NAME
Archive::Ar::Libarchive - Interface for manipulating ar archives with
libarchive
VERSION
version 2.05
SYNOPSIS
use Archive::Ar::Libarchive;
my $ar = Archive::Ar->new('libfoo.a');
$ar->add_data('newfile.txt', 'some contents', { uid => 101, gid => 102 });
$ar->add_files('./bar.tar.gz', 'bat.pl');
$ar->remove('file1', 'file2');
my $content = $ar->get_content('file3')->{data};
my @files = $ar->list_files;
$ar->write('libbar.a');
my @file_list = $ar->list_files;
DESCRIPTION
This module is a XS alternative to Archive::Ar that uses libarchive to
read and write ar BSD, GNU and common ar archives.
There is no standard for the ar format. Most modern archives are based
on a common format with two extension variants, BSD and GNU. Other
esoteric variants (such as AIX (small), AIX (big) and Coherent) vary
significantly from the common format and are not supported. Debian's
package format (.deb files) use the common format.
The interface attempts to be identical (with a couple of minor
extensions) to Archive::Ar and the documentation presented here is
based on that module. The diagnostic messages issued on error mostly
come directly from libarchive, so they will likely not match exactly
what Archive::Ar would produce, but it should issue a warning under
similar circumstances.
The main advantage of Archive::Ar over this module is that it is
written in pure perl, and thus does not require a compiler or
libarchive. As an XS module using libarchive it may be faster.
You may notice that the API to Archive::Ar::Libarchive and Archive::Ar
is similar to Archive::Tar and this was done intentionally to keep
similarity between the Archive::* modules.
METHODS
new
my $ar = Archive::Ar::Libarchive->new;
my $ar = Archive::Ar::Libarchive->new($filename);
my $ar = Archive::Ar::Libarchive->new($fh);
Returns a new Archive::Ar::Libarchive object. Without a filename or
glob, it returns an empty object. If passed a filename as a scalar or a
GLOB, it will attempt to populate from either of those sources. If it
fails, you will receive undef, instead of an object reference.
set_opt
$ar->set_opt($name, $value);
Assign option $name value $value. Supported options include:
warn
Warning level. Levels are zero for no warnings, 1 for brief warnings,
and 2 for warnings with a stack trace. Default is zero.
Warnings that originate with libarchive itself will not include a
stacktrace, even with a warn level set to 2.
chmod
Change the file permissions of files created when extracting. Default
is true (non-zero).
This option is provided only for compatibility with Archive::Ar.
Libarchive does not provide an equivalent to this option, so setting
it to false will has no effect.
same_perms
When setting file permissions, use the values in the archive
unchanged. If false, removes setuid bits and applies the user's
umask. Default is true.
In Archive::Ar this option is true for root only.
chown
Change the owners of extracted files, if possible. Default is true.
type
Archive type. May be GNU, BSD or COMMON, or undef if no archive has
been read. Defaults to the type of the archive read or undef.
symbols
Provide a filename for the symbol table, if present. If set, the
symbol table is treated as a file that can be read from or written to
an archive. It is an error if the filename provided matches the name
of a file in the archive. If undef, the symbol table is ignored.
Defaults to undef.
get_opt
my $value = $ar->get_opt($name);
Returns the value of the option $name.
type
my $type = $ar->type;
Returns the type of the ar archive. The type is undefined until an
archive is loaded. If the archive displays characteristics of a
GNU-style archive, GNU is returned. If it looks like a bsd-style
archive, BSD is returned. Otherwise, COMMON is returned. Note that
unless filenames exceed 16 characters in length, bsd archives look like
the common format.
clear
$ar->clear;
Clears the current in-memory archive.
read
my $br = $ar->read($filename);
my $br = $ar->read($fh);
This reads a new file into the object, removing any ar archive already
represented in the object. The argument may be either a filename,
filehandle or IO::Handle object. Returns the number of bytes read,
undef on failure.
read_memory
my $br = $ar->read_memory($data);
This reads information from the first parameter, and attempts to parse
and treat it like an ar archive. Like Archive::Ar::Libarchive#read, it
will wipe out whatever you have in the object and replace it with the
contents of the new archive, even if it fails. Returns the number of
bytes read (processed) if successful, undef otherwise.
contains_file
my $bool = $ar->contains_file($filename)
Returns true if the archive contains a file with the name $filename.
