monitor: Add `clear` command

[PATCH] monitor: Add `clear` command

Posted by AlanoSong@163.com 2 days, 23 hours ago

The monitor screen can be cluttered after executing commands
like `info qtree`. It is useful to have a command to clear
current screen, just like linux `clear` command do.

This patch has been tested under monitors using stdio, vc,
tcp socket, unix socket and serial interfaces.

Signed-off-by: Alano Song <AlanoSong@163.com>
---
 hmp-commands.hx       | 14 ++++++++++++++
 include/monitor/hmp.h |  1 +
 monitor/hmp-cmds.c    |  5 +++++
 3 files changed, 20 insertions(+)

diff --git a/hmp-commands.hx b/hmp-commands.hx
index 5cc4788f12..95f9166732 100644
--- a/hmp-commands.hx
+++ b/hmp-commands.hx
@@ -20,6 +20,20 @@ SRST
   Show the help for all commands or just for command *cmd*.
 ERST
 
+    {
+        .name       = "clear",
+        .args_type  = "",
+        .params     = "",
+        .help       = "clear the monitor screen",
+        .cmd        = hmp_clear,
+        .flags      = "p",
+    },
+
+SRST
+``clear``
+  Clear the monitor screen.
+ERST
+
     {
         .name       = "commit",
         .args_type  = "device:B",
diff --git a/include/monitor/hmp.h b/include/monitor/hmp.h
index e222bea60c..9b66458d21 100644
--- a/include/monitor/hmp.h
+++ b/include/monitor/hmp.h
@@ -165,6 +165,7 @@ void hmp_trace_event(Monitor *mon, const QDict *qdict);
 void hmp_trace_file(Monitor *mon, const QDict *qdict);
 void hmp_info_trace_events(Monitor *mon, const QDict *qdict);
 void hmp_help(Monitor *mon, const QDict *qdict);
+void hmp_clear(Monitor *mon, const QDict *qdict);
 void hmp_info_help(Monitor *mon, const QDict *qdict);
 void hmp_info_sync_profile(Monitor *mon, const QDict *qdict);
 void hmp_info_history(Monitor *mon, const QDict *qdict);
diff --git a/monitor/hmp-cmds.c b/monitor/hmp-cmds.c
index bc26b39d70..3e9485478e 100644
--- a/monitor/hmp-cmds.c
+++ b/monitor/hmp-cmds.c
@@ -218,6 +218,11 @@ void hmp_help(Monitor *mon, const QDict *qdict)
     hmp_help_cmd(mon, qdict_get_try_str(qdict, "name"));
 }
 
+void hmp_clear(Monitor *mon, const QDict *qdict)
+{
+    monitor_printf(mon, "\x1b[3J\x1b[2J\x1b[H");
+}
+
 void hmp_info_help(Monitor *mon, const QDict *qdict)
 {
     hmp_help_cmd(mon, "info");
-- 
2.43.0

Re: [PATCH] monitor: Add `clear` command

Posted by Dr. David Alan Gilbert 2 days, 19 hours ago

* AlanoSong@163.com (AlanoSong@163.com) wrote:
> The monitor screen can be cluttered after executing commands
> like `info qtree`. It is useful to have a command to clear
> current screen, just like linux `clear` command do.
> 
> This patch has been tested under monitors using stdio, vc,
> tcp socket, unix socket and serial interfaces.
> 
> Signed-off-by: Alano Song <AlanoSong@163.com>

Does typing ctrl-l not do it for you in your terminal?

