Is there anything that displays line numbers for all files open in Visual Studio?
In VS 2010, just for text ...
Tools -> Options -> Text Editor -> Plain Text -> General -> Display Line Numbers
For everything...
Tools -> Options -> Text Editor -> All Languages -> General -> Display Line Numbers
Go to the following path:
Tools → Options → Text Editors → All Languages
Now check the Line Number option
And here you go!
→ → → . " "
It depends on your version of Visual Studio, but in VS2012 you should go to TOOLS → Options → Text Editor → Plain Text, then you should check the “Linear numbers” box under the heading “Display”.