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diff --git a/lib/libarchive/README b/lib/libarchive/README new file mode 100644 index 0000000..0c4758a --- /dev/null +++ b/lib/libarchive/README @@ -0,0 +1,102 @@ +$FreeBSD$ + +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: + * libarchive.3 gives an overview of the library as a whole + * archive_read.3, archive_write.3, and archive_write_disk.3 provide + detailed calling sequences for the read and write APIs + * archive_entry.3 details the "struct archive_entry" utility class + * libarchive-formats.5 documents the file formats supported by the library + * tar.5 provides some detailed information about a variety of different + "tar" formats. + +You should also read the copious comments in "archive.h" and the source +code for the sample "bsdtar" and "minitar" programs for more details. +Please let me know about any errors or omissions you find. + +Currently, the library automatically detects and reads the following: + * gzip compression + * bzip2 compression + * compress/LZW compression + * lzma and xz 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) + * ISO9660 CD-ROM images (with optional Rockridge or Joliet extensions) + * ZIP archives (with uncompressed or "deflate" compressed entries) + * GNU and BSD 'ar' archives + * 'mtree' format + +The library can write: + * gzip compression + * bzip2 compression + * compress/LZW compression + * lzma and xz 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 + * SVR4 "newc" cpio + * shar archives + * ZIP archives (with uncompressed or "deflate" compressed entries) + * GNU and BSD 'ar' archives + * 'mtree' format + +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 + independent. + + * On read, compression and format are always detected automatically. + + * 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. + + * 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. + + * The object-style approach allows you to have multiple archive streams + open at once. bsdtar uses this in its "@archive" extension. + + * 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, the archive_write_disk interface + treats a directory as if it were an archive so you can copy + from archive->disk using the same code you use for archive->archive + transfers. + + * Note: "pax interchange format" is really an extended tar format, + despite what the name says. |