As far as running it, here's what mine currently looks like:
# tty1 - getty
#
# This service maintains a getty on tty1 from the point the system is
# started until it is shut down again.
start on stopped rc RUNLEVEL=[2345] and (
not-container or
container CONTAINER=lxc or
container CONTAINER=lxc-libvirt)
stop on runlevel [!2345]
respawn
exec /sbin/getty -8 38400 tty1
Change that final line to something like:
exec /path/to/your/script.pl < /dev/tty1 > /dev/tty1
Note that the respawn keyword above will cause your script to be
re-executed if it ever dies.
On Mon, Aug 31, 2015 at 2:01 PM, Curt Lundgren <[email protected]> wrote:
> Thanks, Tilghman - I'm going to try it.
>
> On Mon, Aug 31, 2015 at 1:59 PM, Tilghman Lesher <[email protected]>
> wrote:
>>
>> No, essentially your program is REPLACING the login prompt. Instead
>> of the login program running on tty1, your Perl program will start;
>> the keyboard (wedge) will go to the Perl program's stdin, and stdout
>> will go to that virtual screen. If you did ever connect a screen to
>> that Pi, the output of your program is what would be displayed there.
>>
>> On Mon, Aug 31, 2015 at 1:55 PM, Curt Lundgren <[email protected]> wrote:
>> > My specific worry is will the program (Perl) be hit with a login prompt?
>> > I
>> > was thinking if that's the case I could use a couple of reject cards,
>> > misprints, etc. as user name and password. Tap one, then the other to
>> > get
>> > logged in. Am I overthinking this?
>> >
>> > On Mon, Aug 31, 2015 at 1:53 PM, Tilghman Lesher <[email protected]>
>> > wrote:
>> >>
>> >> What language is your current program written in?
>> >>
>> >> It should work being invoked from init, although how init invokes it
>> >> is different based upon which init program is running on the system.
>> >> On Ubuntu 12.04, the file to edit is /etc/init/tty1.conf. Once it's
>> >> running, just read from STDIN.
>> >>
>> >> On Mon, Aug 31, 2015 at 1:47 PM, Curt Lundgren <[email protected]>
>> >> wrote:
>> >> > It's a generic USB reader for Mifare 1K Classic cards. The reader
>> >> > puts
>> >> > out
>> >> > a 13.5 MHz field which is picked up by a few turns of wire embedded
>> >> > in
>> >> > the
>> >> > card. The field provides power to the chip, which can then do
>> >> > bidirectional
>> >> > communication with the reader. This is a simple reader that only
>> >> > grabs
>> >> > the
>> >> > CSN, card serial number. It's a 32-bit code which this reader gives
>> >> > me
>> >> > as 8
>> >> > hexadecimal digits. The range of the card/reader is about 1-1/2" so
>> >> > a
>> >> > 'tap'
>> >> > of the card on the reader yields a solid read every time.
>> >> >
>> >> > It's HID, so it outputs 'scan codes' as detailed above. Tilghman
>> >> > offers
>> >> > an
>> >> > interesting approach, still not quite sure how I'd go about that.
>> >> >
>> >> > If these were Hollerith cards, you'd have to call me Hangin' Chad…
>> >> >
>> >> > On Mon, Aug 31, 2015 at 1:24 PM, Jack Coats <[email protected]> wrote:
>> >> >>
>> >> >> I am to old... I thought you were talking 80 or (the smaller) 96
>> >> >> column
>> >> >> cards! ... Many of those readers put out EBCDIC instead of ASCII.
>> >> >> But as always, I digress into ancient history when mainframes roamed
>> >> >> the
>> >> >> earth.
>> >> >>
>> >> >> Now that I am past the 20th century in my thinking, what flavor of
>> >> >> card
>> >> >> reader are you using? How is it connected?
>> >> >>
>> >> >> On Sun, Aug 30, 2015 at 8:19 PM, Tilghman Lesher
>> >> >> <[email protected]>
>> >> >> wrote:
>> >> >>>
>> >> >>> Sounds like what you're talking about is that the device is acting
>> >> >>> as
>> >> >>> a keyboard wedge -- that is, it's inserting a stream of characters
>> >> >>> into the keyboard buffer, probably through its device driver. I
>> >> >>> have
>> >> >>> a magnetic card reader here that works in precisely the same way.
>> >> >>>
>> >> >>> The long and short of it is that your program would need to be
>> >> >>> running
>> >> >>> in the foreground; that is, having its stdin being supplied by the
>> >> >>> console. Probably the best way to do this in Linux on boot would
>> >> >>> be
>> >> >>> to have your program run directly from init, associated with tty1,
>> >> >>> NOT
>> >> >>> background itself, and as long as the machine stays on that
>> >> >>> terminal
>> >> >>> device (and it should), your program should get all keyboard input
>> >> >>> directly from stdin (fd 0).
