What Are Green Gadgets?

Green software, or portable software (referred to as Portable Application, Portable Software, or Green Software in English), refers to a class of small software, most of which are free software. The biggest feature is that the software can be used without installation and can be stored in flash memory ( It is called portable software), and no records (registry messages, etc.) will be left on the local computer after removal. In simple terms, green software refers to software that can be used directly without installation. Green software does not leave registry keys in the registry, so compared to ordinary software, green software has almost no impact on the system, so it is a good type of software. ^[1]

Chinese name: green software
Foreign name: Portable Application
nickname: Portable software

Meaning: Software that can be used without installation
Features: No installation required
Application: Little impact on the system

Green software software features

The green version of the software has the following strict characteristics (Chinese version is the green software that has been finished):

1 Do nothing with the registry.

2 Do not operate the system sensitive area, generally including the root directory of the system startup area, the installation directory (Windows directory), the program directory (ProgramFiles), and the account-specific directory.

3 Do not perform any write operations to directories outside of the directory in which they are located.

4 Because the program itself does not have any impact on any files except the directory where it is located, there are no installation and uninstallation issues at all.

5 Remove the program, just delete the directory where the program is located and the corresponding shortcut to complete the uninstall process (if you manually set a shortcut on the desktop or other location), as long as you do this, the program will be completely cleanly deleted from your computer Go without leaving any garbage.

6 No installation is required. Copying and duplication can be used at will (reinstalling the operating system is also possible). ^[2]

Basic classification of green software

Green software is divided into narrow green and broad green :

Green in the narrow sense can be called pure green software, which means that the software has not changed any part of the existing operating system. Except for the directory where the software is currently installed, you should not write anything. When deleting, you can directly delete the directory where it is located. It is similar to most previous DOS programs.

Green in the broad sense can be called fake green software, which means that no special installation program is required, and there are relatively few changes to the system. These changes can also be easily done manually, such as copying several dynamic libraries or importing the registry. The key here is These changes can be easily done manually, or can be done with the help of scripts such as batch processing.

Why are there two types ?

Although the narrow sense of green software is the most ideal, software that fully meets this definition is very rare, and quite a lot of software can be divided into the broad category of green. This includes the broad concept of green software and makes the concept of green software more significance.

So what do not meet the requirements of green software?

Mainly refers to software that is closely linked and integrated with the operating system. These software are not suitable for making green software. It is best to use the original installation program to install it. Such as IE6, which replaces many dynamic libraries in the system, it is difficult and not safe to complete this process manually. Another example is that most anti-virus software is not suitable for green software if it must monitor the underlying operation of the system in real time and make major changes to the system. There is also Microsoft's Office series software, which is more closely integrated with the system. However, this broad standard is more flexible. If someone understands the installation and production process of Office series software, it is also possible to make a broad green Office series. ^[1]

Green software installation and operation

In order to fully understand the definition of green software, it must be discussed from two aspects of the installation process and operation process of modern software.

Installation process : In the past, under the dos, there was no such so-called green software. The original program installation was basically simple copying or decompressing, and then configuring the config.sys and autoexec.bat files. With the development of windows, the application software is getting larger and more complicated, so some companies specialize in the production of installation programs. For example, InstallShield is a well-known and widely used installation software. Now Windows also has special The installer is Microsoft Installer. What does the installer do? The main purpose is to provide a simple and convenient setting environment for the program to be installed, without the user having to complete this step manually. The more complicated the configuration process, the more modifications to the system, the higher the dependence on the installer, and the The advantages of the program's easy to learn and use are inseparable from the good installation interface. The task of installing software is to provide the application with a preliminarily good and operational environment without the need for manual configuration by the user.

Running process : When the application is started, the configuration is read from the registry or configuration file. When running, the configuration can be modified, but this modification is generally based on the work done by the software installation. For example, the application cannot be changed. The installation position is up.

