2004-02-09 23:22:54 +00:00
|
|
|
$FreeBSD$
|
|
|
|
|
|
|
|
libarchive: a library for reading and writing streaming archives
|
|
|
|
|
|
|
|
This is all under a BSD license. Use, enjoy, but don't blame me if it breaks!
|
|
|
|
|
|
|
|
Documentation:
|
2004-07-12 01:54:37 +00:00
|
|
|
* libarchive.3 gives an overview of the library as a whole
|
|
|
|
* archive_read.3 and archive_write.3 provide detailed calling
|
2004-02-09 23:22:54 +00:00
|
|
|
sequences for the read and write APIs
|
2004-07-12 01:54:37 +00:00
|
|
|
* archive_entry.3 details the "struct archive_entry" utility class
|
2004-08-04 06:19:31 +00:00
|
|
|
* libarchive-formats.5 documents the file formats supported by the library
|
|
|
|
* tar.5 provides some detailed information about a variety of different
|
|
|
|
"tar" formats.
|
2004-02-09 23:22:54 +00:00
|
|
|
|
|
|
|
You should also read the copious comments in "archive.h" and the source
|
|
|
|
code for the sample "bsdtar" program for more details. Please let me know
|
|
|
|
about any errors or omissions you find. (In particular, I no doubt missed
|
2004-07-12 01:54:37 +00:00
|
|
|
a few things when researching the tar.5 page.)
|
|
|
|
|
|
|
|
Currently, the library automatically detects and reads the following:
|
|
|
|
* gzip compression
|
|
|
|
* bzip2 compression
|
|
|
|
* compress/LZW compression
|
|
|
|
* GNU tar format (including GNU long filenames, long link names, and
|
|
|
|
sparse files)
|
|
|
|
* Solaris 9 extended tar format (including ACLs)
|
|
|
|
* Old V7 tar archives
|
|
|
|
* POSIX ustar
|
|
|
|
* POSIX pax interchange format
|
|
|
|
* POSIX octet-oriented cpio
|
|
|
|
* SVR4 ASCII cpio
|
|
|
|
* Binary cpio (big-endian or little-endian)
|
|
|
|
|
|
|
|
The library can write:
|
|
|
|
* gzip compression
|
|
|
|
* bzip2 compression
|
|
|
|
* POSIX ustar
|
|
|
|
* POSIX pax interchange format
|
|
|
|
* "restricted" pax format, which will create ustar archives except for
|
|
|
|
entries that require pax extensions (for long filenames, ACLs, etc).
|
|
|
|
* POSIX octet-oriented cpio
|
|
|
|
* shar archives
|
2004-02-09 23:22:54 +00:00
|
|
|
|
|
|
|
Notes:
|
|
|
|
* This is a heavily stream-oriented system. There is no direct
|
|
|
|
support for in-place modification or random access and no intention
|
|
|
|
of ever adding such support. Adding such support would require
|
|
|
|
sacrificing a lot of other features, so don't bother asking.
|
|
|
|
|
|
|
|
* The library is designed to be extended with new compression and
|
|
|
|
archive formats. The only requirement is that the format be
|
|
|
|
readable or writable as a stream and that each archive entry be
|
2004-07-12 01:54:37 +00:00
|
|
|
independent.
|
|
|
|
|
|
|
|
* On read, compression and format are always detected automatically.
|
2004-02-09 23:22:54 +00:00
|
|
|
|
2004-07-12 01:54:37 +00:00
|
|
|
* I've attempted to minimize static link pollution. If you don't
|
|
|
|
explicitly invoke a particular feature (such as support for a
|
|
|
|
particular compression or format), it won't get pulled in.
|
|
|
|
In particular, if you don't explicitly enable a particular
|
|
|
|
compression or decompression support, you won't need to link
|
|
|
|
against the corresponding compression or decompression libraries.
|
|
|
|
This also reduces the size of statically-linked binaries in
|
|
|
|
environments where that matters.
|
2004-02-09 23:22:54 +00:00
|
|
|
|
2004-07-12 01:54:37 +00:00
|
|
|
* On read, the library accepts whatever blocks you hand it.
|
|
|
|
Your read callback is free to pass the library a byte at a time
|
|
|
|
or mmap the entire archive and give it to the library at once.
|
|
|
|
On write, the library always produces correctly-blocked
|
|
|
|
output.
|
2004-02-09 23:22:54 +00:00
|
|
|
|
2004-07-12 01:54:37 +00:00
|
|
|
* The object-style approach allows you to have multiple archive streams
|
|
|
|
open at once. bsdtar uses this in its "@archive" extension.
|
2004-02-09 23:22:54 +00:00
|
|
|
|
|
|
|
* The archive itself is read/written using callback functions.
|
|
|
|
You can read an archive directly from an in-memory buffer or
|
|
|
|
write it to a socket, if you wish. There are some utility
|
|
|
|
functions to provide easy-to-use "open file," etc, capabilities.
|
|
|
|
|
|
|
|
* The read/write APIs are designed to allow individual entries
|
|
|
|
to be read or written to any data source: You can create
|
|
|
|
a block of data in memory and add it to a tar archive without
|
|
|
|
first writing a temporary file. You can also read an entry from
|
|
|
|
an archive and write the data directly to a socket. If you want
|
|
|
|
to read/write entries to disk, there are convenience functions to
|
|
|
|
make this especially easy.
|
|
|
|
|
|
|
|
* Note: "pax interchange format" is really an extended tar format,
|
|
|
|
despite what the name says.
|