Dave

> ---
>  hmp-commands.hx       | 14 ++++++++++++++
>  include/monitor/hmp.h |  1 +
>  monitor/hmp-cmds.c    |  5 +++++
>  3 files changed, 20 insertions(+)
> 
> diff --git a/hmp-commands.hx b/hmp-commands.hx
> index 5cc4788f12..95f9166732 100644
> --- a/hmp-commands.hx
> +++ b/hmp-commands.hx
> @@ -20,6 +20,20 @@ SRST
>    Show the help for all commands or just for command *cmd*.
>  ERST
>  
> +    {
> +        .name       = "clear",
> +        .args_type  = "",
> +        .params     = "",
> +        .help       = "clear the monitor screen",
> +        .cmd        = hmp_clear,
> +        .flags      = "p",
> +    },
> +
> +SRST
> +``clear``
> +  Clear the monitor screen.
> +ERST
> +
>      {
>          .name       = "commit",
>          .args_type  = "device:B",
> diff --git a/include/monitor/hmp.h b/include/monitor/hmp.h
> index e222bea60c..9b66458d21 100644
> --- a/include/monitor/hmp.h
> +++ b/include/monitor/hmp.h
> @@ -165,6 +165,7 @@ void hmp_trace_event(Monitor *mon, const QDict *qdict);
>  void hmp_trace_file(Monitor *mon, const QDict *qdict);
>  void hmp_info_trace_events(Monitor *mon, const QDict *qdict);
>  void hmp_help(Monitor *mon, const QDict *qdict);
> +void hmp_clear(Monitor *mon, const QDict *qdict);
>  void hmp_info_help(Monitor *mon, const QDict *qdict);
>  void hmp_info_sync_profile(Monitor *mon, const QDict *qdict);
>  void hmp_info_history(Monitor *mon, const QDict *qdict);
> diff --git a/monitor/hmp-cmds.c b/monitor/hmp-cmds.c
> index bc26b39d70..3e9485478e 100644
> --- a/monitor/hmp-cmds.c
> +++ b/monitor/hmp-cmds.c
> @@ -218,6 +218,11 @@ void hmp_help(Monitor *mon, const QDict *qdict)
>      hmp_help_cmd(mon, qdict_get_try_str(qdict, "name"));
>  }
>  
> +void hmp_clear(Monitor *mon, const QDict *qdict)
> +{
> +    monitor_printf(mon, "\x1b[3J\x1b[2J\x1b[H");
> +}
> +
>  void hmp_info_help(Monitor *mon, const QDict *qdict)
>  {
>      hmp_help_cmd(mon, "info");
> -- 
> 2.43.0
> 
-- 
 -----Open up your eyes, open up your mind, open up your code -------   
/ Dr. David Alan Gilbert    |       Running GNU/Linux       | Happy  \ 
\        dave @ treblig.org |                               | In Hex /
 \ _________________________|_____ http://www.treblig.org   |_______/

Re: [PATCH] monitor: Add `clear` command

Posted by Alano Song 23 hours ago

At 2026-04-19 01:23:46, "Dr. David Alan Gilbert" <dave@treblig.org> wrote:
>* AlanoSong@163.com (AlanoSong@163.com) wrote:
>> The monitor screen can be cluttered after executing commands
>> like `info qtree`. It is useful to have a command to clear
>> current screen, just like linux `clear` command do.
>> 
>> This patch has been tested under monitors using stdio, vc,
>> tcp socket, unix socket and serial interfaces.
>> 
>> Signed-off-by: Alano Song <AlanoSong@163.com>
>
>Does typing ctrl-l not do it for you in your terminal?
>
>Dave
>


Yes, you are correct that ctrl-l provides basic screen clear,
but the new `clear` command clears both visible screen and
scrollback buffer, just like `clear` command does on my Ubuntu terminal.

I still believe that this patch is useful:
1) Many linux users like me instinctively type `clear`,
when we want to tidy up the terminal.
2) Not everyone is aware of or remembers the ctrl-l shortcut.
   A typed command is more discoverable, especially for new users
   or those who don't use terminal shortcuts regularly.

Best Regards,
Alano.

// Re-send, it seems that the previous reply email is not visible in the mail list.


>> ---
>>  hmp-commands.hx       | 14 ++++++++++++++
>>  include/monitor/hmp.h |  1 +
>>  monitor/hmp-cmds.c    |  5 +++++
>>  3 files changed, 20 insertions(+)
>> 
>> diff --git a/hmp-commands.hx b/hmp-commands.hx
>> index 5cc4788f12..95f9166732 100644
>> --- a/hmp-commands.hx
>> +++ b/hmp-commands.hx
>> @@ -20,6 +20,20 @@ SRST
>>    Show the help for all commands or just for command *cmd*.
>>  ERST
>>  
>> +    {
>> +        .name       = "clear",
>> +        .args_type  = "",
>> +        .params     = "",
>> +        .help       = "clear the monitor screen",
>> +        .cmd        = hmp_clear,
>> +        .flags      = "p",
>> +    },
>> +
>> +SRST
>> +``clear``
>> +  Clear the monitor screen.
>> +ERST
>> +
>>      {
>>          .name       = "commit",
>>          .args_type  = "device:B",
>> diff --git a/include/monitor/hmp.h b/include/monitor/hmp.h
>> index e222bea60c..9b66458d21 100644
>> --- a/include/monitor/hmp.h
>> +++ b/include/monitor/hmp.h
>> @@ -165,6 +165,7 @@ void hmp_trace_event(Monitor *mon, const QDict *qdict);
>>  void hmp_trace_file(Monitor *mon, const QDict *qdict);
>>  void hmp_info_trace_events(Monitor *mon, const QDict *qdict);
>>  void hmp_help(Monitor *mon, const QDict *qdict);
>> +void hmp_clear(Monitor *mon, const QDict *qdict);
>>  void hmp_info_help(Monitor *mon, const QDict *qdict);
>>  void hmp_info_sync_profile(Monitor *mon, const QDict *qdict);
>>  void hmp_info_history(Monitor *mon, const QDict *qdict);
>> diff --git a/monitor/hmp-cmds.c b/monitor/hmp-cmds.c
>> index bc26b39d70..3e9485478e 100644
>> --- a/monitor/hmp-cmds.c
>> +++ b/monitor/hmp-cmds.c
>> @@ -218,6 +218,11 @@ void hmp_help(Monitor *mon, const QDict *qdict)
>>      hmp_help_cmd(mon, qdict_get_try_str(qdict, "name"));
>>  }
>>  
>> +void hmp_clear(Monitor *mon, const QDict *qdict)
>> +{
>> +    monitor_printf(mon, "\x1b[3J\x1b[2J\x1b[H");
>> +}
>> +
>>  void hmp_info_help(Monitor *mon, const QDict *qdict)
>>  {
>>      hmp_help_cmd(mon, "info");
>> -- 
>> 2.43.0
>> 
>-- 
> -----Open up your eyes, open up your mind, open up your code -------   
>/ Dr. David Alan Gilbert    |       Running GNU/Linux       | Happy  \ 
>\        dave @ treblig.org |                               | In Hex /
> \ _________________________|_____ http://www.treblig.org   |_______/