Returns undef otherwise.
extract
$ar->extract;
Extract all files from the archive. Extracted files are assigned the
permissions and modification time stored in the archive, and, if
possible, the user and group ownership. Returns true on success, undef
for failure.
extract_file
$ar->extract_file($filename);
Extracts a single file from the archive. The extracted file is assigned
the permissions and modification time stored in the archive, and, if
possible, the user and group ownership. Returns true on success, undef
for failure.
rename
$ar->rename($filename, $newname);
Changes the name of a file in the in-memory archive.
chmod
$ar->chmod($filename, $mode);
Change the permission mode of the member to $mode.
chown
$ar->chown($filename, $uid, $gid);
$ar->chown($filename, $uid);
Change the ownership of the member to user id $udi and (optionally)
group id $gid. Negative id values are ignored.
remove
my $count = $ar->remove(@pathnames);
my $count = $ar->remove(\@pathnames);
The remove method takes a filenames as a list or as an arrayref, and
removes them, one at a time, from the Archive::Ar object. This returns
the number of files successfully removed from the archive.
list_files
my @list = $ar->list_files;
my $list = $ar->list_files;
This lists the files contained inside of the archive by filename, as an
array. If called in a scalar context, returns a reference to an array.
add_files
$ar->add_files(@filenames);
$ar->add_files(\@filenames);
Takes an array or an arrayref of filenames to add to the ar archive, in
order. The filenames can be paths to files, in which case the path
information is stripped off. Filenames longer than 16 characters are
truncated when written to disk in the format, so keep that in mind when
adding files.
Due to the nature of the ar archive format,
Archive::Ar::Libarchive#add_files will store the uid, gid, mode, size,
and creation date of the file as returned by stat.
returns the number of files successfully added, or undef on failure.
add_data
my $size = $ar->add_data($filename, $data, $filedata);
Takes an filename and a set of data to represent it. Unlike
Archive::Ar::Libarchive#add_files, Archive::Ar::Libarchive#add_data is
a virtual add, and does not require data on disk to be present. The
data is a hash that looks like:
$filedata = {
uid => $uid, #defaults to zero
gid => $gid, #defaults to zero
date => $date, #date in epoch seconds. Defaults to now.
mode => $mode, #defaults to 0100644;
};
You cannot add_data over another file however. This returns the file
length in bytes if it is successful, undef otherwise.
write
my $content = $ar->write;
my $size = $ar->write($filename);
This method will return the data as an .ar archive, or will write to
the filename present if specified. If given a filename,
Archive::Ar::Libarchive#write will return the length of the file
written, in bytes, or undef on failure. If the filename already exists,
it will overwrite that file.
get_content
my $hash = get_content($filename);
This returns a hash with the file content in it, including the data
that the file would naturally contain. If the file does not exist or no
filename is given, this returns undef. On success, a hash is returned
with the following keys:
name
The file name
date
The file date (in epoch seconds)
uid
The uid of the file
gid
The gid of the file
mode
The mode permissions
size
The size (in bytes) of the file
data
The contained data
get_data
my $data = $ar->get_data($filename);
Returns a scalar containing the file data of the given archive member.
On error returns undef.
get_handle
my $handle = $ar->get_handle($filename);
Returns a file handle to the in-memory file data of the given archive
member. On error returns undef. This can be useful for unpacking nested
archives.
error
my $error_string = $ar->error($trace);
Returns the current error string, which is usually the last error
reported. If a true value is provided, returns the error message and
stack trace.
SEE ALSO
Alien::Libarchive
Archive::Ar
AUTHOR
Graham Ollis <plicease@cpan.org>
COPYRIGHT AND LICENSE
This software is copyright (c) 2013 by Graham Ollis.
This is free software; you can redistribute it and/or modify it under
the same terms as the Perl 5 programming language system itself.