Windows Script Host
The Microsoft Windows Script Host is an automation technology for Microsoft Windows operating systems that provides scripting abilities comparable to batch files, but with a wider range of supported features. This tool was first provided on Windows 95 after Build 950a on the installation discs as an optional installation configurable and installable by means of the Control Panel, and then a standard component of Windows 98 and subsequent and Windows NT 4.0 Build 1381 and by means of Service Pack 4. WSH is also a means of automation for Internet Explorer via the installed WSH engines from IE Version 3.0 onwards; at this, time VBScript became a means of automation for Microsoft Outlook 97. WSH is also an optional install provided with a VBScript and JScript engine for Windows CE 3.0 and following; some third-party engines, including Rexx and other forms of BASIC, are also available.
It is language-independent in that it can make use of different Active Scripting language engines. By default, it interprets and runs plain-text JScript and VBScript.
Users can install different scripting engines to enable them to script in other languages, for instance PerlScript. The language-independent filename extension WSF can also be used. The advantage of the Windows Script File is that it allows multiple scripts as well as a combination of scripting languages within a single file.
WSH engines include various implementations for the Rexx, ooRexx, BASIC, Perl, Ruby, Tcl, PHP, JavaScript, Delphi, Python, XSLT, and other languages.
Windows Script Host is distributed and installed by default on Windows 98 and later versions of Windows. It is also installed if Internet Explorer 5 is installed. Beginning with Windows 2000, the Windows Script Host became available for use with user login scripts.
Usage
Windows Script Host may be used for a variety of purposes, including logon scripts, administration and general automation. Microsoft describes it as an administration tool. WSH provides an environment for scripts to run – it invokes the appropriate script engine and provides a set of services and objects for the script to work with. These scripts may be run in GUI mode or command line mode, or from a COM object, offering flexibility to the user for interactive or non-interactive scripts. Windows Management Instrumentation is also scriptable by this means.WSH, the engines, and related functionality are also listed as objects which can be accessed and scripted and queried by means of the VBA and Visual Studio object explorers and those for similar tools like the various script debuggers, e.g. Microsoft Script Debugger, and editors.
WSH implements an object model which exposes a set of Component Object Model interfaces. So in addition to ASP, IIS, Internet Explorer, CScript and WScript, WSH can be used to automate and communicate with any Windows application with COM and other exposed objects, such as using PerlScript to query Microsoft Access by various means including various ODBC engines and SQL, ooRexxScript to create what are in effect Rexx macros in Microsoft Excel, Quattro Pro, Microsoft Word, Lotus Notes and any of the like, the XLNT script to get environment variables and print them in a new TextPad document, and so on.
The VBA functionality of Microsoft Office, Open Office and Corel WordPerfect Office is separate from WSH engines although Outlook 97 uses VBScript rather than VBA as its macro language.
Python in the form of ActiveState PythonScript can be used to automate and query the data in SecureCRT, as with other languages with installed engines, e.g. PerlScript, ooRexxScript, PHPScript, RubyScript, LuaScript, XLNT and so on. One notable exception is Paint Shop Pro, which can be automated in Python by means of a macro interpreter within the PSP programme itself rather than using the PythonScript WSH engine or an external Python implementation such as Python interpreters supplied with Unix emulation and integration software suites or other standalone Python implementations et al. as an intermediate and indeed can be programmed like this even in the absence of any third-party Python installation; the same goes for the Rexx-programmable terminal emulator Passport. The SecureCRT terminal emulator, SecureFX FTP client, and related client and server programmes from Van Dyke are as of the current versions automated by means of WSH so any language with an installed engine may be used; the software comes with VBScript, JScript, and PerlScript examples.
As of the most recent releases and going back a number of versions now, the programmability of 4NT / Take Command in the latest implementations generally uses the WSH engine. The ZOC terminal emulator gets its ability to be programmed in Rexx by means of an external interpreter, one of which is supplied with the programme, and alternate Rexx interpreters can be specified in the configuration of the programme. The MKS Toolkit provides PScript, a WSH engine in addition to the standard Perl interpreter perl.exe which comes with the package.