Re:Re: [PATCH] monitor: Add `clear` command

Posted by Alano Song 2 days, 5 hours ago

At 2026-04-19 01:23:46, "Dr. David Alan Gilbert" <dave@treblig.org> wrote:
>* AlanoSong@163.com (AlanoSong@163.com) wrote:
>> The monitor screen can be cluttered after executing commands
>> like `info qtree`. It is useful to have a command to clear
>> current screen, just like linux `clear` command do.
>> 
>> This patch has been tested under monitors using stdio, vc,
>> tcp socket, unix socket and serial interfaces.
>> 
>> Signed-off-by: Alano Song <AlanoSong@163.com>
>
>Does typing ctrl-l not do it for you in your terminal?
>
>Dave
>


Yes, you are correct that ctrl-l provides basic screen clear,
but the new `clear` command clears both visible screen and
scrollback buffer, just like `clear` command does on my Ubuntu terminal.

I still believe that this patch is useful:
1) Many linux users like me instinctively type `clear`
when we want to tidy up the terminal.
2) Not everyone is aware of or remembers the ctrl-l shortcut.
   A typed command is more discoverable, especially for new users
   or those who don't use terminal shortcuts regularly.


>> ---
>>  hmp-commands.hx       | 14 ++++++++++++++
>>  include/monitor/hmp.h |  1 +
>>  monitor/hmp-cmds.c    |  5 +++++
>>  3 files changed, 20 insertions(+)
>> 
>> diff --git a/hmp-commands.hx b/hmp-commands.hx
>> index 5cc4788f12..95f9166732 100644
>> --- a/hmp-commands.hx
>> +++ b/hmp-commands.hx
>> @@ -20,6 +20,20 @@ SRST
>>    Show the help for all commands or just for command *cmd*.
>>  ERST
>>  
>> +    {
>> +        .name       = "clear",
>> +        .args_type  = "",
>> +        .params     = "",
>> +        .help       = "clear the monitor screen",
>> +        .cmd        = hmp_clear,
>> +        .flags      = "p",
>> +    },
>> +
>> +SRST
>> +``clear``
>> +  Clear the monitor screen.
>> +ERST
>> +
>>      {
>>          .name       = "commit",
>>          .args_type  = "device:B",
>> diff --git a/include/monitor/hmp.h b/include/monitor/hmp.h
>> index e222bea60c..9b66458d21 100644
>> --- a/include/monitor/hmp.h
>> +++ b/include/monitor/hmp.h
>> @@ -165,6 +165,7 @@ void hmp_trace_event(Monitor *mon, const QDict *qdict);
>>  void hmp_trace_file(Monitor *mon, const QDict *qdict);
>>  void hmp_info_trace_events(Monitor *mon, const QDict *qdict);
>>  void hmp_help(Monitor *mon, const QDict *qdict);
>> +void hmp_clear(Monitor *mon, const QDict *qdict);
>>  void hmp_info_help(Monitor *mon, const QDict *qdict);
>>  void hmp_info_sync_profile(Monitor *mon, const QDict *qdict);
>>  void hmp_info_history(Monitor *mon, const QDict *qdict);
>> diff --git a/monitor/hmp-cmds.c b/monitor/hmp-cmds.c
>> index bc26b39d70..3e9485478e 100644
>> --- a/monitor/hmp-cmds.c
>> +++ b/monitor/hmp-cmds.c
>> @@ -218,6 +218,11 @@ void hmp_help(Monitor *mon, const QDict *qdict)
>>      hmp_help_cmd(mon, qdict_get_try_str(qdict, "name"));
>>  }
>>  
>> +void hmp_clear(Monitor *mon, const QDict *qdict)
>> +{
>> +    monitor_printf(mon, "\x1b[3J\x1b[2J\x1b[H");
>> +}
>> +
>>  void hmp_info_help(Monitor *mon, const QDict *qdict)
>>  {
>>      hmp_help_cmd(mon, "info");
>> -- 
>> 2.43.0
>> 
>-- 
> -----Open up your eyes, open up your mind, open up your code -------   
>/ Dr. David Alan Gilbert    |       Running GNU/Linux       | Happy  \ 
>\        dave @ treblig.org |                               | In Hex /
> \ _________________________|_____ http://www.treblig.org   |_______/

