Re: [PATCH 2/3] Option to set title of submenus

Re: [PATCH 2/3] Option to set title of submenus

[Avnish Chouhan]

> Message: 2
> Date: Mon, 26 May 2025 20:18:26 +0200
> From: Jiří Wolker <projects@jwo.cz>
> To: grub-devel@gnu.org
> Cc: Jiří 'bindiff' Wolker <projects@jwo.cz>
> Subject: [PATCH 2/3] Option to set title of submenus
> Message-ID: <87cybvdyml.fsf@gnat.mail-host-address-is-not-set>
> Content-Type: text/plain; charset=utf-8
> 
> ---
>  grub-core/commands/menuentry.c | 50 ++++++++++++++++++++++++++++++++++
>  1 file changed, 50 insertions(+)
> 
> diff --git a/grub-core/commands/menuentry.c 
> b/grub-core/commands/menuentry.c
> index 720e6d8ea..c40b27d8b 100644
> --- a/grub-core/commands/menuentry.c
> +++ b/grub-core/commands/menuentry.c
> @@ -43,6 +43,9 @@ static const struct grub_arg_option options[] =
>         anyone can boot it.  */
>      {"unrestricted", 0, 0, N_("This entry can be booted by any 
> user."),
>       0, ARG_TYPE_NONE},
> +    {"menutitle", 0, 0,
> +     N_("Use STRING as menu title. When omitted, use the entry 
> label."),
> +     N_("TITLE"), ARG_TYPE_STRING},
>      {0, 0, 0, 0, 0, 0}
>    };
> 
> @@ -252,12 +255,46 @@ setparams_prefix (int argc, char **args)
>    return result;
>  }
> 
> +static char *
> +menutitle_prefix (char *old_prefix, const char *title)
> +{
> +  const char *t;
> +  char *p;
> +  char *result;
> +  grub_size_t len = 22;
> +  grub_size_t old_len = grub_strlen (old_prefix);
> +
> +  /* Count resulting string length. */
> +  for (t = title; *t; t++)
> +    {
> +      len += (*t++ == '\'' ? 4 : 1);
> +    }
> +
> +  result = grub_malloc (old_len + len + 2);
> +  if (! result)
> +    return 0;
> +
> +  p = result;
> +  grub_strcpy (p, old_prefix);
> +  p = result + old_len;
> +  grub_strcpy (p, "set grub_menu_title='");
> +  p += 21;
> +
> +  p = grub_strchrsub (p, title, '\'', "'\\''");
> +  *p++ = '\'';
> +  *p++ = '\n';
> +  *p = '\0';
> +
> +  return result;
> +}
> +
>  static grub_err_t
>  grub_cmd_menuentry (grub_extcmd_context_t ctxt, int argc, char **args)
>  {
>    char ch;
>    char *src;
>    char *prefix;
> +  char *old_prefix;
>    unsigned len;
>    grub_err_t r;
>    const char *users;
> @@ -299,6 +336,19 @@ grub_cmd_menuentry (grub_extcmd_context_t ctxt,
> int argc, char **args)
>    if (! prefix)
>      return grub_errno;
> 
> +  /* Prepend the menu title line. */
> +  if (ctxt->state[6].arg)
> +    {
> +      old_prefix = prefix;
> +      prefix = menutitle_prefix (old_prefix,
> +				 (ctxt->state[6].arg
> +				  && grub_strlen(ctxt->state[6].arg) > 0)
> +				 ? ctxt->state[6].arg : args[0]);

Hi Jiří,

Something like this below might be better here!

prefix = menutitle_prefix (old_prefix, (ctxt->state[6].arg
                            && grub_strlen(ctxt->state[6].arg) > 0)
                            ? ctxt->state[6].arg : args[0]);

> +      if (! prefix)
> +	return grub_errno;

Indention seems off!

> +      grub_free(old_prefix);

grub_free (old_prefix);

Thank you,

Regards,
Avnish Chouhan

> +    }
> +
>    r = grub_normal_add_menu_entry (argc - 1, (const char **) args,
>  				  ctxt->state[0].args, ctxt->state[4].arg,
>  				  users,
> --
> 2.45.3
> 
> 
> 
> 
> ------------------------------

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Re: [PATCH 2/3] Option to set title of submenus

[Jiří 'bindiff' Wolker via Grub-devel]

> Hi Jiří,
> 
> Something like this below might be better here!
> 
> [… source code fixes …]

Hi Avnish,

Thanks for you fix suggestions.

