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PeaZip
is a free cross-platform file archiver utility that provides an unified
portable GUI for many Open Source technologies like 7-Zip, FreeArc,
PAQ, UPX... free alternative to WinRar, WinZip and
similar
proprietary software.
- Create 7Z, ARC, BR, BZ2, GZ, *PAQ, PEA, QUAD/BALZ, TAR, UPX, WIM, XZ,
ZIP, ZST
files
- Open and extract ACE, ARJ, CAB, DMG, ISO, LHA,
RAR, UDF, ZIPX files and more, over 200 archive types
supported
Features of PeaZip includes: archives
opener and extractor, batch creation and extraction
of multiple
archives at once, convert files, create
self-extracting archives, split and join files,
strong encryption with two factor authentication, encrypted password
manager, secure deletion, find
duplicate files, calculate hash and checksum,
export job definition as script.
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What is TAR file format, TGZ
TBZ TXZ files
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TAR is
a popular archiving
format, mainstream for data backup and distribution purpose on Unix and
Unix-like systems, as BSD, Linux and derivates. In use since early Unix
versions, predating integrated archiving and compression formats like
zip and rar, it
was
later standardized by POSIX-1.1988 and POSIX.1-2001. Tar packages are
sometimes referred as "tarballs".
"Tarbomb" refers to a tar
package
purposely built to spam extraction directory with a large number of
files, effect that can be avoided by moders archivers simply employing
"extract to new folder" option.
Maximum size of a TAR
file
Current POSIX.1 2001 revision of the tar standard removed the old
limitation of 8 GB of maximum archive size for tar archives defined in
POSIX.1 1988 standard
TAR
file format doesn't
feature native data compression, so TAR archives are often
compressed
with an external utility like, but not only, GZip, BZip2, XZ (using
7-Zip / p7zip LZMA / LZMA2 compression algorithms), Brotli, Zstandard, and similar
tools to reduce archive's size, i.e. for more compact backup, or
smaller software distribution package.
Resulting compressed files
can be found named with single extension, e.g. TGZ, TBZ, TXZ, TZST, or
with double file extension,
e.g. TAR.GZ, TAR.BR, TAR.BZ2,
TAR.XZ, TAR.ZST.
Adding items to a tarball before compression stage is quivalent to
using solid compression,
which can be beneficial for optimizing output size.
Similarly, TAR also does
not natively support cryptography, but it is possible to compress the
TAR package with a compression format providing file encryption features
such as zip, 7z, arc, pea.
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When
it is recommended to use TAR format: it is a good choice for
distributing data on
Linux and
other Unix-like systems, combining it with .gz / .bz2 / .xz / Brotli /
Zstandard compression, in order
to
save bandwidth - if relevant for the intended use. |
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PeaZip fully support creation and
extraction of TAR files on Windows and Linux systems.
Read more
about .tar extension: TAR
specifications on GNU
software directory, TAR
file format Wikipedia
entry, GZip, BZip2, Google Brotli, and
Facebook Zstandard
compressors' official domains.
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.TAR
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no
maximum size POSIX.1 2001, previously GB max size POSIX.1 1988 |
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SPEED 
Tar format features extremely fast speed: archiving to TAR file is
equivalent - in speed - of
merging files, faster than raw file
copy as the process avoids overhead of creating a new filesystem
entry for each file. If compression is applied in the pipeline of the
job, it will be likely the speed performance limitating factor.
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COMPRESSION
RATIO 
Tar file type is not meant to provide compression, and rely on external
compressors in
pipeline (tar.gz, tar.br, tar.bz, tar.xz, tar.zst) from which depends
the results in
terms of compression ratio.
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ADVANCED
OPTIONS 
Tar standard is meant to provide only archiving of data and metadata.
Other features are
delegated, by specification's design, to external programs pipelined to
Tar command.