Re: [PATCH] monitor: Add `clear` command

Posted by Paolo Bonzini 2 days, 4 hours ago

On 4/18/26 19:23, Dr. David Alan Gilbert wrote:
> * AlanoSong@163.com (AlanoSong@163.com) wrote:
>> The monitor screen can be cluttered after executing commands
>> like `info qtree`. It is useful to have a command to clear
>> current screen, just like linux `clear` command do.
>>
>> This patch has been tested under monitors using stdio, vc,
>> tcp socket, unix socket and serial interfaces.
>>
>> Signed-off-by: Alano Song <AlanoSong@163.com>
> 
> Does typing ctrl-l not do it for you in your terminal?

Yeah, we should add support for Ctrl-L to the non-terminal backends 
independent of this.  However, backends such as socket do not use 
readline so they also don't support it right now.

Paolo

> Dave
> 
>> ---
>>   hmp-commands.hx       | 14 ++++++++++++++
>>   include/monitor/hmp.h |  1 +
>>   monitor/hmp-cmds.c    |  5 +++++
>>   3 files changed, 20 insertions(+)
>>
>> diff --git a/hmp-commands.hx b/hmp-commands.hx
>> index 5cc4788f12..95f9166732 100644
>> --- a/hmp-commands.hx
>> +++ b/hmp-commands.hx
>> @@ -20,6 +20,20 @@ SRST
>>     Show the help for all commands or just for command *cmd*.
>>   ERST
>>   
>> +    {
>> +        .name       = "clear",
>> +        .args_type  = "",
>> +        .params     = "",
>> +        .help       = "clear the monitor screen",
>> +        .cmd        = hmp_clear,
>> +        .flags      = "p",
>> +    },
>> +
>> +SRST
>> +``clear``
>> +  Clear the monitor screen.
>> +ERST
>> +
>>       {
>>           .name       = "commit",
>>           .args_type  = "device:B",
>> diff --git a/include/monitor/hmp.h b/include/monitor/hmp.h
>> index e222bea60c..9b66458d21 100644
>> --- a/include/monitor/hmp.h
>> +++ b/include/monitor/hmp.h
>> @@ -165,6 +165,7 @@ void hmp_trace_event(Monitor *mon, const QDict *qdict);
>>   void hmp_trace_file(Monitor *mon, const QDict *qdict);
>>   void hmp_info_trace_events(Monitor *mon, const QDict *qdict);
>>   void hmp_help(Monitor *mon, const QDict *qdict);
>> +void hmp_clear(Monitor *mon, const QDict *qdict);
>>   void hmp_info_help(Monitor *mon, const QDict *qdict);
>>   void hmp_info_sync_profile(Monitor *mon, const QDict *qdict);
>>   void hmp_info_history(Monitor *mon, const QDict *qdict);
>> diff --git a/monitor/hmp-cmds.c b/monitor/hmp-cmds.c
>> index bc26b39d70..3e9485478e 100644
>> --- a/monitor/hmp-cmds.c
>> +++ b/monitor/hmp-cmds.c
>> @@ -218,6 +218,11 @@ void hmp_help(Monitor *mon, const QDict *qdict)
>>       hmp_help_cmd(mon, qdict_get_try_str(qdict, "name"));
>>   }
>>   
>> +void hmp_clear(Monitor *mon, const QDict *qdict)
>> +{
>> +    monitor_printf(mon, "\x1b[3J\x1b[2J\x1b[H");
>> +}
>> +
>>   void hmp_info_help(Monitor *mon, const QDict *qdict)
>>   {
>>       hmp_help_cmd(mon, "info");
>> -- 
>> 2.43.0
>>