POSIX message queues

I want to create am message queue using POSIX mq_open(), unfortunately no message queue is created and mq_open() only returns -1.

Any ideas how i could get more information why mq_open() failed or how i could debug it further?


#include <mqueue.h>
...
#define MAX_MSG   100
#define OVER      (-1)
#define PMODE     0666
#define QUEUENAME "/myipc"
#define QUEUESIZE 10
...
mqd_t id;
struct mq_attr attr;
attr.mq_maxmsg = QUEUESIZE;
attr.mq_msgsize = sizeof (int);
attr.mq_flags = 0;

id = mq_open (QUEUENAME, O_RDWR, PMODE, &attr);

USE WINDOWS!

Yeah, Windows is way better. I tried Debian, but I can't get the DVD drive to work (after about five hours of trying). Stick with Windows if you don't want to spend more time configuring your system than actually using it.

>>2
>>3
/g/ is that way, seriously -->

>>4
If I wanted help, I'd ask /g/.

>>5
If I wanted my anus haxed, I'd ask /prog/.

USE MAC OS!

>>3
You can use both at the same time. It's called Ubanto.

>>8
Debian is Ubanto.

>>1
The mq_open() function is marked as part of the Message Passing option.
It's optional. It may be that your system does not support it.

>>10
http://www.opengroup.org/onlinepubs/000095399/functions/mq_open.html
P.S. Look at errno and the ERRORS section of that page, and you'll find out why it fails.

Short answer -

#include <errno>
#include <string.h>
#include <stdio.h>

fprintf( stderr, "Reason it is fucking up: %s\n", strerror( errno ) );

┌────────────────────────────────────────────────┒
│ ◕                   REASON                   ◕ ┃
│                  Version 1.0B7                 ┃
│ Gatling type 3 mm hypervelocity railgun system ┃
│            Ng Security Industries, Inc.        ┃
│        PRERELEASE VERSION-NOT FOR FIELD USE    ┃
│          DO NOT TEST IN A POPULATED AREA       ┃
│ ◕             -ULTIMA RATIO REGUM-           ◕ ┃
┕━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┛

◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕◕

>>14
How depressing.

>>13
Everyone listens to Reason.

    ┌────────────────────────────────────────────────┒
    │ ◕                   REASON                   ◕ ┃
    │                  Version 1.0B7                 ┃
    │ Gatling type 3 mm hypervelocity railgun system ┃
    │            Ng Security Industries, Inc.        ┃
    │        PRERELEASE VERSION-NOT FOR FIELD USE    ┃
    │          DO NOT TEST IN A POPULATED AREA       ┃
    │ ◕             -ULTIMA RATIO REGUM-           ◕ ┃
    ┕━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┛
    ┌────────────────────────────────────────────────┒
    │ ◕                   REASON                   ◕ ┃
    │                  Version 1.0B7                 ┃
    │ Gatling type 3 mm hypervelocity railgun system ┃
    │            Ng Security Industries, Inc.        ┃
    │        PRERELEASE VERSION-NOT FOR FIELD USE    ┃
    │          DO NOT TEST IN A POPULATED AREA       ┃
    │ ◕             -ULTIMA RATIO REGUM-           ◕ ┃
    ┕━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┛
    ┌────────────────────────────────────────────────┒
    │ ◕                   REASON                   ◕ ┃
    │                  Version 1.0B7                 ┃
    │ Gatling type 3 mm hypervelocity railgun system ┃
    │            Ng Security Industries, Inc.        ┃
    │        PRERELEASE VERSION-NOT FOR FIELD USE    ┃
    │          DO NOT TEST IN A POPULATED AREA       ┃
    │ ◕             -ULTIMA RATIO REGUM-           ◕ ┃
    ┕━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┛

┌────────────────────────────────────────────────┒
│ ◕                   REASON                   ◕ ┃
│                  Version 1.0B7                 ┃
│ Gatling type 3 mm hypervelocity railgun system ┃
│            Ng Security Industries, Inc.        ┃
│        PRERELEASE VERSION-NOT FOR FIELD USE    ┃
│          DO NOT TEST IN A POPULATED AREA       ┃
│ ◕             -ULTIMA RATIO REGUM-           ◕ ┃
┕━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┛

