Windows – What does the @ symbol mean before a file path in Windows command prompt

atwindowswindows-command-prompt

I've noticed that powershell.exe started csc.exe with a command line like this:

"C:\Windows\Microsoft.NET\Framework64\v4.0.30319\csc.exe" /noconfig /fullpaths @"C:\Windows\TEMP\pn1kld2d.cmdline"

I've read the CSC manual page, but didn't found any clues about what that @ sign does here.

Does anyone know the purpose of this @ sign?

Best Answer

When in doubts, try inbuilt help csc.exe /help:

==> pushd "C:\Windows\Microsoft.NET\Framework64\v4.0.30319"

==> csc.exe /? | findstr /I "noconfig fullpaths C# @ (R) help"
Microsoft (R) Visual C# Compiler version 4.7.2556.0 for C# 5
This compiler is provided as part of the Microsoft (R) .NET Framework, but only
 supports language versions up to C# 5, which is no longer the latest version.
 For compilers that support newer versions of the C# programming language, see
 http://go.microsoft.com/fwlink/?LinkID=533240
                        Visual C# Compiler Options
@<file>                        Read response file for more options
/help                          Display this usage message (Short form: /?)
/noconfig                      Do not auto include CSC.RSP file
/fullpaths                     Compiler generates fully qualified paths

==>

Then, find csc.exe response file documentation:

@ (C# Compiler Options)

The @ option lets you specify a file that contains compiler options and source code files to compile.

Syntax: @response_file

Arguments: response_file A file that lists compiler options or source code files to compile.

Remarks: The compiler options and source code files will be processed by the compiler just as if they had been specified on the command line.
...

Related Topic