From 36a526a95b83d05ce45ba6dd8fc52b436b94c8db Mon Sep 17 00:00:00 2001
From: hellerve <veit@veitheller.de>
Date: Tue, 10 Oct 2017 16:30:00 +0200
Subject: [PATCH] make it so

---
 README.md   | 15 +++++++++++++++
 main.c      | 11 +++++++++++
 observe.sh  | 15 +++++++++++++++
 src/morse.c | 13 +++++++++++++
 src/morse.h |  5 +++++
 5 files changed, 59 insertions(+)
 create mode 100644 README.md
 create mode 100644 main.c
 create mode 100755 observe.sh
 create mode 100644 src/morse.c
 create mode 100644 src/morse.h

diff --git a/README.md b/README.md
new file mode 100644
index 0000000..d41a4e8
--- /dev/null
+++ b/README.md
@@ -0,0 +1,15 @@
+# morse
+
+Morse Code through CPU utilization.
+
+## Usage
+
+The API exposes two simple functions, `dit` and `dah`. `dit` will utilize the
+CPU for a second, `dah` will sleep. Knowing this, we can exchange information
+by looking at the program’s CPU utilization every second. A simple POC is
+included in `main.c` and `observe.sh`. It’s really, really crude. For best
+results, compile without optimizations.
+
+<hr/>
+
+Have fun!
diff --git a/main.c b/main.c
new file mode 100644
index 0000000..410de3d
--- /dev/null
+++ b/main.c
@@ -0,0 +1,11 @@
+#include "morse.h"
+
+int main() {
+  dit();
+  dah();
+  dit();
+  dit();
+  dah();
+  dit();
+  return 0;
+}
diff --git a/observe.sh b/observe.sh
new file mode 100755
index 0000000..0d9574c
--- /dev/null
+++ b/observe.sh
@@ -0,0 +1,15 @@
+PID=$1
+RET=0
+
+while [ "$RET" == 0 ]; do
+  INP=`ps -o pcpu -p $PID`
+  RET=$?
+  ARR=($INP)
+  echo ${ARR[1]}
+  if [ `echo "${ARR[1]}"'>'50 | bc -l` == 1 ]; then
+    echo dit
+  else
+    echo dah
+  fi
+  sleep 1
+done
diff --git a/src/morse.c b/src/morse.c
new file mode 100644
index 0000000..d30db32
--- /dev/null
+++ b/src/morse.c
@@ -0,0 +1,13 @@
+#include "morse.h"
+
+void dit() {
+  time_t t0, t1;
+  time(&t0);
+  t1 = t0;
+
+  while(difftime(t1, t0) < 1) time(&t1);
+}
+
+void dah() {
+  sleep(1);
+}
diff --git a/src/morse.h b/src/morse.h
new file mode 100644
index 0000000..489162c
--- /dev/null
+++ b/src/morse.h
@@ -0,0 +1,5 @@
+#include <time.h>
+#include <unistd.h>
+
+void dit();
+void dah();