This article discusses the limitation to the length of the
strings that you use from the command prompt in Command Prompt (Cmd.exe) and
the methods that you can use to work around this limitation.
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On computers running Microsoft Windows XP or later, the
maximum length of the string that you can use at the command prompt is 8191
characters. On computers running Microsoft Windows 2000 or Windows NT 4.0, the
maximum length of the string that you can use at the command prompt is 2047
characters.
This limitation applies to the command line, individual
environment variables (such as the PATH variable) that are inherited by other
processes, and all environment variable expansions. If you use Command Prompt
to run batch files, this limitation also applies to batch file processing.
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Examples
The following list gives you some examples of how this limitation
applies to commands that you run in Command Prompt and commands that you use in
a batch file.
| • | In Command Prompt, the total length of the following
command line that you use at the command prompt cannot contain more than either
2047 or 8191 characters (as appropriate to your operating system): cmd.exe /k ExecutableFile.exe parameter1, parameter2 ... parameterN |
| • | In a batch file, the total length of the following command
line that you use in the batch file cannot contain more than either 2047 or
8191 characters (as appropriate to your operating system): cmd.exe /k ExecutableFile.exe parameter1, parameter2 ... parameterN This limitation applies to command lines that are
contained in batch files when you use Command Prompt to run the batch
file. |
| • | In Command Prompt, the total length of
EnvironmentVariable1 after you expand
EnvironmentVariable2 and
EnvironmentVariable3 cannot contain more than either
2047 or 8191 characters (as appropriate to your operating system): c:> set EnvironmentVariable1=EnvironmentVariable2EnvironmentVariable3 |
| • | In a batch file, the total length of the following command
line after you expand the environment variables in the command line cannot
contain more than either 2047 or 8191 characters (as appropriate to your
operating system): ExecutableFile.exe parameter1parameter2 |
| • | Even though the Win32 limitation for environment variables
is 32,767 characters, Command Prompt ignores any environment variables that are
inherited from the parent process and are longer than its own limitations of
either 2047 or 8191 characters (as appropriate to the operating system). For
more information about the SetEnvironmentVariable function, visit the following Microsoft Web site: |
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How to work around the limitation
To work around the limitation, use one or more of the following
methods (as appropriate to your situation):
| • | Modify programs that require long command lines so that
they use a file that contains the parameter information, and then include the
name of the file in the command line.
For example, instead of using
the ExecutableFile.exe Parameter1 Parameter2 ...ParameterN command line in a batch file, modify the program to use a command
line that is similar to the following command line, where
ParameterFile is a file that contains the required
parameters (parameter1 parameter2
...ParameterN):ExecutableFile.exe c:\temp\ParameterFile.txt |
| • | Modify programs that use large environment variables so
that the environment variables contain less than either 2047 or 8191 characters
(as appropriate to your operating system).
For example, if the PATH
environment variable contains more than either 2047 or 8191 characters (as
appropriate to your operating system), use one or more of the following methods
to reduce the number of characters:
| • | Use shorter names for folders and files. | | • | Reduce the depth of folder trees. | | • | Store files in fewer folders so that fewer folders are
required in the PATH environment variable. | | • | Investigate possible methods that you can use to
reduce the dependency of PATH for locating .dll files. |
|
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