Compression & Archiving

Commands for compressing and decompressing files with gzip, and creating or extracting archives with tar.

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gzip

Compress files using the gzip format. By default, replaces each file with a compressed .gz version.

Syntax

gzip [OPTIONS] FILE...

Flags

Flag	Description
-d	Decompress (same as gunzip)
-c	Write output to stdout instead of replacing the file
-k	Keep the original file (do not delete after compress/decompress)
-f	Force overwrite of output files
-v	Verbose — show compression ratio for each file
-l	List compression statistics instead of compressing
-1 .. -9	Compression level (-1 fastest, -9 smallest, default -6)

Return type

With -l, each result is a PsBash.GzipListOutput object:

Property	Type	Description
CompressedSize	int	Size of the compressed file in bytes
UncompressedSize	int	Original uncompressed size in bytes
Ratio	string	Compression ratio as a percentage (e.g. "72.5%")
FileName	string	Path to the compressed file
BashText	string	Formatted text output

With -v, returns BashObject lines showing the compression ratio per file.

Examples

# Compress a file, keeping the original
gzip -k data.csv

# Compress with maximum compression
gzip -9 largefile.bin

# List compression statistics for a .gz file
gzip -l archive.gz

# Access typed properties from the list output
$info = gzip -l backup.gz
$info.CompressedSize     # 14320
$info.UncompressedSize   # 52480
$info.Ratio              # "72.7%"

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gunzip

Decompress gzip-compressed files. This is an alias for gzip -d — it automatically sets the decompress flag.

Syntax

gunzip [OPTIONS] FILE...

Flags

Flag	Description
-c	Write decompressed output to stdout
-k	Keep the .gz file after decompression
-f	Force overwrite of output files
-v	Verbose — show compression ratio

Note

gunzip shares the same flags as gzip. The -d flag is implicit — you do not need to pass it.

Examples

# Decompress a file, removing the .gz
gunzip data.csv.gz

# Decompress but keep the original .gz file
gunzip -k archive.gz

# Decompress to stdout for piping
gunzip -c logs.gz | grep 'ERROR'

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zcat

Decompress gzip files and write the content to stdout. This is equivalent to gzip -dc — both decompress and stdout flags are set automatically.

Syntax

zcat FILE...

Examples

# View compressed file contents
zcat readme.txt.gz

# Pipe decompressed content into other commands
zcat access.log.gz | grep '404' | wc -l

# Preview the first few lines of a compressed file
zcat data.csv.gz | head 5

Tip

zcat always writes to stdout and never modifies the original file, so there is no need for the -k flag.

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tar

Create, extract, and list archive files. Uses System.IO.Compression.ZipArchive internally, with optional gzip wrapping via the -z flag.

Syntax

tar [OPTIONS] [FILE...]

Flags

Flag	Description
-c	Create a new archive
-x	Extract files from an archive
-t	List the contents of an archive
-f FILE	Specify the archive filename (required)
-z	Filter the archive through gzip (compress on create, decompress on extract/list)
-v	Verbose — print filenames as they are processed
-C DIR	Change to DIR before extracting
--exclude=PATTERN	Exclude files matching the glob pattern

Return type

With -t, each entry is a PsBash.TarListOutput object:

Property	Type	Description
Name	string	Filename within the archive
Size	long	Uncompressed size in bytes
ModifiedDate	DateTime	Last modification timestamp
BashText	string	Entry path as displayed in the listing

Examples

# Create a gzip-compressed archive from a directory
tar -czf project.tar.gz src/

# Extract a gzip-compressed archive to a specific directory
tar -xzf project.tar.gz -C /tmp/output

# List contents of an archive
tar -tzf backup.tar.gz

# Access typed properties from the listing
$entries = tar -tzf project.tar.gz
$entries[0].Name          # "app.js"
$entries[0].Size          # 2048
$entries[0].ModifiedDate  # 4/1/2026 3:22:00 PM

# Create an archive excluding test files
tar -czf release.tar.gz src/ --exclude=*.test.ps1

# Verbose extract to see each file as it is written
tar -xzvf archive.tar.gz