From ada378e290e7f0ec8883878d0aeaef2c62571920 Mon Sep 17 00:00:00 2001
From: "Peter J. Holzer" <hjp@hjp.at>
Date: Fri, 21 Jul 2017 12:15:15 +0200
Subject: [PATCH] Add functions sin, cos, tan, exp and constant e

---
 rpn | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/rpn b/rpn
index 927db1f..e8ed2f4 100755
--- a/rpn
+++ b/rpn
@@ -43,6 +43,20 @@ while (<>) {
 	} elsif (m{^ld$}) {
 	    my $x = pop @stack;
 	    push @stack, log($x) / log(2);
+	} elsif (m{^sin$}) {
+	    my $x = pop @stack;
+	    push @stack, sin($x);
+	} elsif (m{^cos$}) {
+	    my $x = pop @stack;
+	    push @stack, cos($x);
+	} elsif (m{^tan$}) {
+	    my $x = pop @stack;
+	    push @stack, tan($x);
+	} elsif (m{^e$}) {
+	    push @stack, exp(1);
+	} elsif (m{^exp$}) {
+            my $x = pop @stack;
+	    push @stack, exp($x);
 	} elsif (m{^0x[0-9a-fA-F]+$}) {
             no warnings 'portable';
 	    push @stack, hex($_);