After understanding the difference between the installation process and the running process, it is easy to think of dividing the use of green software into a green installation process and a green running process according to these two stages. Green installation is the premise of green operation. Without green installation, there is no green operation. Green software must first be green installation. The ones that I mentioned earlier that are not suitable for green software standards are basically not green installation.

The basic meaning of green installation can also be divided into narrow and broad green installation:

1 Narrow green installation refers to directly copying or decompressing to the target directory, which does not need to be copied to the system directory or written to the registry. This is the ideal situation, or the role of the installer can be ignored except understanding the compression. For example, adding shortcuts to the start menu does not affect the operation of the system and software, which means that the role of the installation process is to copy files to the destination folder.

2 Green installation in a broad sense means that on the basis of narrow copying, some dynamic libraries must be copied to the system directory, or necessary settings must be imported into the registry, or some other configuration must be performed, otherwise the application cannot run And, this configuration work should be relatively simple, and it is easy to undo these changes to the system.

Similarly, green operations can be divided into narrow and broad green operations:

1 Green run in the narrow sense refers to the fact that the software does not change the operating system's files and configurations at all-many small programs belong to this category, or the changes to the system are undone after the end of the run, such as loading a driver while running and exit When uninstalling the driver, the INI file being operated is in its own program directory.

2 In a broad sense, green running means that the current settings can be changed through the program itself, such as changing the current software operation mode, or being associated with certain file suffixes, or leaving the current software settings in the registry, that is, There are permanent changes to the system's registry, but these changes are made by the application itself, without the need for other programs or by hand.

Comprehensive green installation and green operation can divide green software into:

1 Green installation in the narrow sense, meanwhile, software running in the green sense in the narrow sense, without any changes to the operating system.

2 Green installation in the narrow sense, green running software in the broad sense, the software configuration is done by the software itself, not through the installation program.

3 Green installation in a broad sense, green operation in a narrow sense, the software configuration work is done by the installation program, the software itself cannot modify the configuration, and if there is no configuration work, the software cannot run normally.

4 Generalized green installation, generalized green operation, the most complicated kind of green software, the software configuration work is done by the installation program, but the software itself can modify the configuration, and if there is no configuration work, the software cannot run normally.

Only the first category belongs to the narrowly defined green software, and the other three categories belong to the broad category of green software. ^[3]

Green software production method

The production of green software is referred to as "greening" of the software. The production of green software is actually the work of completing the installation program by ourselves. There is no fixed method, basically guessing and experimenting, different types of green software have different production strategies.

When you get a new piece of software and want to make it green, you generally follow these steps:

Green software judgment

It refers to guessing whether this software can be made into green software. From the function and your understanding of it, if you think that the software is closely related to the system, don't continue. It is safest and most convenient to use the original installation program. Such examples include directx9, IE6, Norton's anti-virus software and so on. Such judgment can save you time, of course, you can ignore this step and try to make green software, then go to step 2.

Green software

There are different methods for different software, there are no certain rules, but in general, it is to understand the software installation process and switch to green installation. In this process, you may need to try multiple methods, or you may end up with software. Complexity or certain characteristics that make it impossible to green. Be prepared for failure. Specific greening methods will be described later.

Green software testing

The test after greening is best tested in a freshly installed operating system, and if you want to use this software in multiple operating systems, you must also test in other operating systems. Some software files follow the operating system. The difference is different, at this time you need to carry out the "greening" process in different operating systems, and finally integrate it into a complete green software that adapts to multiple operating platforms. ^[4]

Green software greening method

The "greening" method requires choosing different "greening" methods based on experience, and may also need to continuously try different methods until it is successful. According to the order of easy change, the specific methods include:

Green software virtualization

The so-called virtualization is to install applications to some lightweight virtual systems. These virtual systems are very lightweight and less than 6M, but they can be installed and run software independently, like real Windows. Your own independent desktop. The virtual system achieves the goal of separating the operating system from applications, and any application installed in the virtual system can be flexibly migrated between different Windows operating systems. Therefore, we can use it to make green software, especially software that cannot be produced by conventional methods, and it will be easier to implement using virtualization.

