Using subst to Shorten Paths

Solution: Map a Folder to a Drive with subst

Problem: see 01_problem_path_length.

Fix

Windows includes the subst command, which maps a folder to a drive letter. Once mapped, the drive letter acts as a short alias for the folder, so every path under it is shorter by the length of the original folder path.

Example

Map the folder D:\eCode to the drive letter E::

subst E: D:\eCode

After this, E:\ behaves like the root of D:\eCode. A file at D:\eCode\project\src\main.c can be reached as E:\project\src\main.c, which is shorter and stays under the Windows path limit for tools that struggle with long paths.

subst mappings are per session. They disappear on reboot or sign-out. To make the mapping return automatically, see 03_howto_persist_subst.

To remove a mapping, run subst E: /D.