StringBuilder is not required in CreateProcess* about vanara

[dahall]

It will really help if you provide more context so I don't have to assume your intent. Here, I assume you're talking about the lpCommandLine parameter. If so, then it does need to be a StringBuilder per its documented use:
"The Unicode version of this function, CreateProcessW, can modify the contents of this string. Therefore, this parameter cannot be a pointer to read-only memory (such as a const variable or a literal string). If this parameter is a constant string, the function may cause an access violation."

[NN---]

Sorry, forgot to put the link.
Yes I am talking about CreateProcess.
It is okay to pass string, since .NET marshaller always copies the string, so it is can be freely modified without touching the original one.

[dahall]

Correct, but then that copied string is not available to the developer. Using StringBuilder allows the developer to see the changes made by the function.

[NN---]

CreateProcess doesn't make any visible effect to caller.
It just changes string internally and then restores it to original.

[NN---]

https://blogs.msdn.microsoft.com/oldnewthing/20090601-00/?p=18083
The CreateProcess temporarily modifies the string you pass as the lpCommandLine in its attempt to figure out where the program name ends and the command line arguments begin.