Al.exe (Assembly Linker)

Article
02/04/2013

Updated: April 2011

The Assembly Linker generates a file that has an assembly manifest from one or more files that are either modules or resource files. A module is a Microsoft intermediate language (MSIL) file that does not have an assembly manifest.

Note

To avoid being subject to virtualization on a Windows Vista computer, your assembly must include a win32 manifest that specifies a requested execution level. When using al.exe directly from the command line, you can either embed the manifest in a win32 resource file or else use mt.exe to append the manifest at a later stage in the build process. In Visual Studio 2008 both the C# and Visual Basic compilers automatically embed a win32 manifest into the assembly. For more information, see /win32manifest (C# Compiler Options).

This tool is automatically installed with Visual Studio and with the Windows SDK. To run the tool, we recommend that you use the Visual Studio Command Prompt or the Windows SDK Command Prompt (CMD Shell). These utilities enable you to run the tool easily, without navigating to the installation folder. For more information, see Visual Studio and Windows SDK Command Prompts.

If you have Visual Studio installed on your computer: On the taskbar, click Start, click All Programs, click Visual Studio, click Visual Studio Tools, and then click Visual Studio Command Prompt.

-or-

If you have the Windows SDK installed on your computer: On the taskbar, click Start, click All Programs, click the folder for the Windows SDK, and then click Command Prompt (or CMD Shell).
At the command prompt, type the following:

al sources options

Parameters

You can specify one or more of the following sources.

Source	Description
file[,target]	Copies the contents of file (a module) to the file name specified by target. After copying, Al.exe compiles target into an assembly.
/embed[resource]:file[,name[,private]]	Embeds the resource specified by file in the image that contains the assembly manifest; Al.exe copies the contents of file into the portable executable (PE) image. The name parameter is an internal identifier for the resource. By default, resources are public in the assembly (visible to other assemblies). Specifying private makes the resource not visible to other assemblies. If file is a .NET Framework resource file created, for example, by the Resource File Generator (Resgen.exe) or in the development environment, it can be accessed with members in the System.Resources. For more information, see ResourceManager. For all other resources, use the GetManifestResource* methods in the Assembly to access the resource at run time. If only resource files are passed to Al.exe, the output file is a satellite resource assembly.
/link[resource]:file[,name[,target[,private]]]	Links a resource file to an assembly. The resource specified by file becomes part of the assembly; the file is not copied. The file parameter can be in any file format. For example, you can specify a native DLL as the file parameter. This will make the native DLL part of the assembly so that it can be installed into the global assembly cache and accessed from managed code in the assembly. You can also do this by using the /linkresource compiler option. For more information, see /linkresource (C# Compiler Options). Thename parameter is an internal identifier for the resource. The targetparameter specifies a path and file name into which Al.exe copies the file. After copying, Al.exe compiles target into an assembly. By default, resources are public in the assembly (visible to other assemblies). Specifying private makes the resource not visible to other assemblies. If file is a .NET Framework resource file created, for example, by the Resource File Generator (Resgen.exe) or in the development environment, it can be accessed with members in the System.Resources namespace. For more information, see ResourceManager. For all other resources, use the GetManifestResource * methods in the Assembly class to access the resource at run time. If only resource files are passed to Al.exe, the output file is a satellite resource assembly.

file[,target]

Copies the contents of file (a module) to the file name specified by target. After copying, Al.exe compiles target into an assembly.

/embed[resource]:file[,name[,private]]

Embeds the resource specified by file in the image that contains the assembly manifest; Al.exe copies the contents of file into the portable executable (PE) image.

The name parameter is an internal identifier for the resource. By default, resources are public in the assembly (visible to other assemblies). Specifying private makes the resource not visible to other assemblies.

If file is a .NET Framework resource file created, for example, by the Resource File Generator (Resgen.exe) or in the development environment, it can be accessed with members in the System.Resources. For more information, see ResourceManager. For all other resources, use the GetManifestResource* methods in the Assembly to access the resource at run time.

If only resource files are passed to Al.exe, the output file is a satellite resource assembly.

/link[resource]:file[,name[,target[,private]]]

Links a resource file to an assembly. The resource specified by file becomes part of the assembly; the file is not copied. The file parameter can be in any file format. For example, you can specify a native DLL as the file parameter. This will make the native DLL part of the assembly so that it can be installed into the global assembly cache and accessed from managed code in the assembly. You can also do this by using the /linkresource compiler option. For more information, see /linkresource (C# Compiler Options).

