[Libguestfs] [libguestfs-common PATCH 3/3] add common ("standard") option -w / --wrap
Richard W.M. Jones
rjones at redhat.com
Sat Feb 12 18:18:57 UTC 2022
On Fri, Feb 11, 2022 at 04:32:25PM +0100, Laszlo Ersek wrote:
> Similarly to how users can can force ANSI colorization with "--colors"
> even when stdout / stderr are redirected to a non-tty, allow them to force
> wrapping with "--wrap".
>
> Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1820221
> Signed-off-by: Laszlo Ersek <lersek at redhat.com>
> ---
>
> Notes:
> - This patch will require documentation updates for the following
> guestfs-tools utilities (those that already document "--colours"):
>
> builder/virt-builder-repository.pod
> builder/virt-builder.pod
> customize/virt-customize.pod
> dib/virt-dib.pod
> get-kernel/virt-get-kernel.pod
> resize/virt-resize.pod
> sparsify/virt-sparsify.pod
> sysprep/virt-sysprep.pod
>
> Virt-v2v as well:
>
> docs/virt-v2v.pod
>
> This is evident e.g. from "test-virt-customize-docs.sh" failing in
> guestfs-tools, and "test-v2v-docs.sh" failing in virt-v2v.
>
> If this patch is accepted, I intend to post such guestfs-tools and
> virt-v2v patches that atomically bump the submodule reference and
> update the documentation.
>
> - Some utilities in libguestfs already use the short "-w" option
> (guestfish, guestmount, virt-rescue); however, those utilities do not
> document "--colours", so they already don't make a TTY-based
> distinction, and will not see the new short "-w" option.
Yes, this is awkward.
Do we have to have the short version? I'd really like to not burn
through useful-looking single letter options such as -w -- even if not
currently used in all tools -- for a pretty obscure feature that about
0.0001% of people are going to care about. And as you say guestfish
establishes a clear precedence for this option meaning "writable".
> - Easily testable e.g. with virt-resize:
>
> $ guestfish -N fs:ext4 exit
> $ truncate -s 2G test1.resized.img
> $ virt-resize --expand /dev/sda1 test1.img test1.resized.img
> $ virt-resize -w --expand /dev/sda1 test1.img test1.resized.img
> $ virt-resize --expand /dev/sda1 test1.img test1.resized.img > log1
> $ virt-resize -w --expand /dev/sda1 test1.img test1.resized.img > log2
> $ cat log1
> $ cat log2
>
> mlstdutils/std_utils.mli | 6 ++++--
> mlstdutils/std_utils.ml | 8 ++++++--
> mltools/tools_utils.ml | 3 ++-
> mltools/test-getopt.sh | 2 ++
> 4 files changed, 14 insertions(+), 5 deletions(-)
>
> diff --git a/mlstdutils/std_utils.mli b/mlstdutils/std_utils.mli
> index 534caa80d6a7..87e923e24d29 100644
> --- a/mlstdutils/std_utils.mli
> +++ b/mlstdutils/std_utils.mli
> @@ -376,8 +376,10 @@ val set_trace : unit -> unit
> val trace : unit -> bool
> val set_verbose : unit -> unit
> val verbose : unit -> bool
> -(** Stores the colours ([--colours]), quiet ([--quiet]), trace ([-x]) and
> - verbose ([-v]) flags in global variables. *)
> +val set_wrap : unit -> unit
> +val wrap : unit -> bool
> +(** Stores the colours ([--colours]), quiet ([--quiet]), trace ([-x]), verbose
> + ([-v]) and wrap ([-w]) flags in global variables. *)
>
> val with_open_in : string -> (in_channel -> 'a) -> 'a
> (** [with_open_in filename f] calls function [f] with [filename]
> diff --git a/mlstdutils/std_utils.ml b/mlstdutils/std_utils.ml
> index 58ac058c1b3a..52f44760c490 100644
> --- a/mlstdutils/std_utils.ml
> +++ b/mlstdutils/std_utils.ml
> @@ -580,8 +580,8 @@ let which executable =
> (* Program name. *)
> let prog = Filename.basename Sys.executable_name
>
> -(* Stores the colours (--colours), quiet (--quiet), trace (-x) and
> - * verbose (-v) flags in a global variable.
> +(* Stores the colours (--colours), quiet (--quiet), trace (-x), verbose (-v)
> + * and wrap (-w) flags in a global variable.
> *)
> let colours = ref false
> let set_colours () = colours := true
> @@ -599,6 +599,10 @@ let verbose = ref false
> let set_verbose () = verbose := true
> let verbose () = !verbose
>
> +let wrap = ref false
> +let set_wrap () = wrap := true
> +let wrap () = !wrap
> +
> let with_open_in filename f =
> let chan = open_in filename in
> protect ~f:(fun () -> f chan) ~finally:(fun () -> close_in chan)
> diff --git a/mltools/tools_utils.ml b/mltools/tools_utils.ml
> index 4c5188988e03..eb8da290eec6 100644
> --- a/mltools/tools_utils.ml
> +++ b/mltools/tools_utils.ml
> @@ -126,7 +126,7 @@ let message fs =
> type wrap_break_t = WrapEOS | WrapSpace | WrapNL
>
> let rec wrap ?(chan = stdout) ?(indent = 0) str =
> - if istty chan then
> + if Std_utils.wrap () || istty chan then
> let len = String.length str in
> _wrap chan indent 0 0 len str
> else (
> @@ -388,6 +388,7 @@ let create_standard_options argspec ?anon_fun ?(key_opts = false)
> add_argspec ([ S 'q'; L"quiet" ], Getopt.Unit set_quiet, s_"Don’t print progress messages");
> add_argspec ([ L"color"; L"colors";
> L"colour"; L"colours" ], Getopt.Unit set_colours, s_"Use ANSI colour sequences even if not tty");
> + add_argspec ([ S 'w'; L"wrap" ], Getopt.Unit set_wrap, s_"Wrap log messages even if not tty");
... So what I'd do is drop the -w version (keep the --wrap version of course).
>
> if key_opts then (
> let parse_key_selector arg =
> diff --git a/mltools/test-getopt.sh b/mltools/test-getopt.sh
> index d9919a9a915a..1d7bb7b1dc4f 100755
> --- a/mltools/test-getopt.sh
> +++ b/mltools/test-getopt.sh
> @@ -68,6 +68,7 @@ $t --short-options | grep '^-is'
> $t --short-options | grep '^-t'
> $t --short-options | grep '^-V'
> $t --short-options | grep '^-v'
> +$t --short-options | grep '^-w'
> $t --short-options | grep '^-x'
>
> # --long-options
> @@ -89,6 +90,7 @@ $t --long-options | grep '^--ii'
> $t --long-options | grep '^--is'
> $t --long-options | grep '^--version'
> $t --long-options | grep '^--verbose'
> +$t --long-options | grep '^--wrap'
>
> # -a/--add parameter.
> $t | grep '^adds = \[\]'
> --
> 2.19.1.3.g30247aa5d201
With the appropriate change to drop -w in various places in this patch:
Reviewed-by: Richard W.M. Jones <rjones at redhat.com>
You might as well push the docs & submodule updates in the other tools
without review.
Thanks,
Rich.
--
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
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