Created SC2245 (markdown)

SC2245.md

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+## -d only applies to the first expansion of this glob. Use a loop to check any/all.
+
+### Problematic code:
+
+```sh
+if [ -f ksh* ]
+then
+  echo "The file exists"
+fi
+```
+
+### Correct code:
+
+```sh
+for f in ksh*
+do
+  if [ -f "$f" ]
+  then
+    echo "Found a matching file: $f"
+  fi
+done
+```
+### Rationale:
+
+Ksh has the curious behavior of ignoring anything after an unrecognized flag to `test`/`[`, which means that file checking operators against globs will effectively apply the operator to the first expansion:
+
+```sh
+[ -f ksh* ]                              # This
+[ -f ksh93u ksh93u.tar ksh93u.tar.gz ]   # Becomes this
+[ -f ksh93u ]                            # And is interpreted like this
+```
+
+This is an issue when you have multiple matches for a glob. Instead of checking some or all, it only checks the first result and ignores the rest. To ensure that all results are considered (either to check that *any* or *all* results match the operator), use a loop explicitly.
+
+If you really only want to match the first result of the glob expansion as sorted alphabetically in the current locale, you can make this intention explicit:
+
+    matches=( ksh* )
+    if [ -f "${matches[0]}" ]
+    then
+      echo "The first result is a file"
+    fi
+
+### Exceptions:
+
+If you only care that entries exists, use `-e`. ShellCheck does not warn in this case, since all files resulting from glob expansion necessarily exist.
+
+### Related resources:
+
+* Help by adding links to BashFAQ, StackOverflow, man pages, POSIX, etc!