Get numbers of all screens in Xlib - linux

I've been googling for quite a long time and I just can't find any information on how to get screen_number for every screen connected to computer. Here I found a list of macros and some of them (like for example ScreenOfDisplay(display, screen_number) ) use argument screen_number. However there is no such macro that could give me a list of those numbers (one for every connected screen). I know how to get number of default screen (DefaultScreen() ) and count of all screens ( ScreenCount() ) but what about other screens? I noticed that screen_number of default screen is 0, although I have only one screen connected to my computer so I can't really test what happens when there are more of them. I think that screen_number could be assigned in a very simple way which is screen_number=0 for first screen,screen_number=1 for second,screen_number=2 for third and so on but as I said... I can't test wheather it's true and even if I had multiple screens how could I be sure that it works like this for all computers .Please ,if anyone of you has more experience with X11 and knows all details about how it works,tell me if I am right.

The ScreenCount(dpy) macro and int XScreenCount(Display*) function both return the number of screens connected to the display. Valid screen numbers are 0 to ScreenCount(dpy)-1. Macros in Xlib.h confirm:
#define ScreenCount(dpy) (((_XPrivDisplay)dpy)->nscreens)
#define ScreenOfDisplay(dpy, scr) (&((_XPrivDisplay)dpy)->screens[scr])

Your source (2.2.1. Display Macros) provides enough information. Normally the default screen-number is 0, e.g., when connecting to the local host you could use :0.0 as indicated in the documentation for XOpenDisplay.
That is "normally". If you run VNC, normally that runs on a different display (the first 0 in the simple connection string shown).
But (reading the documentation), when an application calls XOpenDisplay, it asks for the given screen-number (which the X server may/may not honor):
screen_number
Specifies the screen to be used on that server. Multiple screens can be controlled by a single X server. The screen_number sets an internal variable that can be accessed by using the DefaultScreen() macro or the XDefaultScreen() function if you are using languages other than C (see "Display Macros").

Related

^HV Only returning some values

I'm trying to print some RFID tags and retrieve their TIDs to store them in my system and know which tags have been printed. Right now I'm reading the TID and sending it back to my computer (connected via USB with the my ZT421 printer) with the following code:
^RFR,H,0,12,2^FN0^FS^FH_^HV0,24,,_0D_0A,L^FS
^RFW,H,2,12,1^FD17171999ABABABAAAAAAAAAB^FS
This is repeated for each tag that I'm printing. However, when printing 10 tags, I only get 9 TIDs. If after that I try to print 7 tags, I still get 9 TIDs. To be honest I'm a bit lost now, because even trying to use the code examples from the ZPL manual (I've tried the ^RI instruction also) it doesn't seem to work.
The communication with the printer is beeing done through Zebra Setup Utilities' direct communication tool.
I tried to retrieve each printed tag TID with:
^RFR,H,0,12,2^FN0^FS^FH_^HV0,24,,_0D_0A,L^FS
^RFW,H,2,12,1^FD17171999ABABABAAAAAAAAAB^FS
but I always get 9 TIDs.
I also tried getting the TID with the ZPL manual example for the ^RI command:
^XA
^FO20,120^A0N,60^FN0^FS
^RI0,,5^FS
^HV0,,Tag ID:^FS
^XZ
And I got absolutely nothing returned to the computer, just a mssage saying "Tag ID:" and no value shown.
I would really appreciate some help with this...
Thanks in advance!
I've fixed the issue, but I'm going to leave the solution here just in case someone else is facing the same problem.
I thought that maybe it wasn't a code issue, but something related to the computer-printer communication. It turned out to be the case. The Zebra Setup Utilities program has a button that says "options". If you click it, a new screen will open and there you can configure the seconds that the program will wait for the printer response (in this case through USB). By default it's set to 5, i changed this value to 100, which is the maximum. This meant that instead of just printing and retrieving the TIDs of 6-9 tags, now I can do it for about 100.
This is not amazing because in my case it implied creating 25 files for the 2500 tags I had to print and store the TIDs, however it's far better than before.

