add uppercase string utility function (for symmetry)

src/utils.cpp

@@ -312,7 +312,7 @@ int utils::logical(const char *file, int line, const char *str, bool do_abort, L
       lmp->error->all(file, line, msg);
   }
 
-  // convert to ascii and lowercase
+  // convert to ascii
   std::string buf(str);
   if (has_utf8(buf)) buf = utf8_subst(buf);
 
@@ -705,6 +705,17 @@ std::string utils::lowercase(const std::string &text)
   return converted;
 }
 
+/* ----------------------------------------------------------------------
+   Return string converted to uppercase
+------------------------------------------------------------------------- */
+
+std::string utils::uppercase(const std::string &text)
+{
+  std::string converted;
+  for (auto c : text) converted += ::toupper(c);
+  return converted;
+}
+
 /* ----------------------------------------------------------------------
    Return string without leading or trailing whitespace
 ------------------------------------------------------------------------- */

src/utils.h

@@ -289,6 +289,13 @@ namespace utils {
 
   std::string lowercase(const std::string &line);
 
+  /*! Convert string to uppercase
+   *
+   * \param line  string that should be converted
+   * \return new string with all uppercase characters */
+
+  std::string uppercase(const std::string &line);
+
   /*! Trim leading and trailing whitespace. Like TRIM() in Fortran.
    *
    * \param line  string that should be trimmed