add changes to sqlite_ex and some new files

cat_v1.c

@@ -0,0 +1,27 @@
+#include <stdio.h>
+
+void filecopy(FILE *, FILE *);
+
+int main(int argc, char *argv[]) {
+  FILE *file_p;
+
+  if (argc == 1)
+    filecopy(stdin, stdout);
+  else
+    while (--argc > 0)
+      if ((file_p = fopen(*++argv, "r")) == NULL) {
+        printf("cat: can't open: %s\n", *argv);
+        return 1;
+      } else {
+        filecopy(file_p, stdout);
+        fclose(file_p);
+      }
+  return 0;
+}
+
+void filecopy(FILE* in_file_p, FILE* out_file_p) {
+  int ch;
+
+  while((ch = getc(in_file_p)) != EOF)
+    putc(ch, out_file_p);
+}