get device numbers for block and char device files

CHANGELOG.md

@@ -1,3 +1,8 @@
+### 2018-06-16
+- Fix the calculation of kB, MB, GB, etc. which have graduations of 1024, not 1000.
+- Add more precision to the file sizes.
+- For block and char devices, show major and minor device numbers, instead of simply displaying 0 for file size.
+
 ### 2018-01-22
 
 - Fix permission string generation to produce the same output as `ls -l`.

ls-go.go

@@ -201,7 +201,11 @@ func listFiles(parentDir string, items *[]os.FileInfo, forceDotfiles bool) {
 		}
 
 		if *args.bytes {
-			displayItem.display += sizeString(fileInfo.Size())
+			if fileInfo.Mode()&os.ModeDevice != 0 {
+				displayItem.display += deviceNumbers(path.Join(absPath, fileInfo.Name()))
+			} else {
+				displayItem.display += sizeString(fileInfo.Size())
+			}
 		}
 
 		if *args.mdate {

ls-unix.go

@@ -6,7 +6,12 @@ import (
 	"fmt"
 	"os"
 	"os/user"
+	"strconv"
+	"strings"
 	"syscall"
+
+	"github.com/willf/pad"
+	"golang.org/x/sys/unix"
 )
 
 func getOwnerAndGroup(fileInfo *os.FileInfo) (string, string) {
@@ -19,3 +24,12 @@ func getOwnerAndGroup(fileInfo *os.FileInfo) (string, string) {
 	check(err)
 	return owner.Username, group.Name
 }
+
+func deviceNumbers(absPath string) string {
+	stat := syscall.Stat_t{}
+	err := syscall.Stat(absPath, &stat)
+	check(err)
+	major := strconv.FormatInt(int64(unix.Major(uint64(stat.Rdev))), 10)
+	minor := strconv.FormatInt(int64(unix.Minor(uint64(stat.Rdev))), 10)
+	return pad.Left(strings.Join([]string{major, minor}, ","), 7, " ") + " " + Reset
+}

ls-windows.go

@@ -4,8 +4,13 @@ package main
 
 import (
 	"os"
+	"strconv"
+	"strings"
 	"syscall"
 	"unsafe"
+
+	"github.com/willf/pad"
+	"golang.org/x/sys/windows"
 )
 
 var (
@@ -49,3 +54,12 @@ func getOwnerAndGroup(fileInfo *os.FileInfo) (string, string) {
 	}
 	return uid, gid
 }
+
+func deviceNumbers(absPath string) string {
+	stat := syscall.Stat_t{}
+	err := syscall.Stat(absPath, &stat)
+	check(err)
+	major := strconv.FormatInt(int64(windows.Major(uint64(stat.Rdev))), 10)
+	minor := strconv.FormatInt(int64(windows.Minor(uint64(stat.Rdev))), 10)
+	return pad.Left(strings.Join([]string{major, minor}, ","), 7, " ") + " " + Reset
+}