Hello, list,
I wish to know, how to send a "BREAK" to trigger the sysreq functions on the
serial line, using echo.
I mean like this:
#!/bin/bash
echo "?BREAK?" >/dev/ttyS0
sleep 2
echo "m" >/dev/ttyS0
Thanks,
Janos
On 05/27/06 02:58:44PM +0200, Haar J?nos wrote:
> Hello, list,
>
> I wish to know, how to send a "BREAK" to trigger the sysreq functions on the
> serial line, using echo.
>
> I mean like this:
>
> #!/bin/bash
> echo "?BREAK?" >/dev/ttyS0
> sleep 2
> echo "m" >/dev/ttyS0
>
Is there a reason you can't use "echo -n m > /proc/sysrq-trigger"?
Jim.
Followup to: <01b701c6818d$4bcd37b0$1800a8c0@dcccs>
By author: =?iso-8859-2?Q?Haar_J=E1nos?= <[email protected]>
In newsgroup: linux.dev.kernel
>
> Hello, list,
>
> I wish to know, how to send a "BREAK" to trigger the sysreq functions on the
> serial line, using echo.
>
> I mean like this:
>
> #!/bin/bash
> echo "?BREAK?" >/dev/ttyS0
> sleep 2
> echo "m" >/dev/ttyS0
>
You can't use it using echo, however, you can do it using Perl:
perl -e 'use POSIX; tcsendbreak(1,0);' > /dev/ttyS0
-hpa
"H. Peter Anvin" <[email protected]> az al?bbiakat ?rta a k?vetkezo ?zenetben
news:[email protected]...
> Followup to: <01b701c6818d$4bcd37b0$1800a8c0@dcccs>
> By author: =?iso-8859-2?Q?Haar_J=E1nos?= <[email protected]>
> In newsgroup: linux.dev.kernel
> >
> > Hello, list,
> >
> > I wish to know, how to send a "BREAK" to trigger the sysreq functions on
the
> > serial line, using echo.
> >
> > I mean like this:
> >
> > #!/bin/bash
> > echo "?BREAK?" >/dev/ttyS0
> > sleep 2
> > echo "m" >/dev/ttyS0
> >
>
> You can't use it using echo, however, you can do it using Perl:
>
> perl -e 'use POSIX; tcsendbreak(1,0);' > /dev/ttyS0
Ahh, thats what i am waiting for, thanks! :-)
Works fine!
Thanks,
Janos
>
> -hpa
> -
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> Please read the FAQ at http://www.tux.org/lkml/
On Sat, 27 May 2006, [iso-8859-2] Haar J?nos wrote:
> Hello, list,
>
> I wish to know, how to send a "BREAK" to trigger the sysreq functions on the
> serial line, using echo.
>
> I mean like this:
>
> #!/bin/bash
> echo "?BREAK?" >/dev/ttyS0
> sleep 2
> echo "m" >/dev/ttyS0
>
> Thanks,
> Janos
>
Can't you use /proc/sysrq-trigger?
Cheers,
Dick Johnson
Penguin : Linux version 2.6.16.4 on an i686 machine (5592.73 BogoMips).
New book: http://www.AbominableFirebug.com/
_
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Thank you.
On Mon, 29 May 2006 11:08:15 EDT, "linux-os (Dick Johnson)" said:
>
> On Sat, 27 May 2006, [iso-8859-2] Haar J?nos wrote:
>
> > Hello, list,
> >
> > I wish to know, how to send a "BREAK" to trigger the sysreq functions on the
> > serial line, using echo.
> >
> > I mean like this:
> >
> > #!/bin/bash
> > echo "?BREAK?" >/dev/ttyS0
> > sleep 2
> > echo "m" >/dev/ttyS0
> >
> > Thanks,
> > Janos
> >
>
> Can't you use /proc/sysrq-trigger?
That can be tricky if the other end of /dev/ttyS0 is plugged into a debugging
serial port on an embedded system where you don't have easy access to a shell.
Or for that matter, if you're trying to talk to the serial port on a non-embedded
system, which is too far into OOM thrashing for you to be able to get a
usable shell prompt.....
----- Original Message -----
From: <[email protected]>
To: "linux-os (Dick Johnson)" <[email protected]>
Cc: "Haar J?nos" <[email protected]>; <[email protected]>
Sent: Monday, May 29, 2006 5:35 PM
Subject: Re: How to send a break?
On Mon, 29 May 2006 11:08:15 EDT, "linux-os (Dick Johnson)" said:
>
> On Sat, 27 May 2006, [iso-8859-2] Haar J?nos wrote:
>
> > Hello, list,
> >
> > I wish to know, how to send a "BREAK" to trigger the sysreq functions on
the
> > serial line, using echo.
> >
> > I mean like this:
> >
> > #!/bin/bash
> > echo "?BREAK?" >/dev/ttyS0
> > sleep 2
> > echo "m" >/dev/ttyS0
> >
> > Thanks,
> > Janos
> >
>
> Can't you use /proc/sysrq-trigger?
> That can be tricky if the other end of /dev/ttyS0 is plugged into a
debugging
> serial port on an embedded system where you don't have easy access to a
shell.
> Or for that matter, if you're trying to talk to the serial port on a
non-embedded
> system, which is too far into OOM thrashing for you to be able to get a
> usable shell prompt.....
This is for debugging an frozen X86_64 system! :-)
Thanks,
Janos