1 files changed, 81 insertions, 0 deletions
diff --git a/src/tutorial/funcs.c b/src/tutorial/funcs.c
new file mode 100644
index 00000000000..71371f51609
--- /dev/null
+++ b/src/tutorial/funcs.c
@@ -0,0 +1,81 @@
+/******************************************************************************
+  These are user-defined functions that can be bound to a Postgres backend
+  and called by Postgres to execute SQL functions of the same name.
+
+  The calling format for these functions is defined by the CREATE FUNCTION
+  SQL statement that binds them to the backend.
+*****************************************************************************/
+
+#include <string.h>
+#include <stdio.h>
+#include "postgres.h"			/* for char16, etc. */
+#include "utils/palloc.h"		/* for palloc */
+#include "libpq-fe.h"			/* for TUPLE */
+#include "executor/executor.h"	/* for GetAttributeByName() */
+
+/* The following prototypes declare what we assume the user declares to
+   Postgres in his CREATE FUNCTION statement.
+*/
+
+int			add_one(int arg);
+char16	   *concat16(char16 *arg1, char16 *arg2);
+text	   *copytext(text *t);
+
+bool
+c_overpaid(TUPLE t,				/* the current instance of EMP */
+		   int4 limit);
+
+
+
+int
+add_one(int arg)
+{
+	return (arg + 1);
+}
+
+char16 *
+concat16(char16 *arg1, char16 *arg2)
+{
+	char16	   *new_c16 = (char16 *) palloc(sizeof(char16));
+
+	MemSet(new_c16, 0, sizeof(char16));
+	strncpy((char *) new_c16, (char *) arg1, 16);
+	return (char16 *) (strncat((char *) new_c16, (char *) arg2, 16));
+}
+
+text *
+copytext(text *t)
+{
+
+	/*
+	 * VARSIZE is the total size of the struct in bytes.
+	 */
+	text	   *new_t = (text *) palloc(VARSIZE(t));
+
+	MemSet(new_t, 0, VARSIZE(t));
+
+	VARSIZE(new_t) = VARSIZE(t);
+
+	/*
+	 * VARDATA is a pointer to the data region of the struct.
+	 */
+	memcpy((void *) VARDATA(new_t),		/* destination */
+		   (void *) VARDATA(t), /* source */
+		   VARSIZE(t) - VARHDRSZ);		/* how many bytes */
+
+	return (new_t);
+}
+
+bool
+c_overpaid(TUPLE t,				/* the current instance of EMP */
+		   int4 limit)
+{
+	bool		isnull = false;
+	int4		salary;
+
+	salary = (int4) GetAttributeByName(t, "salary", &isnull);
+
+	if (isnull)
+		return (false);
+	return (salary > limit);
+}