unzipsfx Command in Linux
The unzipsfx command is an extension of unzip with enhanced features to create self-extracting ZIP files. It helps users in attaching an executable stub at the start of ZIP files so that they are automatically extracted without invoking any other software. The feature is useful while releasing software, install packages, or archives that need to be automatically extracted.
While unzipsfx offers most of the common features shared by unzip, listing contents and verbose diagnostics features are not included.
Table of Contents
Here is a comprehensive guide to the options available with the unzipsfx command −
- Understanding of unzipsfx Command
- Syntax of unzipsfx Command
- unzipsfx Command Options
- Examples of unzipsfx Command in Linux
Understanding of unzipsfx Command
In contrast to normal ZIP files, unzipsfx-created archives do have an internal decompression engine. Rather than depending on the run-time name of the ZIP file to unpack, the utility identifies the archive by run-time name and processes its contents automatically.
Due to its minimalist design, some of the unzip functionality, such as enhanced listing (-l, -v) and decompression of old formats (reduce, shrink, implode), has been sacrificed. Support for extraction of encrypted archives and execution of commands on extraction can be added at compile time.
Syntax of unzipsfx Command
The basic syntax for executing a self-extracting archive is −
<unzipsfx_archive> [-cfptuz[ajnoqsCLV$]] [file(s) ... [-x xfile(s) ...]]
Where −
- <unzipsfx_archive> represents the executable self-extracting ZIP archive.
- [file(s)] is an optional list of specific files within the archive to extract.
- [-x xfile(s)] excludes specified files from extraction.
unzipsfx Command Options
The unzipsfx command provides various arguments and options that allow users to control how files are extracted, excluded, or processed.
General Arguments
These arguments allow users to define which files should be extracted or excluded, helping refine the extraction process for better control over file retrieval.
| Options | Description |
|---|---|
| file(s) ... | Allows selective extraction of specific files using wildcards (*, ?, [...]). |
| -x xfile(s) ... | Excludes files from extraction, preventing subdirectory files from being unpacked. |
| -d exdir | Extracts files into a specified directory instead of the current location (enabled if compiled with SFX_EXDIR). |
Extraction Options
These options define how files are extracted, whether displayed, tested, updated, or sent to standard output.
| Options | Description |
|---|---|
| -c | Extracts files to standard output. |
| -p | Displays extracted file content to the terminal without saving. |
| -f | Freshens existing files without adding new ones. |
| -u | Updates files by replacing outdated versions. |
| -t | Tests the archive's integrity without extracting. |
Modifiers for File Handling
File-handling modifiers enhance extraction behavior by controlling overwriting, filename formatting, directory structure, and silent operations.
| Options | Description |
|---|---|
| -a | Converts text files to the appropriate format for the system. |
| -n | Prevents overwriting existing files. |
| -o | Forces overwriting without confirmation. |
| -q | Runs quietly, suppressing output messages. |
| -C | Enables case-insensitive filename matching. |
| -L | Converts uppercase filenames to lowercase during extraction. |
| -j | Extracts files without maintaining directory structure. |
| -V | Preserves version numbers from the archive. |
Examples of unzipsfx Command in Linux
The following examples showcase real-world applications of unzipsfx, helping users create, extract, and manipulate self-extracting archives effortlessly across different systems.
- Creating a Self-Extracting Archive
- Creating a Self-Extracting Archive for Windows Systems
- Creating a Self-Extracting Archive in VMS
Creating a Self-Extracting Archive
You have a ZIP archive named backup.zip and want to convert it into a self-extracting archive −
cat unzipsfx backup.zip > backup_extract chmod 755 backup_extract zip -A backup_extract
Where −
- unzipsfx prepends an executable stub to the ZIP archive.
- chmod 755 backup_extract makes it executable so users can run it directly.
- zip -A backup_extract adjusts archive metadata for compatibility.
Creating a Self-Extracting Archive for Windows Systems
For Windows (MS-DOS, OS/2, NT), you need a different approach −
copy /b unzipsfx.exe+project_files.zip project_installer.exe zip -A project_installer.exe
It combines unzipsfx.exe with the ZIP file, making it runnable on Windows without additional tools.
Creating a Self-Extracting Archive in VMS
For VMS environments, use the following commands −
copy unzipsfx.exe,logs.zip logs_extract.exe logs_extract == "$currentdisk:[currentdir]logs_extract.exe" zip -A logs_extract.exe
The second command installs logs_extract.exe as a foreign command, allowing it to take arguments when executed.
Conclusion
The unzipsfx utility is a very useful program to build self-extracting archives so that files can be sent trouble-free without the need for special extraction software. Being aware of how to create, verify, and extract archives with various parameters will make users effective packers of software, logs, backup, and install files on various platforms.