Read and write ar containers — the outermost layer of a .deb.
A .deb is a plain Unix ar archive whose members are, in order,
debian-binary, control.tar.*, and data.tar.*. This module reads those
members into {name, bytes} pairs and writes them back out.
Determinism
write/1 produces a byte-for-byte reproducible archive: every member header
carries mtime 0, uid 0, gid 0, and mode 0o644, and no symbol table
is emitted. (A symbol table — the __.SYMDEF / / member that macOS's ar
injects — is meaningless for a .deb and breaks dpkg; its absence here is
the whole reason this writer exists.)
Example
iex> deb = Debkit.Ar.write([
...> {"debian-binary", "2.0\n"},
...> {"control.tar.gz", <<1, 2, 3>>}
...> ]) |> elem(1)
iex> {:ok, members} = Debkit.Ar.read(deb)
iex> Enum.map(members, &elem(&1, 0))
["debian-binary", "control.tar.gz"]Summary
Functions
Reads an ar container into its members, in archive order.
Like read/1 but returns the members directly, raising Debkit.Error on failure.
Writes members to a deterministic ar archive.
Like write/1 but returns the bytes directly, raising Debkit.Error on failure.
Types
Functions
@spec read(binary()) :: {:ok, [member()]} | {:error, Debkit.error()}
Reads an ar container into its members, in archive order.
Returns {:error, :corrupt} if binary is not a well-formed ar archive.
Examples
iex> {:ok, ar} = Debkit.Ar.read(Debkit.Ar.write!([{"a", "x"}]))
iex> ar
[{"a", "x"}]Like read/1 but returns the members directly, raising Debkit.Error on failure.
@spec write([member()]) :: {:ok, binary()} | {:error, Debkit.error()}
Writes members to a deterministic ar archive.
Each member is a {name, contents} pair; members are written in the order
given. Returns {:error, :name_too_long} if a name exceeds what the ar
format can store inline (the names a .deb uses are always short).
Examples
iex> {:ok, bytes} = Debkit.Ar.write([{"debian-binary", "2.0\n"}])
iex> is_binary(bytes)
trueLike write/1 but returns the bytes directly, raising Debkit.Error on failure.