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diff --git a/archivers/libarchive/files/doc/text/libarchive.3.txt b/archivers/libarchive/files/doc/text/libarchive.3.txt index 875700fc0bb..484642460dc 100644 --- a/archivers/libarchive/files/doc/text/libarchive.3.txt +++ b/archivers/libarchive/files/doc/text/libarchive.3.txt @@ -1,157 +1,121 @@ -LIBARCHIVE(3) NetBSD Library Functions Manual LIBARCHIVE(3) +LIBARCHIVE(3) BSD Library Functions Manual LIBARCHIVE(3) NAME - libarchive -- functions for reading and writing streaming archives - -LIBRARY - Reading and Writing Streaming Archives Library (libarchive, -larchive) + libarchive — functions for reading and writing streaming archives OVERVIEW The libarchive library provides a flexible interface for reading and - writing streaming archive files such as tar and cpio. 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 no built-in support for random access nor for in-place modifica- - tion. + writing archives in various formats such as tar and cpio. libarchive + also supports reading and writing archives compressed using various com‐ + pression 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 modifi‐ + cation. When reading an archive, the library automatically detects the format and the compression. The library currently has read support for: - old-style tar archives, - most variants of the POSIX ``ustar'' format, - the POSIX ``pax interchange'' format, - GNU-format tar archives, - most common cpio archive formats, - ISO9660 CD images (with or without RockRidge extensions), - Zip archives. + · old-style tar archives, + · most variants of the POSIX “ustar” format, + · the POSIX “pax interchange” format, + · GNU-format tar archives, + · most common cpio archive formats, + · ISO9660 CD images (including RockRidge and Joliet extensions), + · Zip archives, + · ar archives (including GNU/SysV and BSD extensions), + · Microsoft CAB archives, + · LHA archives, + · mtree file tree descriptions, + · RAR archives, + · XAR archives. The library automatically detects archives compressed with gzip(1), - bzip2(1), or compress(1) and decompresses them transparently. + bzip2(1), xz(1), lzip(1), or compress(1) and decompresses them transpar‐ + ently. It can similarly detect and decode archives processed with + uuencode(1) or which have an rpm(1) header. When writing an archive, you can specify the compression to be used and - the format to use. The library can write - POSIX-standard ``ustar'' archives, - POSIX ``pax interchange format'' archives, - POSIX octet-oriented cpio archives, - two different variants of shar archives. + the format to use. The library can write + · POSIX-standard “ustar” archives, + · POSIX “pax interchange format” archives, + · POSIX octet-oriented cpio archives, + · Zip archive, + · two different variants of shar archives, + · ISO9660 CD images, + · 7-Zip archives, + · ar archives, + · mtree file tree descriptions, + · XAR archives. Pax interchange format is an extension of the tar archive format that eliminates essentially all of the limitations of historic tar formats in - a standard fashion that is supported by POSIX-compliant pax(1) implemen- + a standard fashion that is supported by POSIX-compliant pax(1) implemen‐ tations on many systems as well as several newer implementations of tar(1). Note that the default write format will suppress the pax extended attributes for most entries; explicitly requesting pax format will enable those attributes for all entries. - The read and write APIs are accessed through the archive_read_XXX() func- + The read and write APIs are accessed through the archive_read_XXX() func‐ tions 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 opera- + The rest of this manual page provides an overview of the library opera‐ tion. More detailed information can be found in the individual manual pages for each API or utility function. READING AN ARCHIVE - To read an archive, you must first obtain an initialized struct archive - object from archive_read_new(). You can then modify this object for the - desired operations with the various archive_read_set_XXX() and - archive_read_support_XXX() functions. In particular, you will need to - invoke appropriate archive_read_support_XXX() functions to enable the - corresponding compression and format support. Note that these latter - functions perform two distinct operations: they cause the corresponding - support code to be linked into your program, and they enable the corre- - sponding auto-detect code. Unless you have specific constraints, you - will generally want to invoke archive_read_support_compression_all() and - archive_read_support_format_all() to enable auto-detect for all formats - and compression types currently supported by the library. - - Once you have prepared the struct archive object, you call - archive_read_open() to actually open the archive and prepare it for read- - ing. There are several variants of this function; the most basic expects - you to provide pointers to several functions that can provide blocks of - bytes from the archive. There are convenience forms that allow you to - specify a filename, file descriptor, FILE * object, or a block of memory - from which to read the archive data. Note that the core library makes no - assumptions about the size of the blocks read; callback functions are - free to read whatever block size is most appropriate for the medium. - - Each archive entry consists of a header followed by a certain amount of - data. You can