>> >> >>>
>> >> >>>
>> >> >>> On Sun, Aug 30, 2015 at 8:01 PM, Curt Lundgren <[email protected]>
>> >> >>> wrote:
>> >> >>> > I'm working on a program for a Raspberry Pi (one of the cool new
>> >> >>> > ones
>> >> >>> > with
>> >> >>> > the quad-core CPU and a gigabyte of RAM). The program will run
>> >> >>> > as a
>> >> >>> > daemon
>> >> >>> > and this unit is headless - there's no keyboard plugged in. Just
>> >> >>> > a
>> >> >>> > USB
>> >> >>> > Mifare HID card reader that outputs 8 hex characters when a card
>> >> >>> > is
>> >> >>> > in
>> >> >>> > proximity, then an 'Enter.'
>> >> >>> >
>> >> >>> > It's actually outputting scan codes, but I figure I can convert
>> >> >>> > them
>> >> >>> > to
>> >> >>> > the
>> >> >>> > appropriate hex codes.
>> >> >>> >
>> >> >>> > I understand if I was running on the console, tapping a card on
>> >> >>> > the
>> >> >>> > reader
>> >> >>> > would cause the hex string to be input wherever my cursor is.
>> >> >>> > I'd
>> >> >>> > love
>> >> >>> > to
>> >> >>> > be able to redirect that input to my program, but I'm clueless on
>> >> >>> > how
>> >> >>> > that's
>> >> >>> > done. My google-fu isn't working for me here either.
>> >> >>> >
>> >> >>> > The card reader does show up as /dev/input/event0 and if I cat
>> >> >>> > that,
>> >> >>> > it
>> >> >>> > outputs a bunch of binary stuff. I can send it to a file and a
>> >> >>> > hex
>> >> >>> > dump of
>> >> >>> > part of that file looks like this:
>> >> >>> >
>> >> >>> > 00000000: eba1 e355 6032 0600 0400 0400 2700 0700
>> >> >>> > ...U`2......'...
>> >> >>> > 00000010: eba1 e355 6032 0600 0100 0b00 0100 0000
>> >> >>> > ...U`2..........
>> >> >>> > 00000020: eba1 e355 6032 0600 0000 0000 0000 0000
>> >> >>> > ...U`2..........
>> >> >>> > 00000030: eba1 e355 7251 0600 0400 0400 2700 0700
>> >> >>> > ...UrQ......'...
>> >> >>> > 00000040: eba1 e355 7251 0600 0100 0b00 0000 0000
>> >> >>> > ...UrQ..........
>> >> >>> > 00000050: eba1 e355 7251 0600 0000 0000 0000 0000
>> >> >>> > ...UrQ..........
>> >> >>> > 00000060: eba1 e355 ad70 0600 0400 0400 1f00 0700
>> >> >>> > ...U.p..........
>> >> >>> > 00000070: eba1 e355 ad70 0600 0100 0300 0100 0000
>> >> >>> > ...U.p..........
>> >> >>> > 00000080: eba1 e355 ad70 0600 0000 0000 0000 0000
>> >> >>> > ...U.p..........
>> >> >>> > 00000090: eba1 e355 e48f 0600 0400 0400 1f00 0700
>> >> >>> > ...U............
>> >> >>> > 000000a0: eba1 e355 e48f 0600 0100 0300 0000 0000
>> >> >>> > ...U............
>> >> >>> > 000000b0: eba1 e355 e48f 0600 0000 0000 0000 0000
>> >> >>> > ...U............
>> >> >>> > 000000c0: eba1 e355 26af 0600 0400 0400 2400 0700
>> >> >>> > ...U&.......$...
>> >> >>> > 000000d0: eba1 e355 26af 0600 0100 0800 0100 0000
>> >> >>> > ...U&...........
>> >> >>> > 000000e0: eba1 e355 26af 0600 0000 0000 0000 0000
>> >> >>> > ...U&...........
>> >> >>> > 000000f0: eba1 e355 64ce 0600 0400 0400 2400 0700
>> >> >>> > ...Ud.......$...
>> >> >>> > 00000100: eba1 e355 64ce 0600 0100 0800 0000 0000
>> >> >>> > ...Ud...........
>> >> >>> > 00000110: eba1 e355 64ce 0600 0000 0000 0000 0000
>> >> >>> > ...Ud...........