I did not write anything in the GNU coding style for a long time. Also,
using my default mail client was absolutely wrong (and lazy) decision –
it did corrupt whitespace in the patches.

I'm sorry and I'll send reviewed patches in a few minutes.

Thanks.
bindiff

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[PATCH 0/3] Allow script-configurable GRUB menu title

[Jiří 'bindiff' Wolker via Grub-devel]

This patches allow setting custom title of menus in the GRUB menu-based
interface.

This introduces new environment variable ‘grub_menu_title’ which can be
set by the script to override the title shown in the text-based GRUB
menu. This replaces the “GNU GRUB  <version>” message, which was set to
this fixed value in the source code. Now, the module ‘normal’ uses only
this variable as the title text. As part of the module initialisation,
the value which was previously hard-coded, is set to this variable.

The ‘grub_menu_title’ variable is automatically exported to provide the
same title also in the submenus.

I have chosen the ‘grub_’ prefix to reduce possibility of clashes with
user-defined variables in existing GRUB scripts.

Any scripts using this variable to override the title will fail safely,
when a version of GNU GRUB before these changes is used to run them. The
GRUB will display the hard-coded title, not causing the script to fail
and only degrading the user-experience a bit.

Additionally, a new option ‘--menutitle’ is accepted by the ‘menuentry’
and ‘submenu’ commands. This option allows overriding the title for a
submenu. This leverages existing ‘prefix’ mechanism which was previously
used only to prepend the ‘setparams’ line to the source code of menu
entries and submenus.

If newly created scripts require to be compatible even with previous
versions of GRUB, the script authors can use one of these approaches:

* Use ‘set grub_menu_title="Some title"’ variable assignment
   explicitly. This will cause no compatibility issues.
* Use the ‘--menutitle’ option of the ‘submenu’ command _after_ the menu
   entry title. This will cause the option to be silently ignored by
   versions of GRUB not supporting this option, However, the title will
   be passed as a part of ‘setparams’ line of the menu entry or submenu.

I also decided to rename the ‘msg_formatted’ variable in
‘grub_normal_init_page()’ function to ‘msg_title’, which is a more
descriptive title.

My motivation for these changes was to make it easier to navigate in
more complex nested menus, such as on live disks containing a
multiplicity of operating systems.

Jiří Wolker (3):
   Customization of GRUB menu title
   Option to set title of submenus
   Documentation for the --menutitle option

  docs/grub.texi                 | 13 +++++++--
  grub-core/commands/menuentry.c | 50 ++++++++++++++++++++++++++++++++++
  grub-core/normal/main.c        | 19 +++++++++----
  3 files changed, 74 insertions(+), 8 deletions(-)

-- 
2.45.3


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[PATCH 2/3] Option to set title of submenus

[Jiří Wolker via Grub-devel]

---
 grub-core/commands/menuentry.c | 50 ++++++++++++++++++++++++++++++++++
 1 file changed, 50 insertions(+)

diff --git a/grub-core/commands/menuentry.c b/grub-core/commands/menuentry.c
index 720e6d8ea..c40b27d8b 100644
--- a/grub-core/commands/menuentry.c
+++ b/grub-core/commands/menuentry.c
@@ -43,6 +43,9 @@ static const struct grub_arg_option options[] =
        anyone can boot it.  */
     {"unrestricted", 0, 0, N_("This entry can be booted by any user."),
      0, ARG_TYPE_NONE},
+    {"menutitle", 0, 0,
+     N_("Use STRING as menu title. When omitted, use the entry label."),
+     N_("TITLE"), ARG_TYPE_STRING},
     {0, 0, 0, 0, 0, 0}
   };
 
@@ -252,12 +255,46 @@ setparams_prefix (int argc, char **args)
   return result;
 }
 
+static char *
+menutitle_prefix (char *old_prefix, const char *title)
+{
+  const char *t;
+  char *p;
+  char *result;
+  grub_size_t len = 22;
+  grub_size_t old_len = grub_strlen (old_prefix);
+
+  /* Count resulting string length. */
+  for (t = title; *t; t++)
+    {
+      len += (*t++ == '\'' ? 4 : 1);
+    }
+
+  result = grub_malloc (old_len + len + 2);
+  if (! result)
+    return 0;
+
+  p = result;
+  grub_strcpy (p, old_prefix);
+  p = result + old_len;
+  grub_strcpy (p, "set grub_menu_title='");
+  p += 21;
+
+  p = grub_strchrsub (p, title, '\'', "'\\''");
+  *p++ = '\'';
+  *p++ = '\n';
+  *p = '\0';
+
+  return result;
+}
+
 static grub_err_t
 grub_cmd_menuentry (grub_extcmd_context_t ctxt, int argc, char **args)
 {
   char ch;
   char *src;
   char *prefix;
+  char *old_prefix;
   unsigned len;
   grub_err_t r;
   const char *users;
@@ -299,6 +336,19 @@ grub_cmd_menuentry (grub_extcmd_context_t ctxt, int argc, char **args)
   if (! prefix)
     return grub_errno;
 