obtain the next header with archive_read_next_header(), - which returns a pointer to an struct archive_entry structure with infor- - mation about the current archive element. If the entry is a regular - file, then the header will be followed by the file data. You can use - archive_read_data() (which works much like the read(2) system call) to - read this data from the archive. You may prefer to use the higher-level - archive_read_data_skip(), which reads and discards the data for this - entry, archive_read_data_to_buffer(), which reads the data into an in- - memory buffer, archive_read_data_to_file(), which copies the data to the - provided file descriptor, or archive_read_extract(), which recreates the - specified entry on disk and copies data from the archive. In particular, - note that archive_read_extract() uses the struct archive_entry structure - that you provide it, which may differ from the entry just read from the - archive. In particular, many applications will want to override the - pathname, file permissions, or ownership. - - Once you have finished reading data from the archive, you should call - archive_read_close() to close the archive, then call - archive_read_finish() to release all resources, including all memory - allocated by the library. - - The archive_read(3) manual page provides more detailed calling informa- - tion for this API. + See archive_read(3). WRITING AN ARCHIVE - You use a similar process to write an archive. The archive_write_new() - function creates an archive object useful for writing, the various - archive_write_set_XXX() functions are used to set parameters for writing - the archive, and archive_write_open() completes the setup and opens the - archive for writing. - - Individual archive entries are written in a three-step process: You first - initialize a struct archive_entry structure with information about the - new entry. At a minimum, you should set the pathname of the entry and - provide a struct stat with a valid st_mode field, which specifies the - type of object and st_size field, which specifies the size of the data - portion of the object. The archive_write_header() function actually - writes the header data to the archive. You can then use - archive_write_data() to write the actual data. - - After all entries have been written, use the archive_write_finish() func- - tion to release all resources. - - The archive_write(3) manual page provides more detailed calling informa- - tion for this API. + See archive_write(3). + +WRITING ENTRIES TO DISK + The archive_write_disk(3) API allows you to write archive_entry(3) + objects to disk using the same API used by archive_write(3). The + archive_write_disk(3) API is used internally by archive_read_extract(); + using it directly can provide greater control over how entries get writ‐ + ten to disk. This API also makes it possible to share code between ar‐ + chive-to-archive copy and archive-to-disk extraction operations. + +READING ENTRIES FROM DISK + The archive_read_disk(3) supports for populating archive_entry(3) objects + from information in the filesystem. This includes the information acces‐ + sible from the stat(2) system call as well as ACLs, extended attributes, + and other metadata. The archive_read_disk(3) API also supports iterating + over directory trees, which allows directories of files to be read using + an API compatible with the archive_read(3) API. DESCRIPTION Detailed descriptions of each function are provided by the corresponding manual pages. - All of the functions utilize an opaque struct archive datatype that pro- + All of the functions utilize an opaque struct archive datatype that pro‐ vides 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 docu- + single archive entry. It uses an opaque interface that is fully docu‐ mented in archive_entry(3). - Users familiar with historic formats should be aware that the newer vari- + Users familiar with historic formats should be aware that the newer vari‐ ants 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 + group names are limited in length. In particular, pax interchange format can easily accommodate pathnames in arbitrary character sets that exceed PATH_MAX. RETURN VALUES - Most functions return 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 mes- - sage suitable for display. - - archive_read_new() and archive_write_new() return pointers to an allo- + Most functions return 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_read_new() and archive_write_new() return pointers to an allo‐ cated and initialized struct archive object. archive_read_data() and archive_write_data() return a count of the number - of bytes actually read or written. A value of zero indicates the end of + 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_errno() and archive_error_string() functions can be used to obtain more information. @@ -168,7 +132,8 @@ HISTORY The libarchive library first appeared in FreeBSD 5.3. AUTHORS - The libarchive library was written by Tim Kientzle <kientzle@acm.org>. + The libarchive library was originally written by Tim Kientzle + <kientzle@acm.org>. BUGS Some archive formats support information that is not supported by struct @@ -179,7 +144,13 @@ BUGS 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 sup- + formats do not support nanosecond timestamps; old tar formats do not sup‐ port large device numbers. -NetBSD 5.0 August 19, 2006 NetBSD 5.0 + 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. + +BSD March 18, 2012 BSD |