Implement the "recursive" mode: automatically add any dependencies needed for the new service

2 files changed, 60 insertions, 61 deletions

diff --git a/main.go b/main.go
index 105c2a2..3d7c662 100644
--- a/main.go
+++ b/main.go
@@ -13,7 +13,7 @@ var opts struct {
 	List bool `long:"list" description:"List services"`
 	Add  bool `long:"add" description:"Add services"`
 	Del  bool `long:"del" description:"Delete services"`
-	Recurse bool `long:"recursive" short:"t" description:"Recursively process dependencies"`
+	Recursive bool `long:"recursive" short:"t" description:"Recursively process dependencies"`
 	Defaults bool `long:"defaults" short:"D" description:"Restore defaults"`
 	LF func(string) `short:"l" long:"level" value-name:"L[L...]" description:"apply to these runlevels"`
 	Level []string 
@@ -144,10 +144,8 @@ type NameChecker func () bool
 func LoadListing(initdir *InitDir, sel NameSelector) (*Listing, error) {
 	var lst Listing
 	next := initdir.Iterator(sel)
-	srv := next()
-	for srv != nil {
+	for srv := next(); srv != nil; srv = next() {
 		lst.rows = append(lst.rows, ListingRow{name: srv.BaseName()})
-		srv = next()
         }
 	return &lst, nil
 }
@@ -183,30 +181,25 @@ func List(args *ArgList) {
 
 	// Iterate over selected runlevels
 	next := rs.Iterator()
-	r := next()
-	for r.IsValid() {
-		// Scan the rc<r>,d directory.
+	for r := next(); r.IsValid(); r = next() {
+		// Scan the rc<r>.d directory.
 		rcd, err := LoadRCDir(r, initdir)
 		if err != nil {
 			continue
 		}
 		// Iterate over all SystemV services in its start sequence.
 		nextserv := rcd.Start.SysVServiceIterator()
-		srv := nextserv()
-		for srv != nil {
+		for srv := nextserv(); srv != nil; srv = nextserv() {
 			// Mark each such service as enabled for the runlevel.
 			lst.Set(srv.BaseName(), r)
-			srv = nextserv()
 		}
-		r = next()
 	}
 
 	// Print the resulting listing.
 	for _, row := range lst.rows {
 		fmt.Printf("%-16s", row.name)
 		next = rs.Iterator()
-		r = next()
-		for r.IsValid() {
+		for r := next(); r.IsValid(); r = next() {
 			var s string
 			if (row.on[r.Index()]) {
 				s = "on"
@@ -214,7 +207,6 @@ func List(args *ArgList) {
 				s = "off"
 			}
 			fmt.Printf("   %s:%-3s", r.Letter(), s)
-			r = next()
 		}
 		fmt.Println()
 	}
@@ -243,12 +235,10 @@ func Del(args *ArgList) {
 
 	// Repeat for each service named in the command line:
 	nextservice := initdir.Iterator(args.GetNameSelector())
-	wanted := nextservice()
-	for wanted != nil {
+	for wanted := nextservice(); wanted != nil; wanted = nextservice() {
 		// iterate over all requested runlevels
 		nextlevel := rs.Iterator()
-		r := nextlevel()
-		for r.IsValid() {
+		for r := nextlevel(); r.IsValid(); r = nextlevel() {
 			// Scan the rc<r>,d directory.
 			rcd, err := LoadRCDir(r, initdir)
 			if err != nil {
@@ -258,31 +248,23 @@ func Del(args *ArgList) {
 			// Iterate over all SystemV services in its start
 			// sequence:
 			nextsysv := rcd.Start.SysVServiceIterator()
-			srv := nextsysv()
-			for srv != nil {
+			for srv := nextsysv(); srv != nil; srv = nextsysv() {
 				// If the service basename matches, add its
 				// file name to the list.
 				if srv.BaseName() == wanted.BaseName() {
 					oplist.Append(NewUnlink(srv.FileName()))
 				}
-				srv = nextsysv()
 			}
 
 			// Do the same for all services in the stop
 			// sequence.
 			nextsysv = rcd.Stop.SysVServiceIterator()
-			srv = nextsysv()
-			for srv != nil {
+			for srv := nextsysv(); srv != nil; srv = nextsysv() {
 				if srv.BaseName() == wanted.BaseName() {
 					oplist.Append(NewUnlink(srv.FileName()))
 				}
-				srv = nextsysv()
 			}
-			
-			r = nextlevel()
 		}
-
-		wanted = nextservice()
 	}
 	// Check and report any unconsumed arguments
 	args.Report()		
@@ -368,10 +350,6 @@ func (d *InitDir) AddDependencies(srvin []Service) (srvout []Service) {
 }
 
 func Add(args *ArgList) {
-	if args.Len() == 0 {
-		Logger.Fatal(`not enough arguments`)
-	}
-
 	// Load the content of the init.d directory.
 	initdir, err := LoadInitDir(InitDirectory)
 	if err != nil {
@@ -384,18 +362,48 @@ func Add(args *ArgList) {
 	var services []Service // Services to be added
 	var rsStart Runlevels  // Start levels
 	var rsStop Runlevels   // Stop levels
+	var rcdir [NumLevels]*RCDir  // All needed rcN.d directories
 