Zebra RFD8500 : How to use read in ZETI

I have a Zebra RFD8500 here and I connected to it via the terminal. I am trying to use the ZETI command read to access epc's, but it does not read anything.
But if I use the ZETI command inventory it finds all the tags around.
Anyone knows how to use the read command properly? Also is there some kind of filter per default on?
I am using the developer example on page 174 Link to PDF
Not sure if you solved this problem, but I couldn't find anything else via Google. I had the same problem with using read in ZETI (Zebra RFD8500). The Zebra tech support told me that to use access operations like read and write, you have to turn off dynamic power (which I think is on by default).
Unfortunately, I am not using the iOS API/SDK (writing a custom one for another device), but here's the gist of what you'd be doing:
Turn off dynamic power
Do an inventory
Read some memory bank, like the EPC bank. Optionally, you can also specify access criteria to single out a tag.
To test how this worked in ZETI, I screened into the RFD8500 (on my Mac, doing ls /dev/tty.RFD* lists several ttys, I chose the one ending in "-R"):
screen /dev/tty.RFD8500{long number}-R
Then I issued these commands:
dp .disable
in
rd
Commands:
dp = setdynamicpower
in = inventory
rd = read
After issuing "rd", you should be able to see the user memory banks (the default bank for the "rd" command).

How to create TI-BASIC (TI-84+) input forms?

In the TI-BASIC programming language (Specifically TI-84+), how do you create input forms, such as the ones included in the default apps on the TI-84+.
The image included here shows an example of what I'm trying to create: A menu that you can scroll through and input multiple variables freely before executing a function
Additionally, is it possible to make this menu dynamically-updating as variables are entered?
You've set a rather tall order for TI-Basic to fill. user3932000 is correct; there is no built in function to create an input form of the type you request.
However, there is nothing stopping you from creating an interactive interface yourself. Creating it from scratch will be a time consuming and, it will consume a significant amount of memory on your calculator. There is no boilerplate code you plug your variables into to get the results you want, but you might have some luck modeling it after this quadratic solver I wrote.
ClrHome
a+bi
Output(1,1," QUADRATIC
Output(2,1," AX²+BX+C
Output(3,1,"ZEROS:
Output(6,1,"A=
Output(7,1,"B=
Output(8,1,"C=
DelVar YDelVar D
" →Str1
While Y≠105
getKey→Y
If Ans
Then
Output(X,4,Str1
Output(3,7,Str1+Str1+Str1+"
End
X+(Ans=34)-(Ans=25
If Ans<6:8
If Ans>8:6
Ans→X
Output(Ans,16,"◄
D(Y≠45→D
If Y=25 or Y=34
sum({A,B,C}(X={6,7,8→D
If Y=104:⁻D→D
10not(Y)+Y(102≠Y)-13int(Y/13(2>abs(5-abs(5-abs(Y-83
If Ans≤9
D10+Ans-2Ans(D<0→D
If X=6:D→A
If X=7:D→B
If X=8:D→C
If A
Then
2ˉ¹Aˉ¹(⁻B+{1,⁻1}√(B²-4AC
Else
If B
Then
⁻C/B
Else
If C
Then
"No Zeros
Else
"All Numbers
End
End
End
Output(3,7,Ans
Output(6,3,A
Output(7,3,B
Output(8,3,C
End
ClrHome
Ans
Here's a GIF of what it does for you.
With a little more work. This code could be used on the Graph screen instead of the home screen, giving more option in terms of layout and design.
In the TI-BASIC programming language (Specifically TI-84+), how do you create input forms, such as the ones included in the default apps on the TI-84+.
There are many ways to ask for input in your program:
Prompt: Asks for input and stores it in a variable. For example, Prompt A. Simplest way to ask for input, but not very visually appealing.
Input: Similar to the Prompt command, except that now you can include text within the input. For example, Input "What is your name?",A.
Menu(: Multiple choice input, and each choice is connected to a Lbl marker somewhere else in the script. Much like the error screen with the quit/goto choices that you've probably seen. For example, Menu("Are you a boy or a girl?","Boy",B,"Girl",G).
getKey: Checks if a certain key is pressed, and will output True (1) if that key is pressed. For example, getKey 105. See here for which numbers each key corresponds to.
The image included here shows an example of what I'm trying to create: A menu that you can scroll through and input multiple variables freely before executing a function http://imgur.com/ulthDRV
I'm afraid that's not possible in programs. You can either put in multiple inputs, or you might be interested in looking into making apps instead.
Additionally, is it possible to make this menu dynamically-updating as variables are entered?
If you're talking about the text on top of the screenshot, yes you can; just put a Disp command or something after each line of Input, so that it continuously overwrites the text above with new text after you input a variable.

