maliqq/webtail.go

## webtail.go
package main

import "bytes"
import "io"
import "os"
import "strings"
import "strconv"
import "fmt"
import "flag"
import "net/http"
import "encoding/json"

const (
	TITLE = "Logs"
)

var (
	N = []int{100, 500, 1000, 5000}
)

func urlFor(f string) string {
	return "?file=" + f
}

func urlForTail(f string, n int) string {
	return urlFor(f) + "&n=" + strconv.Itoa(n)
}

func renderListing(files map[string]string) string {
	html := "<html><head><title>" + TITLE + "</title></head><body><ul>"
	for file, _ := range files {
		html += "<li>"

		html += "<a href=\"" + urlFor(file) + "\">"
		html += file
		html += "</a>"

		for _, i := range N {
			html += " (<a href=\"" + urlForTail(file, i) + "#tail\">"
			html += strconv.Itoa(i)
			html += "</a>)"
		}

		html += "</li>"
	}
	html += "</ul></body></html>"
	return html
}

func tail(f string, lines int, w http.ResponseWriter) {
	buffer := bytes.NewBuffer(nil)
	file, _ := os.Open(f)
	io.Copy(buffer, file)
	file.Close()
	bufferString := buffer.String()
	total := strings.Count(bufferString, "\n")
	if total < lines {
		lines = total
	}
	stringArray := strings.Split(bufferString, "\n")
	for i := total - lines; i < total; i++ {
		w.Write([]byte(stringArray[i]))
		w.Write([]byte{0x0a})
	}
}

func main() {
	files := map[string]string{}

	flag.Parse()
	listingFile := flag.Arg(0)
	listing, err := os.Open(listingFile)
	if err != nil {
		fmt.Printf(listingFile)
		panic(err)
	}

	dec := json.NewDecoder(listing)
	dec.Decode(&files)

	fmt.Println(files)

	http.HandleFunc("/logs", func(w http.ResponseWriter, r *http.Request) {
		w.Header().Add("Content-Type", "text/html; charset=UTF-8")

		file := r.FormValue("file")
		if file == "" {
			html := renderListing(files)
			w.Write([]byte(html))
			return
		}
		if path, found := files[file]; found {
			n := r.FormValue("n")
			valid := false
			lines := 0
			if n != "" {
				lines, _ = strconv.Atoi(n)
				for _, i := range N {
					if i == lines {
						valid = true
						break
					}
				}
			}

			w.Write([]byte("<!DOCTYPE html>\n<html><head><title>" + TITLE + "</title></head><body><pre>"))
			if valid {
				fmt.Printf("tailing %s %d\n", path, lines)
				tail(path, lines, w)
			} else {
				fmt.Printf("reading %s\n", path)
				f, _ := os.Open(path)
				io.Copy(w, f)
				f.Close()
			}
			w.Write([]byte("</pre><a name=\"tail\"></a></body></html>"))
			return
		}
		http.Error(w, "Not found", 404)
	})

	http.ListenAndServe("127.0.0.1:10090", nil)
}
	package main

	import "bytes"
	import "io"
	import "os"
	import "strings"
	import "strconv"
	import "fmt"
	import "flag"
	import "net/http"
	import "encoding/json"

	const (
	TITLE = "Logs"
	)

	var (
	N = []int{100, 500, 1000, 5000}
	)

	func urlFor(f string) string {
	return "?file=" + f
	}

	func urlForTail(f string, n int) string {
	return urlFor(f) + "&n=" + strconv.Itoa(n)
	}

	func renderListing(files map[string]string) string {
	html := "<html><head><title>" + TITLE + "</title></head><body><ul>"
	for file, _ := range files {
	html += "<li>"

	html += "<a href=\"" + urlFor(file) + "\">"
	html += file
	html += "</a>"

	for _, i := range N {
	html += " (<a href=\"" + urlForTail(file, i) + "#tail\">"
	html += strconv.Itoa(i)
	html += "</a>)"
	}

	html += "</li>"
	}
	html += "</ul></body></html>"
	return html
	}

	func tail(f string, lines int, w http.ResponseWriter) {
	buffer := bytes.NewBuffer(nil)
	file, _ := os.Open(f)
	io.Copy(buffer, file)
	file.Close()
	bufferString := buffer.String()
	total := strings.Count(bufferString, "\n")
	if total < lines {
	lines = total
	}
	stringArray := strings.Split(bufferString, "\n")
	for i := total - lines; i < total; i++ {
	w.Write([]byte(stringArray[i]))
	w.Write([]byte{0x0a})
	}
	}

	func main() {
	files := map[string]string{}

	flag.Parse()
	listingFile := flag.Arg(0)
	listing, err := os.Open(listingFile)
	if err != nil {
	fmt.Printf(listingFile)
	panic(err)
	}

	dec := json.NewDecoder(listing)
	dec.Decode(&files)

	fmt.Println(files)

	http.HandleFunc("/logs", func(w http.ResponseWriter, r *http.Request) {
	w.Header().Add("Content-Type", "text/html; charset=UTF-8")

	file := r.FormValue("file")
	if file == "" {
	html := renderListing(files)
	w.Write([]byte(html))
	return
	}
	if path, found := files[file]; found {
	n := r.FormValue("n")
	valid := false
	lines := 0
	if n != "" {
	lines, _ = strconv.Atoi(n)
	for _, i := range N {
	if i == lines {
	valid = true
	break
	}
	}
	}

	w.Write([]byte("<!DOCTYPE html>\n<html><head><title>" + TITLE + "</title></head><body><pre>"))
	if valid {
	fmt.Printf("tailing %s %d\n", path, lines)
	tail(path, lines, w)
	} else {
	fmt.Printf("reading %s\n", path)
	f, _ := os.Open(path)
	io.Copy(w, f)
	f.Close()
	}
	w.Write([]byte("</pre><a name=\"tail\"></a></body></html>"))
	return
	}
	http.Error(w, "Not found", 404)
	})

	http.ListenAndServe("127.0.0.1:10090", nil)
	}