+  /* Prepend the menu title line. */
+  if (ctxt->state[6].arg)
+    {
+      old_prefix = prefix;
+      prefix = menutitle_prefix (old_prefix,
+				 (ctxt->state[6].arg
+				  && grub_strlen(ctxt->state[6].arg) > 0)
+				 ? ctxt->state[6].arg : args[0]);
+      if (! prefix)
+	return grub_errno;
+      grub_free(old_prefix);
+    }
+
   r = grub_normal_add_menu_entry (argc - 1, (const char **) args,
 				  ctxt->state[0].args, ctxt->state[4].arg,
 				  users,
-- 
2.45.3


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Re: [PATCH 2/3] Option to set title of submenus

[sudhakar]

On 2025-05-26 23:48, Jiří Wolker via Grub-devel wrote:
> ---
>  grub-core/commands/menuentry.c | 50 ++++++++++++++++++++++++++++++++++
>  1 file changed, 50 insertions(+)
> 
> diff --git a/grub-core/commands/menuentry.c 
> b/grub-core/commands/menuentry.c
> index 720e6d8ea..c40b27d8b 100644
> --- a/grub-core/commands/menuentry.c
> +++ b/grub-core/commands/menuentry.c
> @@ -43,6 +43,9 @@ static const struct grub_arg_option options[] =
>         anyone can boot it.  */
>      {"unrestricted", 0, 0, N_("This entry can be booted by any 
> user."),
>       0, ARG_TYPE_NONE},
> +    {"menutitle", 0, 0,
> +     N_("Use STRING as menu title. When omitted, use the entry 
> label."),
> +     N_("TITLE"), ARG_TYPE_STRING},
>      {0, 0, 0, 0, 0, 0}
>    };
> 
> @@ -252,12 +255,46 @@ setparams_prefix (int argc, char **args)
>    return result;
>  }
> 
> +static char *
> +menutitle_prefix (char *old_prefix, const char *title)
> +{
> +  const char *t;
> +  char *p;
> +  char *result;
> +  grub_size_t len = 22;
> +  grub_size_t old_len = grub_strlen (old_prefix);
> +
> +  /* Count resulting string length. */
> +  for (t = title; *t; t++)
> +    {
> +      len += (*t++ == '\'' ? 4 : 1);
> +    }
> +

remove the brackets in one liner For loop

> +  result = grub_malloc (old_len + len + 2);
> +  if (! result)

s/! result/!result

> +    return 0;
> +
> +  p = result;
> +  grub_strcpy (p, old_prefix);
> +  p = result + old_len;
> +  grub_strcpy (p, "set grub_menu_title='");
> +  p += 21;
> +
> +  p = grub_strchrsub (p, title, '\'', "'\\''");
> +  *p++ = '\'';
> +  *p++ = '\n';
> +  *p = '\0';
> +
> +  return result;
> +}
> +
>  static grub_err_t
>  grub_cmd_menuentry (grub_extcmd_context_t ctxt, int argc, char **args)
>  {
>    char ch;
>    char *src;
>    char *prefix;
> +  char *old_prefix;
>    unsigned len;
>    grub_err_t r;
>    const char *users;
> @@ -299,6 +336,19 @@ grub_cmd_menuentry (grub_extcmd_context_t ctxt,
> int argc, char **args)
>    if (! prefix)
>      return grub_errno;
> 
s/! prefix/!prefix

> +  /* Prepend the menu title line. */
> +  if (ctxt->state[6].arg)
> +    {
> +      old_prefix = prefix;
> +      prefix = menutitle_prefix (old_prefix,
> +				 (ctxt->state[6].arg
> +				  && grub_strlen(ctxt->state[6].arg) > 0)
> +				 ? ctxt->state[6].arg : args[0]);
> +      if (! prefix)

ditto

> +	return grub_errno;
> +      grub_free(old_prefix);
> +    }
> +
>    r = grub_normal_add_menu_entry (argc - 1, (const char **) args,
>  				  ctxt->state[0].args, ctxt->state[4].arg,
>  				  users,

Indentation looks off in couple of places. Please fix it.

Thanks,
Sudhakar

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