Add support for path arguments to filter output

README.md

@@ -57,30 +57,24 @@ You can simply start duf without any command-line arguments:
 
     duf
 
+If you supply arguments, duf will only list specific devices & mount points:
+
+    duf /home /some/file
+
 If you want to list everything (including pseudo, duplicate, inaccessible file systems):
 
     duf --all
 
-You can show only individual tables:
+You can show and hide specific tables:
 
     duf --only local,network,fuse,special,loops,binds
-
-You can also show only specific filesystems:
-
-    duf --only-fs tmpfs,vfat
-
-You can hide individual tables:
-
     duf --hide local,network,fuse,special,loops,binds
 
-You can also hide specific filesystems:
+You can also show and hide specific filesystems:
 
+    duf --only-fs tmpfs,vfat
     duf --hide-fs tmpfs,vfat
 
-List inode information instead of block usage:
-
-    duf --inodes
-
 Sort the output:
 
     duf --sort size
@@ -95,6 +89,10 @@ Show or hide specific columns:
 Valid keys are: `mountpoint`, `size`, `used`, `avail`, `usage`, `inodes`,
 `inodes_used`, `inodes_avail`, `inodes_usage`, `type`, `filesystem`.
 
+List inode information instead of block usage:
+
+    duf --inodes
+
 If duf doesn't detect your terminal's colors correctly, you can set a theme:
 
     duf --theme light

filesystems.go

@@ -1,5 +1,50 @@
 package main
 
+import (
+	"os"
+	"path/filepath"
+	"strings"
+)
+
+func findMounts(mounts []Mount, path string) ([]Mount, error) {
+	var err error
+	path, err = filepath.Abs(path)
+	if err != nil {
+		return nil, err
+	}
+
+	_, err = os.Stat(path)
+	if err != nil {
+		return nil, err
+	}
+
+	var m []Mount
+	for _, v := range mounts {
+		if path == v.Device {
+			return []Mount{v}, nil
+		}
+
+		if strings.HasPrefix(path, v.Mountpoint) {
+			var nm []Mount
+
+			// keep all entries that are as close or closer to the target
+			for _, mv := range m {
+				if len(mv.Mountpoint) >= len(v.Mountpoint) {
+					nm = append(nm, mv)
+				}
+			}
+			m = nm
+
+			// add entry only if we didn't already find something closer
+			if len(nm) == 0 || len(v.Mountpoint) >= len(nm[0].Mountpoint) {
+				m = append(m, v)
+			}
+		}
+	}
+
+	return m, nil
+}
+
 func deviceType(m Mount) string {
 	if isNetworkFs(m) {
 		return networkDevice

main.go

@@ -129,8 +129,24 @@ func main() {
 		os.Exit(0)
 	}
 
+	// read mount table
+	m, warnings, err := mounts()
+	if err != nil {
+		fmt.Fprintln(os.Stderr, err)
+		os.Exit(1)
+	}
+
+	// print JSON
+	if *jsonOutput {
+		err := renderJSON(m)
+		if err != nil {
+			fmt.Fprintln(os.Stderr, err)
+		}
+
+		return
+	}
+
 	// validate theme
-	var err error
 	theme, err = loadTheme(*themeOpt)
 	if err != nil {
 		fmt.Fprintln(os.Stderr, err)
@@ -174,23 +190,21 @@ func main() {
 		OnlyFilesystems:   parseCommaSeparatedValues(*onlyFs),
 	}
 
-	// detect terminal width
-	isTerminal := terminal.IsTerminal(int(os.Stdout.Fd()))
-	if isTerminal && *width == 0 {
-		w, _, err := terminal.GetSize(int(os.Stdout.Fd()))
-		if err == nil {
-			*width = uint(w)
+	// validate arguments
+	if len(flag.Args()) > 0 {
+		var mounts []Mount
+
+		for _, v := range flag.Args() {
+			fm, err := findMounts(m, v)
+			if err != nil {
+				fmt.Println(err)
+				os.Exit(1)
+			}
+
+			mounts = append(mounts, fm...)
 		}
-	}
-	if *width == 0 {
-		*width = 80
-	}
 
-	// read mount table
-	m, warnings, err := mounts()
-	if err != nil {
-		fmt.Fprintln(os.Stderr, err)
-		os.Exit(1)
+		m = mounts
 	}
 
 	// print out warnings
@@ -200,14 +214,16 @@ func main() {
 		}
 	}
 
-	// print JSON
-	if *jsonOutput {
-		err := renderJSON(m)
-		if err != nil {
-			fmt.Fprintln(os.Stderr, err)
+	// detect terminal width
+	isTerminal := terminal.IsTerminal(int(os.Stdout.Fd()))
+	if isTerminal && *width == 0 {
+		w, _, err := terminal.GetSize(int(os.Stdout.Fd()))
+		if err == nil {
+			*width = uint(w)
 		}
-
-		return
+	}
+	if *width == 0 {
+		*width = 80
 	}
 
 	// print tables