X3270 Connection and Programming

I'm looking at using a X3270 terminal emulator. I have http://x3270.bgp.nu/ looked over this source material and still don't see how to start using the tool or configure it.
I'm wonder how I can open a terminal and connect. Another question is how could I integrate this into a python program?
edit:
here is a snippet:
em = Emulator()
em.connect(ip)
em.send_string('*user name*')
em.exec_command('Tab')
em.send_string('*user password*')
em.send_enter()
em.send_enter()
em.wait_for_field()
em.save_screen("{0}screenshot".format(*path*))
looking at the save screen i see that the cursor hasn't moved? I can move the cursor using
em.move_to(7,53)
but after that i don't get any text sent through. Any Ideas?
Here's what I do; it works 100% of the time:
from py3270 import *
import sys, os
host = "%s" % sys.argv[1].upper()
try:
e = Emulator()
e.connect(host)
e.wait_for_field()
except WaitError:
print "py3270.connect(%s) failed" % (host)
sys.exit(1)
print "--- connection made to %s ---" % (host)`
If you haven't got a network connection to your host, that wait_for_field() call is going to wait for a full 120 seconds. No matter what I do, I don't seem to be able to affect the length of that timeout.
But your user doesn't have to wait that long, just have him kill your script with a KeyboardInterrupt. Hopefully, your user will grow accustomed to success equaling the display of that "--- connection made ..." message so he'll know he's in trouble when/if the host doesn't respond.
And that's a point I need to make: you don't connect to a terminal (as you described), rather you connect to a host. That host can be either a VTAM connection or some kind of LPAR, usually TSO or z/VM, sometimes CICS or IMS, that VTAM will take you to. Each kind of host has differing prompts & screen content you might need to test for, and sometimes those contents are different depending on whose system you're trying to connect to. Your script becomes the "terminal", depending on what you want to show your user.
What you need to do next depends on what kind of system you're trying to talk to. Through VTAM? (Need to select a VTAM application first?) To z/VM? TSO? Are you logging on or DIALing? What's the next keystroke/field you have to use when you're working with a graphic x3270/c3270 terminal? You need to know that in order to choose your next command.
Good luck!
Please read my comment above first - it would be helpful to have more detail as to what you need to do.
After considering that…have you looked at the py3270 package at https://pypi.python.org/pypi/py3270/0.1.5 ? The summary says it talks to x3270.

TCL (thermal control language) [printer protocol] references

I'm working on supporting of the TCL (thermal control protocol, stupid name, its a printer protocol of futurelogic) but i cannot find resources about this protocol, how it is, how it works, nothing, on theirs site i only found this mention http://www.futurelogic-inc.com/trademarks.aspx
any one had worked with it? does any one knows where can i find the data sheet?
The protocol is documented on their website http://www.futurelogic-inc.com/support/downloads/
If you are targetting the PSA66ST model it supports a number of protocols TCL, which is quite nice for delivering templated tickets and, line printing using the Epson ESC/P protocol.
This is all explained in the protocol document.
Oops, these links are incorrect and only correspond to marketing brochures. You will need to contact Futurelogic for the protocol documents. Probably also need to sign an NDA. Anyway, the information may guide you some more.
From what I can gather, it seems the FutureLogic thermal printers do not support general printing, but only printing using predefined templates stored in the printer's firmware. The basic command structure is a caret ^ followed by a one or two character command code, with arguments delimited using a pipe |, and the command ended with another caret ^. I've been able to reverse-engineer a few commands:
^S^ - Printer status
^Se^ - Extended printer status
^C|x|^ - Clear. Known arguments:
a - all
j - jam
^P|x|y0|...|yn|^ - Print fields y0 through yn using template x.
Data areas are defined in the firmware using a similar command format, command ^D|x|y0|...|yn|^, and templates are defined from data areas using command ^T|z|x0|...|xn|^.

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