From aa00959024643a33f766ef3f060a934006fe7725 Mon Sep 17 00:00:00 2001
From: Kartik Agaram <vc@akkartik.com>
Date: Sun, 23 Sep 2018 09:23:21 -0700
Subject: 4504

---
 transect/ex4.k2 | 34 ++++++++++++++++++++++++++++++++++
 1 file changed, 34 insertions(+)
 create mode 100644 transect/ex4.k2

(limited to 'transect/ex4.k2')

diff --git a/transect/ex4.k2 b/transect/ex4.k2
new file mode 100644
index 00000000..9a7ddee7
--- /dev/null
+++ b/transect/ex4.k2
@@ -0,0 +1,34 @@
+## read a character from stdin, save it to a global, write it to stdout
+
+# variables are always references
+#   read their address with their names: x (can't write to their address)
+#   read/write their contents with a lookup: *x
+var x : char
+
+fn main [
+  call read 0/stdin, x, 1/size
+  result/EAX <- call write 1/stdout, x, 1/size
+  call exit, result/EAX
+]
+
+fn read fd : int, x : (address array byte), size : int [
+  EBX <- copy fd
+  ECX <- copy x
+  EDX <- copy size
+  EAX <- copy 3/read
+  syscall
+]
+
+fn write fd : int, x : (address array byte), size : int [
+  EBX <- copy fd
+  ECX <- copy x
+  EDX <- copy size
+  EAX <- copy 4/write
+  syscall
+]
+
+fn exit x : int [
+  code/EBX <- copy x
+  code/EAX <- copy 1/exit
+  syscall
+]
-- 
cgit 1.4.1-2-gfad0