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Legitimate use of double file extension
PeaZip can handle and create files with double
extension; most common cases for having have a file with two extensions
are
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Compressed
containers
When a
compression only algorithm - most common ones are GZip Deflate compression, Brotli compression, BZip2 compression, LPAQ compression, Zstandard compression
or 7-Zip's lzma XZ compression -
is
applied to
multiple files, which consequnetly needs to be
consolidated into a single archive - most times a TAR file -
before the compression step (also known as solid mode compression).
This result in the first step archiving extension (e.g. creating a TAR archive file) being
pre-pended to second step compression extension (e.g. XZ).
Extracting
compressed tar files
(TAR.GZ / TAR.BR / TAR.BZ / TAR.LPAQ, TAR.XZ / TAR.ZST) could be
treated as
atomic,
single step operation, but usually (as in PeaZip, 7-Zip and other
archival utilities) extraction of compressed TAR files is a two step
process which firstly uncompress the TAR archive, and then unarchive
the contained files and folder structure.
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Spanned multi-volume archives
File spanning is
applied (often in a single pass) to output archive,
creating a set of volumes of desired size, with a numerator in the file
extension to declare what is the first volume and the progressive order
of data chunks, in example .R01, .Z01, etc
Some splitting standards adds the numerator information in a separate
extension, before or after usual archive extension, in example .7Z.001,
.7Z.002, .7Z.003 etc.
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Risks, security issues of "Hide known file
extensions" option
A completely unrelated
use of double file extension spread after Micorsoft set "Hide known
file types extensions" option enabled by default for Windows XP
and
newer systems - this is still the default behavior on Vista, 7, 8, 10 -
opening the ground for attack exploiting hidden files extensions.
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This option allows an
attacker to trivially add a file extension before
the true one in order to mask the real nature of the file - being the
last file extension hidden by default to end users by the system in
file browser and most applications following system's file browser
policies.
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In example, an executable virus named attachment.exe can be renamed in
attachment.doc.exe.
By deafult, end user would be prompted "attachment.doc" (or any other
harmless file extension used by the attacker, i.e. .jpeg, .mpg), but
once clicked the file would be executed as .exe file (true file
extension) by the system.
In this way an executable file that should trigger a great level of
awareness and caution from user (e.g. .exe, .scr, .bat, .vb, .js...)
can be easily masked as harmless, common, file type to mislead end user.
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PeaZip
file and archive browser never hide file extension, avoiding
this type of forgery.
Moreover PeaZip warns each time an executable or script file is being
executed from an archive, in this way 1) the user is made aware of the
potentially harmful nature of the file 2) the user can evaluate to
extract the whole archive before, as executable and script
files could need some archived resources (i.e. dll) to be available in
uncompressed form before properly running.
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Sometimes files with double extension are treated as suspicious ones,
but if it is the right case for executable ones (exe or script file
type as last extension), it is definitely NOT the case for archive
files with double extension, being TAR.something very common file types
- especially on *x systems.
Read more about this topic: what are file
extensions, list of
known file
types, TAR archive
format, which usually comes with a second extension (tar.gz, tar.bz)
declaring the compression scheme applied to the tar container.
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FAQ
> Archive file types > What are TAR files
Topics and search suggestions about what is TAR file format, what are
TBZ TGZ TXZ compressed archive types (equivalent to .tar.bz, .tar.gz,
.tar.xz extensions), GNU tar files features and
specifications:
what are
tgz compressed archives,
tbz file type,
max size of a tar archive,
unix archival formats,
tar standard,
features of tar archives,
TBZ, TGZ, TXZ extensions,
GNU tar format specs,
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what is
tar file format,
TAR files
specifications,
what is a tarball,
tar specs,
maximum size of tar files,
characteristics of tar files,
what is a tar archive,
tar.gz, tar.bz, tar.xz files
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faq
about .tar format,
max tar file size limit
what
are tar archives,
linux tar packages,
unix tar standard,
what are tar file features,
tarbomb definition,
GNU tar faq,
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tar.xz
extension,
archive files on linux systems,
txz file type,
tar format features,
maximum limit for tar file size,
tar archive characteristics,
tar format specs,
limitation for tar format max size
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