Green software decompression

This is the simplest method, which is to try whether you can directly unzip the software. Try it with Winzip and Winrar to see if you can directly open the compressed installation file. If you can't open it, then change to another method. If you can, then congratulations, this software is mostly green installed software (with some exceptions, such as EmEditor), extract the files in the compressed package directly to the target path, and then test whether the software functions normally. If the function is normal, then "Greening" is successful, if it is not used normally, then change to another method. The characteristic of this type of software is that the work of the installer can be completely done by the software itself.

Green software installation and then uninstall

It is also an easier method. It is completely manual labor, which means directly installing the software, then copying the program, and finally uninstalling the installation program. If the installer of this software is only used to copy files and generate shortcuts, then it is a green installation and you can use this method.

Green software decompile installer

This method requires brainpower, which is to select the corresponding decompiler according to the production tool used by the installer, and then read the decompiled installation script to make green software. Most of the current software is produced using special installation tools, such as InstallShield, Wise, Inno Setup, Windows Installer, NSIS (Nullsoft), Installer VISE, where the Windows Installer format installation files (that is, MSI, MST files with suffixes) can be downloaded Orca, a free tool from Microsoft, is opened for viewing. There are also many free tools for installing files in the InstallShield format to decompress and view the scripts. Of course, there are many special installation tools, and many installation programs do not have corresponding decompilers. In this case, this method cannot be used.

Green Software Uninstaller

After the software installation is complete, most of them have uninstall methods. Uninstallation is the reverse process of installation. If you know how to uninstall, you can also speculate how to install. An uninstaller made by a special installation tool is usually uninstalled based on the information in a certain file. You can open this file with a plain text editor. In some cases, this file does not contain readable information at all, so you have to use another method. The specific process is to use method 2 first, then understand the uninstall process, and finally make green software based on the uninstall information.

Green software comparison system snapshot

When the previous methods fail, you can try this method. The specific idea is to first record the state of the system before installing the software, mainly including the status of all files in the registry and system directories. Then install the software. After the installation is complete, record the system status again. The last is to compare the status of the two systems before and after to learn what the installer does. This work is usually completed by special software, such as the free tool Regshot and the free tool WinInstall LE (in the directory VALUEADDRDPARTY \ MGMT \ WINSTLE \) of the Windows 2000 Sever CD. In most cases, you just need to compare the registry before and after the installation. At this time, there are still a large number of registry tools to choose from. After the system differences are found, the differences are broken down into two parts: the file part and the registry part. The file part refers to the files copied to the system directory, the files registered as COM components, and the registry part related to these files. The registry section simply refers to the remaining registry changes. For the file part, you can further distinguish between files that must be copied to the system directory (in this case, a few) and files that can be placed in the software's installation directory. Regarding the registry part, it distinguishes between the registry operations performed by the software's installer itself and the registry operations when registering COM components, and abandons the operations of other programs (such as Explorer). According to all these, writing a copy file, registering the COM component and importing the batch file into the registry can complete the production of green software. When the registry file contains path information, you can manually modify the registry file or convert the registry file into an INF file to achieve fully automatic path processing.

Green software registry green

This method is a simplified version of the above method 5. Now the software configuration is mostly written in the registry under "HKEY_LOCLAL_MACHINE \ SOFTWARE \ software company name" and "HKEY_CURRENT_USER \ SOFTWARE \ software company name". These 2 registry keys are exported to a REG file. The self-registered COM components need to export the following 4 functions: DllCanUnloadNow, DllGetClassObject, DllRegisterServer, DllUnregisterServer. You can use the vc built-in dependency.exe to find out which dynamic link library is a self-registered COM component. Finally, write a batch file to register COM components with regsvr32.exe and import the registry with regedit.exe.

By analyzing the actions of the installer above, the work of the installer is broken down into copying files, registering COM components, installing service drivers, and registry configuration. Although the registry configuration can cover the steps of registering COM components and installing service drivers , But separating these clearly helps to make green-installed software. For software that requires more complicated steps to install, it is safer to use the original installer. ^[4]