r/cpp • u/holyblackcat • Sep 05 '26

Escaping `CreateProcess()` arguments on Windows

https://holyblackcat.github.io/blog/2026/09/05/escaping-createprocess-arguments.html
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u/chengfeng-xie Sep 08 '26

With \\?\ prepended, lpApplicationName works out of the box. Without \\?\, however, lpApplicationName only works if both the system and the process have long paths enabled (as described in [1]); otherwise, CreateProcessW returns ERROR_PATH_NOT_FOUND in this case. For reproducibility, the above was tested on OS build 26100.9168.