VBScript, JScript, and some third-party engines have the ability to create and execute scripts in an encoded format which prevents editing with a text editor; the file extensions for these encoded scripts is and and others of that type.
Unless otherwise specified, any WSH scripting engine can be used with the various Windows server software packages to provide CGI scripting. The current versions of the default WSH engines and all or most of the third-party engines have socket abilities as well; as a CGI script or otherwise, PerlScript is the choice of many programmers for this purpose and the VBScript and various Rexx-based engines are also rated as sufficiently powerful in connectivity and text-processing abilities to also be useful. This also goes for file access and processing—the earliest WSH engines for VBScript and JScript do not since the base language did not, whilst PerlScript, ooRexxScript, and the others have this from the beginning.
WinWrap Basic, SaxBasic and others are similar to Visual Basic for Applications, These tools are used to add scripting and macro abilities to software being developed and can be found in earlier versions of Host Explorer for example. Many other languages can also be used in this fashion. Other languages used for scripting of programmes include Rexx, Tcl, Perl, Python, Ruby, and others which come with methods to control objects in the operating system and the spreadsheet and database programmes. One exception is that the Zoc terminal emulator is controlled by a Rexx interpreter supplied with the package or another interpreter specified by the user; this is also the case with the Passport emulator.
VBScript is the macro language in Microsoft Outlook 97, whilst WordBasic is used for Word up to 6, PowerPoint and other tools. Excel to 5.0 uses Visual Basic 5.0. In Office 2000 forward, true Visual Basic for Applications 6.0 is used for all components. Other components use Visual Basic for Applications. OpenOffice uses Visual Basic, Python, and several others as macro languages and others can be added. LotusScript is very closely related to VBA and used for Lotus Notes and Lotus SmartSuite, which includes Lotus Word Pro, Lotus Approach, Lotus FastSite, Lotus 1-2-3, &c, and pure VBA, licensed from Microsoft, is used in Corel products such as WordPerfect, Paradox, Quattro Pro &c.
Any scripting language installed under Windows can be accessed by external means of PerlScript, PythonScript, VBScript and the other engines available can be used to access databases and spreadsheets and other tools like word processors, terminal emulators, command shells and so on. This can be accomplished by means of WSH, so any language can be used if there is an installed engine.
In recent versions of the Take Command enhanced command prompt and tools, the "script" command typed at the shell prompt will produce a list of the currently installed engines, one to a line and therefore CR-LF delimited.
Examples
The first example is very simple; it shows some VBScript which uses the root WSH COM object "WScript" to display a message with an 'OK' button. Upon launching this script the CScript or WScript engine would be called and the runtime environment provided.Content of a file
hello0.vbsWScript.Echo "Hello world"
WScript.Quit
WSH programming can also use the JScript language.
Content of a file
hello1.jsWScript.Echo;
WScript.Quit;
Or, code can be mixed in one WSF file, such as VBScript and JScript, or any other:
Content of a file
hello2.wsfSecurity concerns
Windows applications and processes may be automated using a script in Windows Script Host. Viruses and malware could be written to exploit this ability. Thus, some suggest disabling it for security reasons. Alternatively, antivirus programs may offer features to control.vbs and other scripts which run in the WSH environment.Since version 5.6 of WSH, scripts can be digitally signed programmatically using the Scripting.Signer object in a script itself, provided a valid certificate is present on the system. Alternatively, the signcode tool from the Platform SDK, which has been extended to support WSH filetypes, may be used at the command line.
By using Software Restriction Policies introduced with Windows XP, a system may be configured to execute only those scripts which are stored in trusted locations, have a known MD5 hash, or have been digitally signed by a trusted publisher, thus preventing the execution of untrusted scripts.