Thename parameter is an internal identifier for the resource. The targetparameter specifies a path and file name into which Al.exe copies the file. After copying, Al.exe compiles target into an assembly. By default, resources are public in the assembly (visible to other assemblies). Specifying private makes the resource not visible to other assemblies.

If file is a .NET Framework resource file created, for example, by the Resource File Generator (Resgen.exe) or in the development environment, it can be accessed with members in the System.Resources namespace. For more information, see ResourceManager. For all other resources, use the GetManifestResource * methods in the Assembly class to access the resource at run time.

If only resource files are passed to Al.exe, the output file is a satellite resource assembly.

You can specify the following options; you must specify /out.

Option	Description
/algid:id	Specifies an algorithm to hash all files in a multifile assembly except the file that contains the assembly manifest. The default algorithm is CALG_SHA1. See ALG_ID in the Platform SDK documentation for other algorithms. For the first release of the .NET Framework, only CALG_SHA1 and CALG_MD5 are valid. The hash values are stored in the file table of the assembly manifest. At installation and load time, the assembly's files are checked against their hashes. You can also specify this option as a custom attribute (AssemblyAlgorithmIdAttribute) in the source code for any module.
/base[address]:addr	Specifies the address at which a DLL will be loaded on the user's computer at run time. Applications load faster if you specify the base address of the DLLs, instead of letting the operating system relocate the DLLs in the process space.
/bugreport:filename	Creates a file (filename) that contains information for reporting bugs.
/comp[any]:text	Specifies a string for the Company field in the assembly. Place the string in double quotation marks (" ") if text contains a space. This string is a custom attribute on the assembly and is available for viewing with reflection. If you do not specify /win32res, text appears in Windows Explorer as the Company property for the file. If you specify /win32res, the company information in the specified resource file appears as the Company property in Windows Explorer. If text is an empty string (""), the Win32 Company resource appears as a single space. If you specify /win32res, /company will not affect the Win32 resource information. You can also specify this option as a custom attribute (AssemblyCompanyAttribute) in the source code for any MSIL module.
/config[uration]:text	Specifies a string for the Configuration field in the assembly. Place the string in double quotation marks (" ") if text contains a space. This string is a custom attribute on the assembly and is available for viewing with reflection. If text is an empty string, the Win32 Configuration resource appears as a single space. You can also specify this option as a custom attribute (AssemblyConfigurationAttribute) in the source code for any MSIL module.
/copy[right]:text	Specifies a string for the Copyright field in the assembly. Place the string in double quotation marks (" ") if text contains a space. This string is a custom attribute on the assembly and is available for viewing with reflection. If you do not specify /win32res, /copyright appears in Windows Explorer as the Win32 Copyright resource. If text is an empty string, the Win32 Copyright resource appears as a single space. If you specify /win32res, /copyright will not affect the Win32 resource information. You can also specify this option as a custom attribute (AssemblyCopyrightAttribute) in the source code for any MSIL module.
/c[ulture]:text	Specifies the culture string to associate with the assembly. Valid values for cultures are those defined by the Internet Requests for Comments (RFC) document 1766 titled "Tags for the Identification of Languages." Place the string in double quotation marks (" ") if text contains a space. There is no default culture string. This string is available for viewing with reflection. For information about valid text strings, see the CultureInfo. You can also specify this option as a custom attribute (AssemblyCultureAttribute) in the source code for any MSIL module.
/delay[sign][+\|-]	Specifies whether the assembly will be fully or partially signed. Use /delaysign- if you want a fully signed assembly. Use /delaysign+ if you only want to include the public key in the assembly. When you request a fully signed assembly, Al.exe hashes the file that contains the manifest (assembly metadata) and signs that hash with the private key. The resulting digital signature is stored in the file that contains the manifest. When an assembly is delay signed, Al.exe does not compute and store the signature, but just reserves space in the file so the signature can be added later. The default is /delaysign-. The /delaysign option has no effect unless used with /keyfile or /keyname. For example, using /delaysign+ enables a tester to put the assembly in the global cache. After testing, you can fully sign the assembly by including the private key in the assembly. Note Before using the Gacutil.exe (Global Assembly Cache Tool) to put a delay-signed assembly into the global cache, use the Sn.exe (Strong Name Tool) to register the assembly for verification skipping. For example, Sn.exe –Vr delaySignedAssembly. Use this only for development. You can also specify this option as a custom attribute (AssemblyDelaySignAttribute) in the source code for any MSIL module.
