Cleanup of less command

Signed-off-by: Ryan O'Leary <ryanoleary@google.com>

cmds/less/main.go

@@ -2,10 +2,10 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// less pages through files
+// less pages through a file
 //
 // Synopsis:
-//     less [OPTIONS] FILES...
+//     less [OPTIONS] FILE
 //
 // Options:
 //     -profile FILE: Save profile in this file
@@ -34,18 +34,21 @@
 //     * N: Jump up to previous search result
 //
 // Author:
-//     Michael Pratt (github.com/prattmic)
+//     Michael Pratt (github.com/prattmic) whom we are forever grateful for
+//     writing https://github.com/prattmic/lesser.
 package main
 
 import (
 	"bytes"
-	"flag"
 	"fmt"
+	"log"
 	"os"
 	"runtime/pprof"
 	"syscall"
 
 	"github.com/nsf/termbox-go"
+	flag "github.com/spf13/pflag"
+	"github.com/u-root/u-root/pkg/less"
 )
 
 var profile = flag.String("profile", "", "Save profile in this file")
@@ -61,11 +64,11 @@ func mmapFile(f *os.File) ([]byte, error) {
 }
 
 func main() {
-	flag.Parse()
 	flag.Usage = func() {
 		fmt.Fprintf(os.Stderr, "Usage of %s: %s filename\n", os.Args[0], os.Args[0])
 		flag.PrintDefaults()
 	}
+	flag.Parse()
 
 	if len(flag.Args()) != 1 {
 		flag.Usage()
@@ -75,35 +78,31 @@ func main() {
 	name := flag.Arg(0)
 	f, err := os.Open(name)
 	if err != nil {
-		fmt.Fprintf(os.Stderr, "Failed to open %s: %v\n", name, err)
-		os.Exit(1)
+		log.Fatalf("failed to open %s: %v", name, err)
 	}
 
 	m, err := mmapFile(f)
 	if err != nil {
-		fmt.Fprintf(os.Stderr, "Failed to mmap file: %v\n", err)
-		os.Exit(1)
+		log.Fatalf("failed to mmap file: %v", err)
 	}
 	defer syscall.Munmap(m)
 
 	err = termbox.Init()
 	if err != nil {
-		fmt.Fprintf(os.Stderr, "Failed to init: %v\n", err)
-		os.Exit(1)
+		log.Fatalf("Failed to init: %v", err)
 	}
 	defer termbox.Close()
 
 	if *profile != "" {
 		p, err := os.Create(*profile)
 		if err != nil {
-			fmt.Fprintf(os.Stderr, "Failed to create profile: %v\n", err)
-			os.Exit(1)
+			log.Fatalf("Failed to create profile: %v", err)
 		}
 		defer p.Close()
 		pprof.StartCPUProfile(p)
 		defer pprof.StopCPUProfile()
 	}
 
-	l := NewLesser(bytes.NewReader(m), *tabStop)
+	l := less.NewLess(bytes.NewReader(m), *tabStop)
 	l.Run()
 }

cmds/less/less.go → pkg/less/less.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-package main
+package less
 
 import (
 	"fmt"
@@ -12,9 +12,9 @@ import (
 	"regexp"
 	"sync"
 
-	"github.com/nsf/termbox-go" // TODO: vendor
-	"github.com/u-root/u-root/cmds/less/lineio"
-	"github.com/u-root/u-root/cmds/less/sortedmap"
+	"github.com/nsf/termbox-go"
+	"github.com/u-root/u-root/pkg/lineio"
+	"github.com/u-root/u-root/pkg/sortedmap"
 )
 
 type size struct {
@@ -43,7 +43,7 @@ const (
 	ModeSearchEntry
 )
 
-type Lesser struct {
+type Less struct {
 	// src is the source file being displayed.
 	src lineio.LineReader
 
@@ -72,13 +72,13 @@ type Lesser struct {
 
 	// searchResults are the results for the current search.
 	// They should be highlighted.
-	searchResults searchResults
+	searchResults *searchResults
 }
 
 // lastLine returns the last line on the display.  It may be beyond the end
 // of the file, if the file is short enough.
 // mu must be held on call.
-func (l *Lesser) lastLine() int64 {
+func (l *Less) lastLine() int64 {
 	return l.line + int64(l.size.y) - 1
 }
 
@@ -107,7 +107,7 @@ const (
 // scrollLine tries to scroll the display to the given line,
 // but will not scroll beyond the first or last lines in the file.
 // l.mu must be held when calling scrollLine.
-func (l *Lesser) scrollLine(dest int64) {
+func (l *Less) scrollLine(dest int64) {
 	var delta int64
 	if dest > l.line {
 		delta = 1
@@ -122,7 +122,7 @@ func (l *Lesser) scrollLine(dest int64) {
 
 // scroll moves the display based on the passed scroll action, without
 // going past the beginning or end of the file.
-func (l *Lesser) scroll(s Scroll) {
+func (l *Less) scroll(s Scroll) {
 	l.mu.Lock()
 	defer l.mu.Unlock()
 
@@ -150,7 +150,7 @@ func (l *Lesser) scroll(s Scroll) {
 	l.scrollLine(dest)
 }
 
-func (l *Lesser) handleEvent(e termbox.Event) {
+func (l *Less) handleEvent(e termbox.Event) {
 	l.mu.Lock()
 	mode := l.mode
 	l.mu.Unlock()
@@ -238,7 +238,7 @@ func (l *Lesser) handleEvent(e termbox.Event) {
 	}
 }
 
