stdio.h
20 May 2011 23:41 #9959
by BigJohnT
Replied by BigJohnT on topic Re:stdio.h
Comp is a bit limited and designed for simple components. If you needs are special write it in C then compile.
John
John
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23 May 2011 15:22 #9995
by meisu
Replied by meisu on topic Re:stdio.h
That's what I was doing, but I was trying to compile with the comp compiler. Should I use a different compiler?
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23 May 2011 16:20 #9996
by psha
Replied by psha on topic Re:stdio.h
If you want realtime component you are not allowed to use stdio.h and everything else from libc.
Realtime components are executed in kernel space and thus it's not possible to link with arbitrary userspace libraries
Realtime components are executed in kernel space and thus it's not possible to link with arbitrary userspace libraries
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23 May 2011 16:21 #9997
by andypugh
Replied by andypugh on topic Re:stdio.h
You can use a #include statement in the code after the ;; and many of the sample files in the docs do this:
linuxcnc.org/docs/html/hal_comp.html
Alternatively, if you need the #include statement to be earlier in the generated C-code, you can use the undocumented "include" keyword before the ;; in the .comp file.
linuxcnc.org/docs/html/hal_comp.html
Alternatively, if you need the #include statement to be earlier in the generated C-code, you can use the undocumented "include" keyword before the ;; in the .comp file.
component random_example "this component includes libraries"
pin bit in random_pin
include <stdio.h>
;;
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23 May 2011 16:36 #9998
by andypugh
Replied by andypugh on topic Re:stdio.h
psha wrote:
Good point. He probably needs to use rtapi_print
www.linuxcnc.org/docview/html/man/man3/rtapi_print.3rtapi.html
If you want realtime component you are not allowed to use stdio.h and everything else from libc.
Realtime components are executed in kernel space and thus it's not possible to link with arbitrary userspace libraries
Good point. He probably needs to use rtapi_print
www.linuxcnc.org/docview/html/man/man3/rtapi_print.3rtapi.html
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24 May 2011 08:37 - 24 May 2011 08:38 #10021
by ArcEye
Replied by ArcEye on topic Re:stdio.h
Hi
When writing a realtime module it is however surprising what is still available, sometimes in different headers than you might be used to.
I am writing a serial comms module at present and I trawled through to see if it was possible to write as a real time module.
It of course isn't, unless you wanted to re-write half of the C library and address raw devices, it is after all a kernel module.
It was interesting to find the functionality that was available however. Comp searches the /usr/src/linux-headers-2.6.32-122-rtai/include directory on my setup by default, so putting #include<linux/termios.h> for example will work.
It is worth considering writing a user-space module, unless your application is extremely time critical.
I was surprised at how often polling occurred and found this route more than sufficient to check for the next byte on a serial stream and respond to it.
With of course the big advantage of having stdlib.h stdio.h string.h etc etc. available to address everything at an abstracted higher level.
good luck
When writing a realtime module it is however surprising what is still available, sometimes in different headers than you might be used to.
I am writing a serial comms module at present and I trawled through to see if it was possible to write as a real time module.
It of course isn't, unless you wanted to re-write half of the C library and address raw devices, it is after all a kernel module.
It was interesting to find the functionality that was available however. Comp searches the /usr/src/linux-headers-2.6.32-122-rtai/include directory on my setup by default, so putting #include<linux/termios.h> for example will work.
It is worth considering writing a user-space module, unless your application is extremely time critical.
I was surprised at how often polling occurred and found this route more than sufficient to check for the next byte on a serial stream and respond to it.
With of course the big advantage of having stdlib.h stdio.h string.h etc etc. available to address everything at an abstracted higher level.
good luck
Last edit: 24 May 2011 08:38 by ArcEye.
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