Updated to search for "cd x:"

Tested again with `libmodbus` and it works.

nimterop/build.nim

@@ -1,4 +1,4 @@
-import macros, osproc, sets, strformat, strutils, tables
+import macros, osproc, sets, strformat, strutils, regex, tables
 
 import os except findExe, sleep
 
@@ -29,13 +29,13 @@ proc execAction*(cmd: string, retry = 0, nostderr = false): string =
     ccmd = ""
     ret = 0
   when defined(Windows):
-    var filteredCmd = cmd
-    if cmd.startsWith("cd"):
-      var
-        colonIndex = cmd.find(":")
-        driveLetter = cmd.substr(colonIndex-1, colonIndex)
-      if driveLetter[0].isAlphaAscii() and driveLetter[1] == ':':
-        filteredCmd = &"{driveLetter} && {cmd}"
+    var
+      filteredCmd = cmd
+      matches: RegexMatch
+    if cmd.find(re"cd\s+(\D)\:", matches):
+      var driveLetter = cmd[matches.group(0)[0]]
+      filteredCmd = &"{driveLetter}: && {cmd}"
+      echo filteredCmd
     ccmd = "cmd /c " & filteredCmd
   elif defined(posix):
     ccmd = cmd