-char * Perl_tounixspec (pTHX_ char *, char *);
-char * Perl_tounixspec_ts (pTHX_ char *, char *);
-char * Perl_tovmsspec (pTHX_ char *, char *);
-char * Perl_tovmsspec_ts (pTHX_ char *, char *);
-char * Perl_tounixpath (pTHX_ char *, char *);
-char * Perl_tounixpath_ts (pTHX_ char *, char *);
-char * Perl_tovmspath (pTHX_ char *, char *);
-char * Perl_tovmspath_ts (pTHX_ char *, char *);
-int Perl_do_rmdir (pTHX_ char *);
-char * Perl_fileify_dirspec (pTHX_ char *, char *);
-char * Perl_fileify_dirspec_ts (pTHX_ char *, char *);
-char * Perl_pathify_dirspec (pTHX_ char *, char *);
-char * Perl_pathify_dirspec_ts (pTHX_ char *, char *);
-char * Perl_rmsexpand (pTHX_ char *, char *, char *, unsigned);
-char * Perl_rmsexpand_ts (pTHX_ char *, char *, char *, unsigned);
-int Perl_trim_unixpath (pTHX_ char *, char*, int);
-DIR * Perl_opendir (pTHX_ char *);
-int Perl_rmscopy (pTHX_ char *, char *, int);
-int Perl_my_mkdir (pTHX_ char *, Mode_t);
+char * Perl_tounixspec (pTHX_ const char *, char *);
+char * Perl_tounixspec_ts (pTHX_ const char *, char *);
+char * Perl_tovmsspec (pTHX_ const char *, char *);
+char * Perl_tovmsspec_ts (pTHX_ const char *, char *);
+char * Perl_tounixpath (pTHX_ const char *, char *);
+char * Perl_tounixpath_ts (pTHX_ const char *, char *);
+char * Perl_tovmspath (pTHX_ const char *, char *);
+char * Perl_tovmspath_ts (pTHX_ const char *, char *);
+int Perl_do_rmdir (pTHX_ const char *);
+char * Perl_fileify_dirspec (pTHX_ const char *, char *);
+char * Perl_fileify_dirspec_ts (pTHX_ const char *, char *);
+char * Perl_pathify_dirspec (pTHX_ const char *, char *);
+char * Perl_pathify_dirspec_ts (pTHX_ const char *, char *);
+char * Perl_rmsexpand (pTHX_ const char *, char *, const char *, unsigned);
+char * Perl_rmsexpand_ts (pTHX_ const char *, char *, const char *, unsigned);
+int Perl_trim_unixpath (pTHX_ char *, const char*, int);
+DIR * Perl_opendir (pTHX_ const char *);
+int Perl_rmscopy (pTHX_ const char *, const char *, int);
+int Perl_my_mkdir (pTHX_ const char *, Mode_t);