compress files

concurrency/compressfiles/exampledata/example1.txt

@@ -0,0 +1,2 @@
+
+example1

concurrency/compressfiles/exampledata/example2.txt

@@ -0,0 +1 @@
+example2

concurrency/compressfiles/exampledata/example3.txt

@@ -0,0 +1 @@
+example3

concurrency/compressfiles/exampledata/example4.txt

@@ -0,0 +1 @@
+example4

concurrency/compressfiles/main.go

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+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
+}