add changes to sqlite_ex and some new files

cat_v2.c

@@ -0,0 +1,33 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+void filecopy(FILE *, FILE *);
+
+int main(int argc, char *argv[]) {
+  FILE *file_p;
+  char *prog_name = argv[0];
+
+  if (argc == 1)
+    filecopy(stdin, stdout);
+  else
+    while (--argc > 0)
+      if ((file_p = fopen(*++argv, "r")) == NULL) {
+        fprintf(stderr, "%s: can't open: %s\n", prog_name, *argv);
+        exit(1);
+      } else {
+        filecopy(file_p, stdout);
+        fclose(file_p);
+      }
+  if (ferror(stdout)) {
+    fprintf(stderr, "%s: error writing stdout\n", prog_name);
+    exit(2);
+  }
+  exit(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);
+}