[Libguestfs] [PATCH v3 2/2] mllib: Getopt: support hidden options

[Pino Toscano]

Add a dummy description value to mark an option as "hidden", so it will
not be shown in the help text.

Mark few options as hidden:
- common: --short-options, --long-options
- virt-sysprep: --dump-pod, --dump-pod-options
---

Related question: should --debug-gc be considered really internal,
thus marked as such and removed from the documentations?


 mllib/getopt.ml  | 13 ++++++++++---
 mllib/getopt.mli |  4 ++++
 sysprep/main.ml  |  4 ++--
 3 files changed, 16 insertions(+), 5 deletions(-)

diff --git a/mllib/getopt.ml b/mllib/getopt.ml
index 90f4c44..550baa4 100644
--- a/mllib/getopt.ml
+++ b/mllib/getopt.ml
@@ -43,6 +43,8 @@ type t = {
   usage_msg : usage_msg;
 }
 
+let hidden_option_description = ""
+
 external getopt_parse : string array -> (c_keys * spec * doc) array -> ?anon_fun:anon_fun -> usage_msg -> unit = "guestfs_int_mllib_getopt_parse"
 
 let column_wrap = 38
@@ -56,6 +58,11 @@ let show_help h () =
   let prologue = sprintf (f_"%s\nOptions:\n") h.usage_msg in
   Buffer.add_string b prologue;
 
+  let specs = List.filter (
+    fun (_, _, doc) ->
+      doc <> hidden_option_description
+  ) h.specs in
+
   List.iter (
     fun (keys, spec, doc) ->
       let columns = ref 0 in
@@ -88,7 +95,7 @@ let show_help h () =
       );
       Buffer.add_string b doc;
       Buffer.add_char b '\n';
-  ) h.specs;
+  ) specs;
 
   Buffer.output_buffer stdout b;
   exit 0
@@ -158,8 +165,8 @@ let create specs ?anon_fun usage_msg =
     } in
 
   let specs = specs @ [
-    [ "--short-options" ], Unit (display_short_options t), s_"List short options (internal)";
-    [ "--long-options" ], Unit (display_long_options t), s_"List long options (internal)";
+    [ "--short-options" ], Unit (display_short_options t), hidden_option_description;
+    [ "--long-options" ], Unit (display_long_options t), hidden_option_description;
   ] in
 
   (* Decide whether the help option can be added, and which switches use.  *)
diff --git a/mllib/getopt.mli b/mllib/getopt.mli
index 9d9737e..2a8bada 100644
--- a/mllib/getopt.mli
+++ b/mllib/getopt.mli
@@ -47,6 +47,8 @@ type anon_fun = (string -> unit)
 
 type speclist = (keys * spec * doc) list
 
+val hidden_option_description : string
+
 val compare_command_line_args : string -> string -> int
 (** Compare command line arguments for equality, ignoring any leading [-]s. *)
 
@@ -60,6 +62,8 @@ val create : speclist -> ?anon_fun:anon_fun -> usage_msg -> t
     [speclist] is a list of triples [(keys, spec, doc)]: [keys] is a
     list of options, [spec] is the associated action, and [doc] is
     the help text.
+    If [doc] is [Getopt.hidden_option_description], then the option
+    is considered internal, and it is not shown in the help text.
 
     [anon_fun] is an optional function to handle non-option arguments;
     not specifying one means that only options are allowed, and
diff --git a/sysprep/main.ml b/sysprep/main.ml
index 3259d0d..b2df880 100644
--- a/sysprep/main.ml
+++ b/sysprep/main.ml
@@ -121,8 +121,8 @@ let main () =
       [ "-c"; "--connect" ],        Getopt.Set_string (s_"uri", libvirturi),  s_"Set libvirt URI";
       [ "-d"; "--domain" ],        Getopt.String (s_"domain", set_domain),      s_"Set libvirt guest name";
       [ "-n"; "--dryrun"; "--dry-run" ],        Getopt.Set dryrun,            s_"Perform a dry run";
-      [ "--dump-pod" ], Getopt.Unit dump_pod,        s_"Dump POD (internal)";
-      [ "--dump-pod-options" ], Getopt.Unit dump_pod_options, s_"Dump POD for options (internal)";
+      [ "--dump-pod" ], Getopt.Unit dump_pod,        Getopt.hidden_option_description;
+      [ "--dump-pod-options" ], Getopt.Unit dump_pod_options, Getopt.hidden_option_description;
       [ "--enable" ],  Getopt.String (s_"operations", set_enable),      s_"Enable specific operations";
       [ "--format" ],  Getopt.String (s_"format", set_format),      s_"Set format (default: auto)";
       [ "--list-operations" ], Getopt.Unit list_operations, s_"List supported operations";
-- 
2.7.4