no-op.c is an useless shell filter

code/no-op.c

@@ -0,0 +1,18 @@
+/*
+ *	no-op.c is an useless shell filter
+ */
+#include  <stdio.h>
+#include  <ctype.h>
+
+int main(int argc, char *argv[])
+{
+int	quux, baz;
+
+while (EOF != (quux=getchar())) {
+	baz = toupper(quux);
+	if ('O'==baz || 'P'==baz) continue;
+	putchar(quux);
+	}
+
+return 0;
+}