/descr[iption]:text	Specifies a string for the Description field in the assembly. Place the string in double quotation marks (" ") if text contains a space. This string is a custom attribute on the assembly and is available for viewing with reflection. If you do not specify /win32res, /description appears in Windows Explorer as the Win32 Comments resource. If text is an empty string, the Win32 Comments resource appears as a single space. If you specify /win32res, /description will not affect the Win32 resource information. You can also specify this option as a custom attribute (Description) in the source code for any MSIL module.
/e[vidence]:file	Embeds file in the assembly with the resource name of Security.Evidence. You cannot use Security.Evidence for regular resources.
/fileversion:version	Specifies a string for the File Version field in the assembly. This string is a custom attribute on the assembly and is available for viewing with reflection. If you do not specify /win32res, /fileversion will be used as the Win32 File Version resource. If you do not specify /fileversion, the Win32 File Version resource will be populated by the Win32 Assembly Version resource. If /win32res is specified, /fileversion does not affect the Win32 resource. You can also specify this option as a custom attribute (AssemblyFileVersionAttribute) in the source code for any MSIL module.
/flags:flags	Specifies a value for the Flags field in the assembly. Possible values for flags: 0x0000 The assembly is side-by-side compatible. 0x0010 The assembly cannot execute with other versions if they are executing in the same application domain. 0x0020 The assembly cannot execute with other versions if they are executing in the same process. 0x0030 The assembly cannot execute with other versions if they are executing on the same computer. You can also specify this option as a custom attribute (AssemblyFlagsAttribute) in the source code for any MSIL module.
/fullpaths	Causes Al.exe to use the absolute path for any files that are reported in an error message.
/help	Displays command syntax and options for the tool.
/keyf[ile]:filename	Specifies a file (filename) that contains a key pair or just a public key to sign an assembly. The compiler inserts the public key in the assembly manifest and then signs the final assembly with the private key. See the Strong Name Tool (Sn.exe) for information about generating key files and installing key pairs into key containers. If you are using delayed signing, this file will usually have the public key but not the private key. The public key (of the key pair) information appears in the .publickey field of the assembly. You can also specify this option as a custom attribute (AssemblyKeyFileAttribute) in the source code for any MSIL module. If both /keyfile and /keyname are specified (either by command-line option or by custom attribute) in the same compilation, Al.exe will first try the container specified with /keyname. If that succeeds, the assembly is signed with the information in the key container. If Al.exe does not find the key container, it will try the file specified with /keyfile. If that succeeds, the assembly is signed with the information in the key file and the key information will be installed in the key container (similar to the -i option in Sn.exe) so that on the next compilation, the /keyname option will be valid.
/keyn[ame]:text	Specifies a container that holds a key pair. This will sign the assembly (give it a strong name) by inserting a public key into the assembly manifest. Al.exe will then sign the final assembly with the private key. Use Sn.exe to generate a key pair. The key information appears in the .publickey field of the assembly. Place text in double quotation marks (" ") if there is an embedded space. You can also specify this option as a custom attribute (AssemblyKeyNameAttribute) in the source code for any MSIL module.
/main:method	Specifies the fully qualified name (class.method) of the method to use as an entry point when converting a module to an executable file.
/nologo	Suppresses the banner, or logo, displayed at the command line when you invoke Al.exe.
/out:filename	Specifies the name of the file produced by Al.exe. This is a required option.
/platform:text	Limit which platform this code can run on; must be one of x86, Itanium, x64, or anycpu (the default).
/prod[uct]:text	Specifies a string for the Product field in the assembly. Place the string in double quotation marks (" ") if text contains a space. This string is a custom attribute on the assembly and is available for viewing with reflection. If you do not specify /win32res, /product appears in Windows Explorer as the Win32 Product Name resource. If text is an empty string, the Win32 Product Name resource appears as a single space. If you specify /win32res, /product will not affect the Win32 resource information. You can also specify this option as a custom attribute (AssemblyProductAttribute) in the source code for any MSIL module.
