mescc: Mes C Library: Support GNU Awk: Add isgraph.

* lib/ctype/isgraph.c: New file.
* lib/libc+gnu.c: Include it.
* include/ctype.h: Add missing prototypes.

include/ctype.h

@@ -29,11 +29,23 @@
 
 #else // ! WITH_GLIBC
 #include <endian.h>
+
+int isalnum (int c);
 int isalpha (int c);
 int isascii (int c);
+int iscntrl (int c);
 int isdigit (int c);
-int isxdigit (int c);
+int isgraph (int c);
+int islower (int c);
+int isnumber (int c, int base);
+int isprint (int c);
+int ispunct (int c);
 int isspace (int c);
+int isupper (int c);
+int isxdigit (int c);
+int tolower (int c);
+int toupper (int c);
+
 #endif // ! WITH_GLIBC
 
 #endif // __MES_CTYPE_H

lib/ctype/isgraph.c

@@ -0,0 +1,27 @@
+/* -*-comment-start: "//";comment-end:""-*-
+ * GNU Mes --- Maxwell Equations of Software
+ * Copyright © 2019 Jan (janneke) Nieuwenhuizen <janneke@gnu.org>
+ *
+ * This file is part of GNU Mes.
+ *
+ * GNU Mes is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or (at
+ * your option) any later version.
+ *
+ * GNU Mes is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with GNU Mes.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <ctype.h>
+
+int
+isgraph (int c)
+{
+  return c > 32 && c < 127;
+}

lib/libc+gnu.c

@@ -120,5 +120,8 @@
 #include <stub/sigdelset.c>
 #include <stub/ttyname.c>
 
+// gawk
+#include <ctype/isgraph.c>
+
 // tar
 #include <posix/execlp.c>