 	// Collect services to be added
-	nextservice := initdir.Iterator(args.GetNameSelector())
-	srv := nextservice()
-	for srv != nil {
-		services = append(services, srv)
-		srv = nextservice()
+	if args.Len() > 0 {
+		nextservice := initdir.Iterator(args.GetNameSelector())
+		for srv := nextservice(); srv != nil; srv = nextservice() {
+			services = append(services, srv)
+	        }
+		// If any unused arguments remain, report them and exit.
+	        args.Report()
+	} else if opts.Defaults {
+		s := make(map[string]bool)
+		nextlevel := GetRunlevels().Iterator()
+		for r := nextlevel(); r.IsValid(); r = nextlevel() {
+			rcd, err := LoadRCDir(r, initdir)
+			if err != nil {
+				Logger.Fatal("failed to load rc directory: " + err.Error())
+		        }
+		        rcdir[r.Index()] = rcd
+
+			nextserv := rcd.Start.SysVServiceIterator()
+			for srv := nextserv(); srv != nil; srv = nextserv() {
+				if ! s[srv.BaseName()] {
+					services = append(services, srv)
+					s[srv.BaseName()] = true
+				}
+			}
+
+			nextserv = rcd.Stop.SysVServiceIterator()
+			for srv := nextserv(); srv != nil; srv = nextserv() {
+				if ! s[srv.BaseName()] {
+					services = append(services, srv)
+					s[srv.BaseName()] = true
+				}
+			}
+		}
+	} else {
+		Logger.Fatal(`not enough arguments`)
 	}
-	// If any unused arguments remain, report them and exit.
-	args.Report()
 
-	if opts.Recurse {
+	
+	if opts.Recursive {
 		services = initdir.AddDependencies(services)
 	}
 
@@ -410,20 +418,19 @@ func Add(args *ArgList) {
 	rsStop.And(rsmask)
 	
 	// Load rc directories
-	var rcdir [NumLevels]*RCDir  // All needed rcN.d directories
 	var rs Runlevels             // A union of start and stop runlevels
 	rs.Or(rsStart)
 	rs.Or(rsStop)
 	// Iterate over all runlevels and load the corresponding rc directories
 	nextlevel := rs.Iterator()
-	r := nextlevel()
-	for r.IsValid() {
-		rcd, err := LoadRCDir(r, initdir)
-		if err != nil {
-			Logger.Fatal("failed to load startup directory: " + err.Error())
+	for r := nextlevel(); r.IsValid(); r = nextlevel() {
+		if rcdir[r.Index()] == nil {
+			rcd, err := LoadRCDir(r, initdir)
+			if err != nil {
+				Logger.Fatal("failed to load rc directory: " + err.Error())
+		        }
+		        rcdir[r.Index()] = rcd
 		}
-		rcdir[r.Index()] = rcd
-		r = nextlevel()
 	}
 
 	// Array of symlinks to be created
@@ -436,21 +443,17 @@ func Add(args *ArgList) {
 		}
 		
 		nextlevel := rsStart.Iterator()
-		r := nextlevel()
-		for r.IsValid() {
+		for r := nextlevel(); r.IsValid(); r = nextlevel() {
 			if s := rcdir[r.Index()].Start.Inc(srv); s != nil {
 				oplist.Concat(s)
 			}
-			r = nextlevel()
                 }
 		
 		nextlevel = rsStop.Iterator()
-		r = nextlevel()
-		for r.IsValid() {
+		for r := nextlevel(); r.IsValid(); r = nextlevel() {
 			if s := rcdir[r.Index()].Stop.Inc(srv); s != nil {
 				oplist.Concat(s)
 			}
-			r = nextlevel()
 		}
 	}
 
@@ -622,8 +625,7 @@ func (rseq *RCSeq) Inc(newsrv Service) *FileOpList {
 	
 	prio := NewPriority(rseq.Isstart)
 	next := rseq.StartTraversal(srvno)
-	srv := next()
-	for srv != nil {
+	for srv := next(); srv != nil; srv = next() {
 //		fmt.Printf("Traversing: %s\n", srv.BaseName())
 		if ok, diag := srv.Enabled(); !ok {
 			Logger.Printf("%s: %s depends on %s, which is not enabled\n",
@@ -634,16 +636,13 @@ func (rseq *RCSeq) Inc(newsrv Service) *FileOpList {
 			return nil
 		}
 		prio.Update(srv.Priority())
-		srv = next()
 	}
 	prio.Incr()
 	// Traverse services that have the same dependencies	
 	next = rseq.TraverseEquidependentServices(srvno)
-	srv = next()
-	for srv != nil {
+	for srv := next(); srv != nil; srv = next() {
 //		fmt.Printf("Traversing: %s %d\n", srv.BaseName(), srv.Priority())
 		prio.Update(srv.Priority())
-		srv = next()
 	}
 	rseq.Service[srvno].SetPriority(prio.Value())
 
diff --git a/rcd.go b/rcd.go
index ad8c5fd..1813226 100644
--- a/rcd.go
+++ b/rcd.go
@@ -112,7 +112,7 @@ func (seq *RCSeq) BuildDependencies() {
 
 // Return an interator over all SystemV services in SEQ.
 func (seq *RCSeq) SysVServiceIterator() ServiceIterator {
-	i := 0
+	i := 1 // Skip the initial $undefined
 	return func () Service {
 		for i < len(seq.Service) {
 			srv := seq.Service[i]