|LIBARCHIVE(3)||Library Functions Manual||LIBARCHIVE(3)|
libarchivelibrary provides a flexible interface for reading and writing archives in various formats such as tar and cpio.
libarchivealso supports reading and writing archives compressed using various compression filters such as gzip and bzip2. The library is inherently stream-oriented; readers serially iterate through the archive, writers serially add things to the archive. In particular, note that there is currently no built-in support for random access nor for in-place modification.
When reading an archive, the library automatically detects the format and the compression. The library currently has read support for:
When writing an archive, you can specify the compression to be used and the format to use. The library can write
The read and write APIs are accessed through the
archive_read_XXX() functions and the
archive_write_XXX() functions, respectively, and
either can be used independently of the other.
The rest of this manual page provides an overview of the library operation. More detailed information can be found in the individual manual pages for each API or utility function.
archive_read_extract(); using it directly can provide greater control over how entries get written to disk. This API also makes it possible to share code between archive-to-archive copy and archive-to-disk extraction operations.
All of the functions utilize an opaque struct archive datatype that provides access to the archive contents.
The struct archive_entry structure contains a complete description of a single archive entry. It uses an opaque interface that is fully documented in archive_entry(3).
Users familiar with historic formats should be aware that the newer variants have eliminated most restrictions on the length of textual fields. Clients should not assume that filenames, link names, user names, or group names are limited in length. In particular, pax interchange format can easily accommodate pathnames in arbitrary character sets that exceed PATH_MAX.
ARCHIVE_OK(zero) on success, non-zero on error. The return value indicates the general severity of the error, ranging from
ARCHIVE_WARN, which indicates a minor problem that should probably be reported to the user, to
ARCHIVE_FATAL, which indicates a serious problem that will prevent any further operations on this archive. On error, the
archive_errno() function can be used to retrieve a numeric error code (see errno(2)). The
archive_error_string() returns a textual error message suitable for display.
archive_write_new() return pointers to an allocated
and initialized struct archive object.
archive_write_data() return a count of the number of
bytes actually read or written. A value of zero indicates the end of the
data for this entry. A negative value indicates an error, in which case the
archive_error_string() functions can be used to
obtain more information.
libarchivelibrary first appeared in FreeBSD 5.3.
libarchivelibrary was originally written by Tim Kientzle ⟨firstname.lastname@example.org⟩.
Conversely, of course, not all of the information that can be stored in an struct archive_entry is supported by all formats. For example, cpio formats do not support nanosecond timestamps; old tar formats do not support large device numbers.
The ISO9660 reader cannot yet read all ISO9660 images; it should learn how to seek.
The AR writer requires the client program to use two passes, unlike all other libarchive writers.
|March 18, 2012||Mac OS X 10.13|