>> >> >>> >
>> >> >>> > Don't know if the formatting will display properly, but I've
>> >> >>> > bolded
>> >> >>> > a
>> >> >>> > few
>> >> >>> > bytes. The 0x27 is '0' and we see keypress and key release.
>> >> >>> > This
>> >> >>> > is
>> >> >>> > followed by 0x1F (2) and 0x24 (7) - we march through the rest of
>> >> >>> > the
>> >> >>> > string
>> >> >>> > and finally arrive at the 0x28 Enter key:
>> >> >>> >
>> >> >>> > 00000300: eba1 e355 3626 0800 0400 0400 2800 0700
>> >> >>> > ...U6&......(...
>> >> >>> > 00000310: eba1 e355 3626 0800 0100 1c00 0100 0000
>> >> >>> > ...U6&..........
>> >> >>> > 00000320: eba1 e355 3626 0800 0000 0000 0000 0000
>> >> >>> > ...U6&..........
>> >> >>> > 00000330: eba1 e355 9145 0800 0400 0400 2800 0700
>> >> >>> > ...U.E......(...
>> >> >>> > 00000340: eba1 e355 9145 0800 0100 1c00 0000 0000
>> >> >>> > ...U.E..........
>> >> >>> > 00000350: eba1 e355 9145 0800 0000 0000 0000 0000
>> >> >>> > ...U.E..........
>> >> >>> >
>> >> >>> > I don't pretend to understand scan codes, but 48 bytes for
>> >> >>> > keypress
>> >> >>> > and
>> >> >>> > another 48 for key release? Seems excessive, but it can be
>> >> >>> > handled.
>> >> >>> > The
>> >> >>> > hex 0x01 below the scan code is keypress, the 0x00 below the
>> >> >>> > other
>> >> >>> > scan
>> >> >>> > codes is key release.
>> >> >>> >
>> >> >>> > Questions: Can this data be grabbed from some convenient place
>> >> >>> > in
>> >> >>> > the
>> >> >>> > OS,
>> >> >>> > preferably as a nice 8-character string? What does the OS do
>> >> >>> > with
>> >> >>> > HID
>> >> >>> > input
>> >> >>> > when the Pi is running headless? The current plan says there
>> >> >>> > will
>> >> >>> > never be
>> >> >>> > a real keyboard plugged in, just the card reader.
>> >> >>> >
>> >> >>> > Does anyone know what Linux does with input from an HID device
>> >> >>> > when
>> >> >>> > there's
>> >> >>> > no session running from the console? Does it get intercepted by
>> >> >>> > a
>> >> >>> > login
>> >> >>> > screen?
>> >> >>> >
>> >> >>> > OS is Raspbian Wheezy, apparently version 7 on a 3.18.11 kernel.
>> >> >>> >
>> >> >>> > TIA
>> >> >>> >
>> >> >>> > Curt
>> >> >>> >
>> >> >>> > --
>> >> >>> > --
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>> >> >>> > To post to this group, send email to [email protected]
>> >> >>> > To unsubscribe from this group, send email to
>> >> >>> > [email protected]
>> >> >>> > For more options, visit this group at
>> >> >>> > http://groups.google.com/group/nlug-talk?hl=en
>> >> >>> >
>> >> >>> > ---
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>> >> >>> > send
>> >> >>> > an
>> >> >>> > email to [email protected].
>> >> >>> > For more options, visit https://groups.google.com/d/optout.
>> >> >>>
>> >> >>>
>> >> >>>
>> >> >>> --
>> >> >>> Tilghman
>> >> >>>
>> >> >>> --
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>> >> >>
>> >> >>
>> >> >>
>> >> >>
>> >> >> --
>> >> >> ><> ... Jack
>> >> >>
>> >> >> The Four Boxes of Liberty - "There are four boxes to be used in the
>> >> >> defense of liberty: soap, ballot, jury and ammo. Please use in that
>> >> >> order."
>> >> >> "Whatever you do, work at it with all your heart"... Colossians 3:23
>> >> >> "Anyone who has never made a mistake, has never tried anything new."
>> >> >> -
>> >> >> Albert Einstein
>> >> >> "You don't manage people; you manage things. You lead people." -
>> >> >> Admiral
>> >> >> Grace Hopper, USN
>> >> >> "Tell me and I forget. Teach me and I remember. Involve me and I
>> >> >> learn." -
>> >> >> Ben Franklin
>> >> >>
>> >> >> --
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>> >> >>
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>> >> >
>> >> >
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>> >>
>> >>
>> >> --
>> >> Tilghman
>> >>
>> >> --
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>> >
>> >
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>>
>>
>> --
>> Tilghman
>>
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>
>
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