From: AceVest <zhaoyanbai@126.com>
Date: Sun, 18 Jun 2017 15:27:33 +0000 (+0800)
Subject: ....
X-Git-Url: http://zhaoyanbai.com/repos/%22http:/www.isc.org/icons/man.dnssec-checkds.html?a=commitdiff_plain;h=e79b092e3ef52922308b46026c880f80e429db2d;p=acecode.git

....
---

diff --git a/learn/go/exercise/1.5.go b/learn/go/exercise/1.5.go
new file mode 100644
index 0000000..8a4df42
--- /dev/null
+++ b/learn/go/exercise/1.5.go
@@ -0,0 +1,107 @@
+/*
+ * ------------------------------------------------------------------------
+ *   File Name: 1.5.go
+ *      Author: Zhao Yanbai
+ *              2017-06-11 16:09:11 Sunday CST
+ * Description: none
+ * ------------------------------------------------------------------------
+ */
+package main
+import (
+//	"fmt"
+	"image"
+	"image/color"
+	"image/gif"
+	"io"
+	"math"
+	"math/rand"
+	"os"
+)
+
+var palette = []color.Color {
+	color.White,
+	color.Black,
+	color.RGBA{0xFF, 0x00, 0x00, 0xFF},
+	color.RGBA{0x00, 0xFF, 0x00, 0xFF},
+	color.RGBA{0x00, 0x00, 0xFF, 0xFF},
+}
+
+const (
+	lineColorIndex = 3
+)
+
+
+func lissajous(out io.Writer) {
+	const (
+		cycles		= 5
+		res			= 0.001
+		size		= 100
+		nframes		= 128
+		delay		= 8		// 80ms
+	)
+
+	freq := rand.Float64() * 3.0
+	anim := gif.GIF{LoopCount: nframes}
+	phase := 0.0
+
+	for i := 0; i<nframes; i++ {
+		rect := image.Rect(0, 0, 2*size+1, 2*size+1)
+		img := image.NewPaletted(rect, palette)
+		for t := 0.0; t<2*math.Pi*cycles; t += res {
+			x := math.Sin(t)
+			y := math.Sin(t*freq + phase)
+			img.SetColorIndex(size+int(x*size+0.5), size+int(y*size+0.5), lineColorIndex)
+		}
+		phase += 0.1
+		anim.Delay = append(anim.Delay, delay)
+		anim.Image = append(anim.Image, img)
+	}
+
+	gif.EncodeAll(out, &anim)
+}
+
+func sint(out io.Writer) {
+	const (
+		cycles		= 5
+		res			= 0.001
+		size		= 100
+		nframes		= 24
+		delay		= 8		// 80ms
+	)
+
+	anim := gif.GIF{LoopCount: nframes}
+
+	for i := 0; i<nframes; i++ {
+		rect := image.Rect(0, 0, 2*size+1, 2*size+1)
+		img := image.NewPaletted(rect, palette)
+
+		bgn := float64(i)
+		for t := bgn; t<bgn+3.5*math.Pi; t += res {
+			x := t
+			y := math.Sin(t)
+			delta := t - bgn
+			colorIndex := uint8(1)
+			if delta < math.Pi {
+				colorIndex = 2
+			} else if delta < 2*math.Pi {
+				colorIndex = 3
+			} else if delta < 3*math.Pi {
+				colorIndex = 4
+			}
+
+
+			img.SetColorIndex(int(x*size/10.0+0.5), size+int(y*size/1.0+0.5), colorIndex)
+		}
+		anim.Delay = append(anim.Delay, delay)
+		anim.Image = append(anim.Image, img)
+	}
+
+	gif.EncodeAll(out, &anim)
+}
+
+
+func main() {
+	//defer fmt.Println("Program Exited...")
+	//lissajous(os.Stdout)
+	sint(os.Stdout)
+}
diff --git a/learn/go/exercise/1.7.go b/learn/go/exercise/1.7.go
new file mode 100644
index 0000000..089110f
--- /dev/null
+++ b/learn/go/exercise/1.7.go
@@ -0,0 +1,36 @@
+/*
+ * ------------------------------------------------------------------------
+ *   File Name: 1.7.go
+ *      Author: Zhao Yanbai
+ *              2017-06-11 17:18:40 Sunday CST
+ * Description: none
+ * ------------------------------------------------------------------------
+ */
+package main
+import (
+	"net/http"
+	"os"
+	"io"
+	"log"
+	"strings"
+)
+
+func main() {
+	for _, url := range os.Args[1:] {
+		if !strings.HasPrefix("http://", url) {
+			url = "http://" + url
+		}
+
+		rsp, err := http.Get(url)
+		if err != nil {
+			log.Fatalf("fetch: %s\n", err)
+		}
+
+		if n, err := io.Copy(os.Stdout, rsp.Body); err != nil {
+			log.Fatalf("reading: %s:%s\n", url, err)
+		} else {
+			log.Printf("\nread %d bytes. status code: %v\n", n, rsp.Status)
+		}
+	}
+
+}