From 29dfec52946a038ba85cae45ed06ad28eacb13cc Mon Sep 17 00:00:00 2001
From: "Pedro F. Giffuni" <pfg@FreeBSD.org>
Date: Tue, 28 Feb 2017 20:50:49 +0000
Subject: [PATCH] dc(1): Introduce e command, equivalent to p, but writes to
 stderr

Obtained from:	OpenBSD
MFC after:	2 weeks
---
 usr.bin/dc/bcode.c | 14 ++++++++++++++
 usr.bin/dc/dc.1    |  6 +++++-
 2 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/usr.bin/dc/bcode.c b/usr.bin/dc/bcode.c
index 2834e4f2b1c..e6a980e4ac2 100644
--- a/usr.bin/dc/bcode.c
+++ b/usr.bin/dc/bcode.c
@@ -69,6 +69,7 @@ static __inline struct number	*pop_number(void);
 static __inline char	*pop_string(void);
 static __inline void	 clear_stack(void);
 static __inline void	 print_tos(void);
+static void		 print_err(void);
 static void		 pop_print(void);
 static void		 pop_printn(void);
 static __inline void	 print_stack(void);
@@ -198,6 +199,7 @@ static const struct jump_entry jump_table_data[] = {
 	{ 'a',	to_ascii	},
 	{ 'c',	clear_stack	},
 	{ 'd',	dup		},
+	{ 'e',	print_err	},
 	{ 'f',	print_stack	},
 	{ 'i',	set_ibase	},
 	{ 'k',	set_scale	},
@@ -507,6 +509,18 @@ print_tos(void)
 		warnx("stack empty");
 }
 
+static void
+print_err(void)
+{
+	struct value *value = tos();
+	if (value != NULL) {
+		print_value(stderr, value, "", bmachine.obase);
+		(void)putc('\n', stderr);
+	}
+	else
+		warnx("stack empty");
+}
+
 static void
 pop_print(void)
 {
diff --git a/usr.bin/dc/dc.1 b/usr.bin/dc/dc.1
index 507bbe6777d..43ba6cf01cd 100644
--- a/usr.bin/dc/dc.1
+++ b/usr.bin/dc/dc.1
@@ -35,7 +35,7 @@
 .\"
 .\"	@(#)dc.1	8.1 (Berkeley) 6/6/93
 .\"
-.Dd April 16, 2014
+.Dd February 27, 2017
 .Dt DC 1
 .Os
 .Sh NAME
@@ -196,6 +196,10 @@ operator is a non-portable extension.
 All values on the stack are popped.
 .It Ic d
 The top value on the stack is duplicated.
+.It Ic e
+Equivalent to
+.Ic p ,
+except that the output is written to the standard error stream.
 .It Ic f
 All values on the stack are printed, separated by newlines.
 .It Ic G