Merge pull request #3 from akhilpai/master
Commander output and error specification support for subcommands.
diff --git a/subcommands.go b/subcommands.go
index 986f712..d739a57 100644
--- a/subcommands.go
+++ b/subcommands.go
@@ -54,6 +54,9 @@
topFlags *flag.FlagSet // top-level flags
important []string // important top-level flags
name string // normally path.Base(os.Args[0])
+
+ Output io.Writer // Output specifies where the commander should write its output (default: os.Stdout).
+ Error io.Writer // Error specifies where the commander should write its error (default: os.Stderr).
}
// A commandGroup represents a set of commands about a common topic.
@@ -79,8 +82,10 @@
cdr := &Commander{
topFlags: topLevelFlags,
name: name,
+ Output: os.Stdout,
+ Error: os.Stderr,
}
- topLevelFlags.Usage = func() { cdr.explain(os.Stderr) }
+ topLevelFlags.Usage = func() { cdr.explain(cdr.Error) }
return cdr
}
@@ -129,7 +134,7 @@
continue
}
f := flag.NewFlagSet(name, flag.ContinueOnError)
- f.Usage = func() { explain(os.Stderr, cmd) }
+ f.Usage = func() { explain(cdr.Error, cmd) }
cmd.SetFlags(f)
if f.Parse(cdr.topFlags.Args()[1:]) != nil {
return ExitUsageError
@@ -225,7 +230,7 @@
func (h *helper) Execute(_ context.Context, f *flag.FlagSet, args ...interface{}) ExitStatus {
switch f.NArg() {
case 0:
- (*Commander)(h).explain(os.Stdout)
+ (*Commander)(h).explain(h.Output)
return ExitSuccess
case 1:
@@ -234,11 +239,11 @@
if f.Arg(0) != cmd.Name() {
continue
}
- explain(os.Stdout, cmd)
+ explain(h.Output, cmd)
return ExitSuccess
}
}
- fmt.Fprintf(os.Stderr, "Subcommand %s not understood\n", f.Arg(0))
+ fmt.Fprintf(h.Error, "Subcommand %s not understood\n", f.Arg(0))
}
f.Usage()
@@ -272,7 +277,7 @@
if f.NArg() == 0 {
if flg.topFlags == nil {
- fmt.Println("No top-level flags are defined.")
+ fmt.Fprintln(flg.Output, "No top-level flags are defined.")
} else {
flg.topFlags.PrintDefaults()
}
@@ -285,13 +290,13 @@
continue
}
subflags := flag.NewFlagSet(cmd.Name(), flag.PanicOnError)
- subflags.SetOutput(os.Stdout)
+ subflags.SetOutput(flg.Output)
cmd.SetFlags(subflags)
subflags.PrintDefaults()
return ExitSuccess
}
}
- fmt.Fprintf(os.Stderr, "Subcommand %s not understood\n", f.Arg(0))
+ fmt.Fprintf(flg.Error, "Subcommand %s not understood\n", f.Arg(0))
return ExitFailure
}
@@ -319,7 +324,7 @@
for _, group := range l.commands {
for _, cmd := range group.commands {
- fmt.Printf("%s\n", cmd.Name())
+ fmt.Fprintf(l.Output, "%s\n", cmd.Name())
}
}
return ExitSuccess