/productv[ersion]:text	Specifies a string for the Product Version field in the assembly. Place the string in double quotation marks (" ") if text contains a space. This string is a custom attribute on the assembly and is available for viewing with reflection. If you do not specify /win32res, /productversion will be used as the Win32 Product Version resource. If you do not specify /productversion, the Win32 Product Version resource will be populated by the Win32 File Version resource. If you specify /win32res, /productversion will not affect the Win32 resource information. You can also specify this option as a custom attribute (AssemblyInformationalVersionAttribute) in the source code for any MSIL module.
/t[arget]:lib[rary] \| exe \| win[exe]	Specifies the file format of the output file: lib[rary] (code library), exe (console application), or win[exe] (Windows-based application). The default is lib[rary].
/template:filename	Specifies the assembly, filename, from which to inherit all assembly metadata, except the culture field. An assembly that you create with /template will be a satellite assembly.
/title:text	Specifies a string for the Title field in the assembly. Place the string in double quotation marks (" ") if text contains a space. This string is a custom attribute on the assembly and is available for viewing with reflection. If you do not specify /win32res, /title appears in Windows Explorer as the Win32 Description resource, which is used by the shell as the friendly name of an application. It is also displayed on the Open With submenu of the shortcut menu for a file type for which there are multiple supporting applications. If text is an empty string, the Win32 Description resource appears as a single space. If you specify /win32res, /title will not affect the Win32 resource information. You can also specify this option as a custom attribute (AssemblyTitleAttribute) in the source code for any MSIL module.
/trade[mark]:text	Specifies a string for the Trademark field in the assembly. Place the string in double quotation marks (" ") if text contains a space. This string is a custom attribute on the assembly and is available for viewing with reflection. If you do not specify /win32res, /trademark appears in Windows Explorer as the Win32 Trademark resource. If text is an empty string, the Win32 Trademark resource appears as a single space. If you specify /win32res, /trademark will not affect the Win32 resource information. You can also specify this option as a custom attribute (AssemblyTrademarkAttribute) in the source code for any MSIL module.
/v[ersion]:version	Specifies version information for this assembly. The format of the version string is major.minor.build.revision. The default value is 0. If you do specify /version, you must specify major. If you specify major and minor, you can specify an asterisk ()for build. This causes build to be equal to the number of days since January 1, 2000, local time, and revision to be equal to the number of seconds since midnight of the current day, local time, divided by 2. If you specify major, minor, and build, you can specify an asterisk for revision. This causes revision to be equal to the number of seconds since midnight of the current day, local time, divided by 2. To summarize, the valid version strings are as follows: X X.X X.X. X.X.X X.X.X.* X.X.X.X where X is any unsigned short constant except 65535 (0-65534). If you do not specify /win32res, /version will be used as the Win32 Assembly Version resource. If you do not specify /win32res, /productversion, and /fileversion, /version will be used for the Assembly Version, File Version, and Product Version Win32 resources. If you specify /win32res, /version will not affect the Win32 resource information. You can also specify this option as a custom attribute (AssemblyVersionAttribute) in the source code for any MSIL module.
/win32icon:filename	Inserts an .ico file in the assembly. The .ico file gives the output file the desired appearance in Windows Explorer.
/win32res:filename	Inserts a Win32 resource (.res file) in the output file. A Win32 resource file can be created by using the Resource Compiler. The Resource Compiler is invoked when you compile a Visual C++ program; a .res file is created from the .rc file.
@filename	Specifies a response file that contains Al.exe commands. Commands in the response file can appear one per line or on the same line, separated by one or more spaces.
/?	Displays command syntax and options for the tool.

Remarks

All Visual Studio compilers produce assemblies. However, if you have one or more modules (metadata without a manifest), you can use Al.exe to create an assembly with the manifest in a separate file.

To install assemblies in the cache, remove assemblies from the cache, or list the contents of the cache, use the Global Assembly Cache Tool (Gacutil.exe).

Example

The following command creates an executable file t2a.exe with an assembly from the t2.netmodule module. The entry point is the Main method in MyClass.

al t2.netmodule /target:exe /out:t2a.exe /main:MyClass.Main

Change History

Date	History	Reason
April 2011	Added information about using the Visual Studio and Windows SDK Command Prompts.	Information enhancement.

April 2011

Added information about using the Visual Studio and Windows SDK Command Prompts.

Information enhancement.

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Al.exe (Assembly Linker)

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Remarks

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