How to Use the Command 'shar' (with examples)
The shar command is a utility that creates a shell archive out of files, which can be distributed and later extracted to retrieve the original files. A shell archive is essentially a self-extracting shell script that contains the original files in an encoded format, making it easy to manage and share collections of files in Unix-like operating systems. It’s especially useful for packaging and distributing source code and other resources in a single file.
Use case 1: Create a Shell Script that Extracts Files From Itself
Code:
shar path/to/file1 path/to/file2 ... > path/to/archive.sh
Motivation:
Imagine you’re a software developer who has written several scripts or pieces of code and you want to share them with a colleague or upload them for a client to download. You could send all the files individually, but that could be cumbersome and error-prone. Packaging them all into a single self-extracting archive simplifies the process, ensuring that nothing gets lost and that the receiver has a straightforward way to unpack all the files.
Explanation:
shar: This is the command used to create a shell archive. It takes one or more files as input and outputs a shell script.path/to/file1 path/to/file2 ...: These are the paths to the files you wish to include in your shell archive. You may specify as many files as you need, each separated by a space. The files will be packed into a shell script.>: This is the redirection operator, which sends the output of the command to a file rather than displaying it on the terminal.path/to/archive.sh: This is the path and filename of the shell script that will be created. This script, when executed, will extract and reconstruct the original files.
Example Output:
Let’s say you run the command with two files, script1.sh and script2.sh, in your current directory:
shar script1.sh script2.sh > my_archive.sh
The command results in a new file named my_archive.sh. Inside the terminal, there might not be visible output, but the new shell script file my_archive.sh will be created. When you or someone else runs sh my_archive.sh, it extracts script1.sh and script2.sh in the same directory where the archive is executed.
Conclusion
The shar command is a practical tool for packaging multiple files into a single distributable shell script. This ensures easier file sharing and maintains the integrity of the file collection by bundling them together. This guide explored one particular use case for shar, illustrating the significance of creating a self-extracting archive to simplify file management and distribution tasks in Unix-like systems.
