TST: Move the DLL checker to a separate script

Instead of trying to write it every run, just add it to the repository and use that. I'm not sure how Windows git handles line endings; I suspect it changes things to \r\n, which is not what I want. I'm on Cygwin, not MSYS, so everything expects \n.
numpy · charris · Jul 21, 2021 · Feb 4, 2021 · Apr 15, 2021 · Apr 25, 2021
commit 2d905c3114713da11cbead5588b1d4f9537c1750
diff --git a/.github/workflows/cygwin.yml b/.github/workflows/cygwin.yml
@@ -63,31 +63,5 @@ jobs:
         run: |
           dash -c "/usr/bin/python3.7 -m pip show numpy"
           dash -c "/usr/bin/python3.7 -m pip show -f numpy | grep .dll"
-          echo >list_dlls_dos.sh '#!/bin/dash
-          site_packages=$(python3.7 -m pip show numpy | \
-              grep Location | cut -d " " -f 2 -);
-          dll_list=$(for name in $(python3.7 -m pip show -f numpy | \
-              grep -F .dll); do echo ${site_packages}/${name}; done)
-          echo "Checks for existence, permissions and file type"
-          ls -l ${dll_list}
-          file ${dll_list}
-          echo "Dependency checks"
-          ldd ${dll_list} | grep -F -e " => not found" && exit 1
-          cygcheck ${dll_list} >cygcheck_dll_list 2>cygcheck_missing_deps
-          grep -F -e "cygcheck: track_down: could not find " cygcheck_missing_deps && exit 1
-          echo "Import tests"
-          mkdir -p dist/
-          cd dist/
-          for name in ${dll_list};
-          do
-              echo ${name}
-              ext_module=$(echo ${name} | \
-                  sed -E \
-                      -e "s/^\/+(home|usr).*?site-packages\/+//" \
-                      -e "s/.cpython-3.m?-x86(_64)?-cygwin.dll$//" \
-                      -e "s/\//./g")
-              python3.7 -c "import ${ext_module}"
-          done
-          '
-          dash -c "/bin/tr -d '\r' <list_dlls_dos.sh >list_dlls_unix.sh"
+          dash -c "/bin/tr -d '\r' <tools/list_installed_dll_dependencies_cygwin.sh >list_dlls_unix.sh"
           dash "list_dlls_unix.sh"
diff --git a/tools/list_installed_dll_dependencies_cygwin.sh b/tools/list_installed_dll_dependencies_cygwin.sh
@@ -0,0 +1,38 @@
+#!/bin/dash
+# Check permissions and dependencies on installed DLLs
+# DLLs need execute permissions to be used
+# DLLs must be able to find their dependencies
+# This checks both of those, then does a direct test
+# The best way of checking whether a C extension module is importable
+# is trying to import it.  The rest is trying to give reasons why it
+# isn't importing.
+#
+# One of the tools and the extension for shared libraries are
+# Cygwin-specific, but the rest should work on most platforms with
+# /bin/sh
+
+py_ver=3.7
+site_packages=$(python${py_ver} -m pip show numpy | \
+		    grep Location | cut -d " " -f 2 -);
+dll_list=$(for name in $(python${py_ver} -m pip show -f numpy | \
+			     grep -F .dll); do echo ${site_packages}/${name}; done)
+echo "Checks for existence, permissions and file type"
+ls -l ${dll_list}
+file ${dll_list}
+echo "Dependency checks"
+ldd ${dll_list} | grep -F -e " => not found" && exit 1
+cygcheck ${dll_list} >cygcheck_dll_list 2>cygcheck_missing_deps
+grep -F -e "cygcheck: track_down: could not find " cygcheck_missing_deps && exit 1
+echo "Import tests"
+mkdir -p dist/
+cd dist/
+for name in ${dll_list};
+do
+    echo ${name}
+    ext_module=$(echo ${name} | \
+                     sed -E \
+			 -e "s/^\/+(home|usr).*?site-packages\/+//" \
+			 -e "s/.cpython-3.m?-x86(_64)?-cygwin.dll$//" \
+			 -e "s/\//./g")
+    python${py_ver} -c "import ${ext_module}"
+done