-func (l *Lesser) listenEvents() {
+func (l *Less) listenEvents() {
 	for {
 		e := termbox.PollEvent()
 		l.handleEvent(e)
@@ -278,8 +278,8 @@ type searchResults struct {
 	results []searchResult
 }
 
-func NewSearchResults() searchResults {
-	return searchResults{
+func NewSearchResults() *searchResults {
+	return &searchResults{
 		lines: sortedmap.NewMap(),
 	}
 }
@@ -337,7 +337,7 @@ func (s *searchResults) Prev(line int64) (searchResult, bool) {
 	return s.results[i], true
 }
 
-func (l *Lesser) search(s string) searchResults {
+func (l *Less) search(s string) *searchResults {
 	reg, err := regexp.Compile(s)
 	if err != nil {
 		// TODO(prattmic): display a better error
@@ -407,7 +407,7 @@ func (l *Lesser) search(s string) searchResults {
 
 // statusBar renders the status bar.
 // mu must be held on call.
-func (l *Lesser) statusBar() {
+func (l *Less) statusBar() {
 	// The statusbar is just below the display.
 
 	// Clear the statusbar
@@ -435,7 +435,7 @@ func alignUp(n, divisor int) int {
 	return n + (divisor - (n % divisor))
 }
 
-func (l *Lesser) refreshScreen() error {
+func (l *Less) refreshScreen() error {
 	l.mu.Lock()
 	defer l.mu.Unlock()
 
@@ -491,7 +491,7 @@ func (l *Lesser) refreshScreen() error {
 	return nil
 }
 
-func (l *Lesser) Run() {
+func (l *Less) Run() {
 	// Start populating the LineReader cache, to speed things up later.
 	go l.src.Populate()
 
@@ -519,16 +519,17 @@ func (l *Lesser) Run() {
 	}
 }
 
-func NewLesser(r io.ReaderAt, ts int) Lesser {
+func NewLess(r io.ReaderAt, ts int) Less {
 	x, y := termbox.Size()
 
-	return Lesser{
+	return Less{
 		src:     lineio.NewLineReader(r),
 		tabStop: ts,
 		// Save one line for statusbar.
-		size:   size{x: x, y: y - 1},
-		line:   1,
-		events: make(chan Event, 1),
-		mode:   ModeNormal,
+		size:          size{x: x, y: y - 1},
+		line:          1,
+		events:        make(chan Event, 1),
+		mode:          ModeNormal,
+		searchResults: NewSearchResults(),
 	}
 }

cmds/less/lineio/lineio.go → pkg/lineio/lineio.go

@@ -8,7 +8,7 @@ import (
 	"io"
 	"regexp"
 
-	"github.com/u-root/u-root/cmds/less/sortedmap"
+	"github.com/u-root/u-root/pkg/sortedmap"
 )
 
 type LineReader struct {
@@ -57,7 +57,7 @@ func (l *LineReader) scanForLine(line, curLine, curOffset int64) (offset int64,
 				}
 			}
 
-			curLine += 1
+			curLine++
 
 			l.offsetCache.Insert(curLine, offset)
 

cmds/less/sortedmap/sortedmap.go → pkg/sortedmap/sortedmap.go

@@ -10,7 +10,7 @@ import (
 	"sync"
 )
 
-var ErrNoSuchKey = errors.New("No such key exists.")
+var ErrNoSuchKey = errors.New("no such key exists")
 
 // SearchInt64s implements sort.SearchInts for int64.
 func SearchInt64s(a []int64, x int64) int {

cmds/less/sortedmap/sortedmap_test.go → pkg/sortedmap/sortedmap_test.go

@@ -79,30 +79,30 @@ func TestDelete(t *testing.T) {
 		},
 	}
 
-	for _, c := range cases {
-		for _, k := range c.del {
-			c.before.Delete(k)
+	for i := range cases {
+		for _, k := range cases[i].del {
+			cases[i].before.Delete(k)
 		}
 
 		// All expected entries exist
-		for k, e := range c.after.m {
-			v, ok := c.before.m[k]
+		for k, e := range cases[i].after.m {
+			v, ok := cases[i].before.m[k]
 			if !ok {
-				t.Errorf("%d not found in %v", k, c.before.m)
+				t.Errorf("%d not found in %v", k, cases[i].before.m)
 			}
 			if v != e {
-				t.Errorf("got %d want %d in %v", v, e, c.before.m)
+				t.Errorf("got %d want %d in %v", v, e, cases[i].before.m)
 			}
 		}
 
-		if len(c.before.k) != len(c.after.k) {
-			t.Errorf("Bad length, got %d, expected %d. %v vs %v", len(c.before.k), len(c.after.k), c.before.k, c.after.k)
+		if len(cases[i].before.k) != len(cases[i].after.k) {
+			t.Errorf("Bad length, got %d, expected %d. %v vs %v", len(cases[i].before.k), len(cases[i].after.k), cases[i].before.k, cases[i].after.k)
 		}
 
 		// Key slice is correct
-		for i, e := range c.after.k {
-			if c.before.k[i] != e {
-				t.Errorf("Got %v, expected %v", c.before.k, c.after.k)
+		for i, e := range cases[i].after.k {
+			if cases[i].before.k[i] != e {
+				t.Errorf("Got %v, expected %v", cases[i].before.k, cases[i].after.k)
 				break
 			}
 		}