Merge pull request #134 from apriendeau/master

#67 creates RunE functions to allow for errors to populate to the top

command.go

@@ -66,14 +66,24 @@ type Command struct {
 	// All functions get the same args, the arguments after the command name
 	// PersistentPreRun: children of this command will inherit and execute
 	PersistentPreRun func(cmd *Command, args []string)
+	// PersistentPreRunE: PersistentPreRun but returns an error
+	PersistentPreRunE func(cmd *Command, args []string) error
 	// PreRun: children of this command will not inherit.
 	PreRun func(cmd *Command, args []string)
+	// PreRunE: PreRun but returns an error
+	PreRunE func(cmd *Command, args []string) error
 	// Run: Typically the actual work function. Most commands will only implement this
 	Run func(cmd *Command, args []string)
+	// RunE: Run but returns an error
+	RunE func(cmd *Command, args []string) error
 	// PostRun: run after the Run command.
 	PostRun func(cmd *Command, args []string)
+	// PostRunE: PostRun but returns an error
+	PostRunE func(cmd *Command, args []string) error
 	// PersistentPostRun: children of this command will inherit and execute after PostRun
 	PersistentPostRun func(cmd *Command, args []string)
+	// PersistentPostRunE: PersistentPostRun but returns an error
+	PersistentPostRunE func(cmd *Command, args []string) error
 	// Commands is the list of commands supported by this program.
 	commands []*Command
 	// Parent Command for this command
@@ -474,22 +484,45 @@ func (c *Command) execute(a []string) (err error) {
 	argWoFlags := c.Flags().Args()
 
 	for p := c; p != nil; p = p.Parent() {
-		if p.PersistentPreRun != nil {
+		if p.PersistentPreRunE != nil {
+			if err := p.PersistentPostRunE(c, argWoFlags); err != nil {
+				return err
+			}
+			break
+		} else if p.PersistentPreRun != nil {
 			p.PersistentPreRun(c, argWoFlags)
 			break
 		}
 	}
-	if c.PreRun != nil {
+	if c.PreRunE != nil {
+		if err := c.PreRunE(c, argWoFlags); err != nil {
+			return err
+		}
+	} else if c.PreRun != nil {
 		c.PreRun(c, argWoFlags)
 	}
 
-	c.Run(c, argWoFlags)
-
-	if c.PostRun != nil {
+	if c.RunE != nil {
+		if err := c.RunE(c, argWoFlags); err != nil {
+			return err
+		}
+	} else {
+		c.Run(c, argWoFlags)
+	}
+	if c.PostRunE != nil {
+		if err := c.PostRunE(c, argWoFlags); err != nil {
+			return err
+		}
+	} else if c.PostRun != nil {
 		c.PostRun(c, argWoFlags)
 	}
 	for p := c; p != nil; p = p.Parent() {
-		if p.PersistentPostRun != nil {
+		if p.PersistentPostRunE != nil {
+			if err := p.PersistentPostRunE(c, argWoFlags); err != nil {
+				return err
+			}
+			break
+		} else if p.PersistentPostRun != nil {
 			p.PersistentPostRun(c, argWoFlags)
 			break
 		}