::copy(&mut entry, &mut file).unwrap();



A structure for reading archives.


A structure for building archives.


Representation of an archive entry.


Representation of an archive entry header.


An iterator over the symbols in the symbol table of an archive.



Variants of the Unix archive format.