Compress and Decompressing Archives in Linux

Tips and Traps¶

Always test integrity of the compressed file before you throw away the original archives. I’ve seen a case before that a large zip file generated in Windows cannot be unzipped correctly in Linux. Not sure what happend though.
Zstd is currently the best compression/decompression tool. It supports different levels of compression. For a similar compression ratio, it is generally much faster than other compression tools.

zst or zstd¶

Extract archive.
```
 zstd -d /path/to/archive.ztd
```
Create a zst archive from a single file.
```
 zstd -19 -T0 /path/to/file/to/compress
```
If you want to compress a directory using zstd, you can tar it first. See the next section for more discussions.

tar.zstd or tar.zst¶

Extract archive.

 :::bash
 tar -I zstd -xvf archive.tar.zst

Create an archive.

 :::bash
 # max compression
 tar cf - Dropbox/ | zstd -19 -T0 > Dropbox.tar.zstd
 # good balance bewteen compression ratio and speed
 tar cf - Dropbox/ | zstd -9 -T0 > Dropbox.tar.zstd

tar.gz or tgz¶

List the content of an archive.
```
 :::bash
 tar -ztvf archive_name.tag.gz
```
Extract the content of an archive to the current directory.
```
 :::bash
 tar -zxvf archive_name.tag.gz
```
Extract the content of an archive to a directory named “exdir”.
```
 :::bash
 tar -zxvf archive_name.tag.gz -C exdir
```

Create an archive.

 :::bash
 tar -zcvf archive_name.tar.gz /path/to/file_or_dir

Create an archive with some files excluded.

 :::bash
 tar -zcvf archive_name.tar.gz --exclude='abc' --exclude='xyz' /path/to/file_or_dir

gz¶

# decompress
gunzip -c archive_name.gz > decompressed_file_name
# or
gzip -cd archive_name.gz > decompressed_file_name
# or
zcat archive_name.gz > decompressed_file_name

Notice that you have to use the -c option, otherwise, the original compressed file is removed.

tar.bz2¶

# list the archive contents
tar -jtvf archive_name.tar.bz2
# extract the archive contents to the current directory
tar -jxvf archive_name.tar.bz2
# extract the archive contents to a directory named "exdir"
tar -jxvf archive_name.tar.bz2 -C exdir

zip¶

List the content of an archive.
```
 :::bash
 unzip -l archive_name.zip
```
Test the integrity of an archive.
```
 :::bash
 unzip -t archive_name.zip
```
Extract the archive contents into the current directory.
```
 ::bash
 unzip archive_name.zip
```
Extract the archive contents into the directory “exdir”.
```
 :::bash
 unzip archive_name.zip -d exdir
```
Create a zip archive.
```
 :::bash
 zip -r archive_name.zip .
```

Create a zip archive with some files excluded.

 :::bash
 zip -r -x "Nothanks.jpg" archive.zip images/

rar¶

# list the archive contents
unrar l file_name
# test integrity of the archive
unrar t file_name
# extract the archive with full names
unrar x file_name

Jar¶

# extract the archive
jar xf jar-file [archived-file(s)]

7zip¶

# list the archive contents
7za l file_name
# test the archive contents
7za t file_name
# extract the archive contents with full names
7za x file_name
# extract a file/folder from the archive
7za x archive_name path_to_file_to_be_extracted

If the compressed archive is splitted into several smaller files, just replace file_name in the above commands with the name of the first file of the compressed archive.

For rar and 7za, I’m not sure whether there are options for creating a new directory to uncompress the archive into. However, you can always first create an empty directory, move the archive into it and then uncompress it.

Multiple Archives¶

The archive related commands (e.g., tar, zip, unzip, etc.) in Linux does not support decompressing from multiple archives or compressing files into multiple archives directly. To extract content from multiple archives, you need to first concatenate them into a single one. For example, you can use the following command to unzip archives BigDataLite-3.0.zip.001, BigDataLite-3.0.zip.002, BigDataLite-3.0.zip.003, BigDataLite-3.0.zip.004, BigDataLite-3.0.zip.005 and BigDataLite-3.0.zip.006.

# concatenate zipped archives into a single one
cat BigDataLite-3.0.zip.00? > BigDataLite-3.0.zip
# unzip the combined archive
unzip BigDataLite-3.0.zip

To compress files into multiple archives, you have to first compress them into a single archive using one of the commands introduced before and then split the single archive into multiple ones using the command split. For example, the following command split the archive WinTPC_1.tar.gz into smaller ones named WinTPC_1.tar.gz_part?? with size around 2.7G.

split -b 2700M -d WinTPC_1.tar.gz WinTPC_1.tar.gz_part

An alternative way (and better in my opinion) is to specify the number of archives (with about equal size) to split into.

split -n 5 -d xp_2.tar.gz xp_2.tar.gz_part