From 07112012a19f2f8bfeac01830729f28862b16f1d Mon Sep 17 00:00:00 2001
From: Jian Han <jianhan@mail.com>
Date: Mon, 1 Jan 2018 22:07:44 +1000
Subject: [PATCH] compress files

---
 .../compressfiles/exampledata/example1.txt    |  2 +
 .../compressfiles/exampledata/example2.txt    |  1 +
 .../compressfiles/exampledata/example3.txt    |  1 +
 .../compressfiles/exampledata/example4.txt    |  1 +
 concurrency/compressfiles/main.go             | 41 +++++++++++++++++++
 5 files changed, 46 insertions(+)
 create mode 100644 concurrency/compressfiles/exampledata/example1.txt
 create mode 100644 concurrency/compressfiles/exampledata/example2.txt
 create mode 100644 concurrency/compressfiles/exampledata/example3.txt
 create mode 100644 concurrency/compressfiles/exampledata/example4.txt
 create mode 100644 concurrency/compressfiles/main.go

diff --git a/concurrency/compressfiles/exampledata/example1.txt b/concurrency/compressfiles/exampledata/example1.txt
new file mode 100644
index 0000000..61f77c3
--- /dev/null
+++ b/concurrency/compressfiles/exampledata/example1.txt
@@ -0,0 +1,2 @@
+
+example1
\ No newline at end of file
diff --git a/concurrency/compressfiles/exampledata/example2.txt b/concurrency/compressfiles/exampledata/example2.txt
new file mode 100644
index 0000000..b7d9bb0
--- /dev/null
+++ b/concurrency/compressfiles/exampledata/example2.txt
@@ -0,0 +1 @@
+example2
\ No newline at end of file
diff --git a/concurrency/compressfiles/exampledata/example3.txt b/concurrency/compressfiles/exampledata/example3.txt
new file mode 100644
index 0000000..eedfd49
--- /dev/null
+++ b/concurrency/compressfiles/exampledata/example3.txt
@@ -0,0 +1 @@
+example3
\ No newline at end of file
diff --git a/concurrency/compressfiles/exampledata/example4.txt b/concurrency/compressfiles/exampledata/example4.txt
new file mode 100644
index 0000000..2f7eee0
--- /dev/null
+++ b/concurrency/compressfiles/exampledata/example4.txt
@@ -0,0 +1 @@
+example4
\ No newline at end of file
diff --git a/concurrency/compressfiles/main.go b/concurrency/compressfiles/main.go
new file mode 100644
index 0000000..bdbd568
--- /dev/null
+++ b/concurrency/compressfiles/main.go
@@ -0,0 +1,41 @@
+package main
+
+import (
+	"compress/gzip"
+	"fmt"
+	"io"
+	"os"
+	"sync"
+)
+
+func main() {
+	var wg sync.WaitGroup
+	var i int = -1
+	var file string
+	for i, file = range os.Args[1:] {
+		wg.Add(1)
+		go func(filename string) {
+			compress(filename)
+			wg.Done()
+		}(file)
+	}
+	wg.Wait()
+	fmt.Printf("Compressed %d files\n", i+1)
+}
+func compress(filename string) error {
+	// Unchanged from above
+	in, err := os.Open(filename)
+	if err != nil {
+		return err
+	}
+	defer in.Close()
+	out, err := os.Create(filename + ".gz")
+	if err != nil {
+		return err
+	}
+	defer out.Close()
+	gzout := gzip.NewWriter(out)
+	_, err = io.Copy(gzout, in)
+	gzout.Close()
+	return err
+}