┌────────────────────────────────────────────────┒
│ ◕                   REASON                   ◕ ┃
│                  Version 1.0B7                 ┃
│ Gatling type 3 mm hypervelocity railgun system ┃
│            Ng Security Industries, Inc.        ┃
│        PRERELEASE VERSION-NOT FOR FIELD USE    ┃
│          DO NOT TEST IN A POPULATED AREA       ┃
│ ◕             -ULTIMA RATIO REGUM-           ◕ ┃
┕━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┛

>>17,18
WHAT ARE YOU DOING

>>11
>>12
OP here, Thank you, i found out it was a permissions problem with /dev/mqueue/. Now fixed.

∵∴∵∴∵∴∵∴∵∴∵∴∵∴∵∴∵∴∵∴∵∴∵∴∵∴∵∴∵∴∵∴─────────────────────────┒
    │ ◕          ∵∴∵∴∵∴∵∴  ∵∴EASON    ∵∴∵∴     ∵∴∵∴ ◕ ┃
∵∴∵∴∵∴∵∴∵∴∵∴∵∴    ∵∴∵∴Do∵'t∵∴hi∵k.∵e∵l∵∴nd∵∴∵∴∵∴∵∴∵∴∵∴   ┃sinn
    │ Ga∵∴∵∴∵∴∵∴∵∴∵∴∵∴∵∴∵∴∵∴∵∴∵∴∵∴∵∴∵∴∵∴city rail∵∴∵∴∵∴∵∴em ┃
    │            Ng Secur∵∴∵∴∵∴∵∴∵∴stries, Inc.        ┃
∵∴∵∴∵∴∵∴ PRERELEASE∵∴∵∴ION-NOT ∵∴LD ∵∴∵∴∵∴∵∴USE    ┃
    │     ∵∴∵∴∵∴∵∴ TEST IN A PO∵∴∵∴∵∴∵∴∵∴TED AREA       ┃
    │ ◕       ∴∵∴∵∴∵∴∵∴∵∴∵MA R∵∴∵∴∵∴∵∴M-     ∵∴∵∴∵∴∵∴ ◕ ┃
∴∵∴∵∴∵∴∵∴∵∴∵∴∵∴∵∴∵∴∵∴∵∴∵∴∵∴∵∴∵∴∵∴∵∴∵━━━━━━━━━━━━━━━━━━━━━━━━━━━━┛

>>13,16-19,22
Is that in any way relevant to the topic, or is it a way of saying ``I've read Snow Crash''?

errno

>>23
I haven't read it.
I bought it because you recommended it to me here, but I just can't read this bullshit.

Snow Crash and Neuromancer are currently being used to prop up my monitor.  Hence, I cannot read them.

>>25
Why is that?

>>27
It wants to be a novel about hackers, but it is not. 256 ports located evenly at 256 km intervals? No thanks.

>>28
That's why I just read it as a regular book. Same thing as with Uplink.

>>28
You don't understand Snowcrash and/or early cyberpunk culture. Please refrain from making stupid uneducated comments. Thanks.

>>30
So I don't like something and just because I don't know cyberpunk, my opinion is invalid? HURRR.

>>31 has never discussed books, movies or music with anybody.

>>32
I have. I have also trolled you, note the HURRR. I am also not >>28.

>>33
Tsk, tsk. You're only trolling yourself (constantly, I might add), and I wish you would see that.

>>31
An assertion such as

It wants to be a novel about hackers

Is not an opinion, and as such is open for valid critical attack. Additionally, you don't understand Trolling and/or /prog/ culture. Please refrain from making stupid uneducated comments. Thanks.

>>35
get the fuck out

>>35
Please stay in /prog/, we love you.

>>1
Message queues?  USE FUCKING ERLANG!  Quit dicking around with forcing shit you know to try to do something it sucks at!  Learn something else for once!

Yeah, OP. Please use Erlang. Otherwise it will remain a useless toy language forever, confined to some obscure telephony equipment, and >>38's penis will never be huge.

>>1
Message queues?  USE FUCKING HASKELL!  Quit dicking around with forcing shit you know to try to do something it sucks at!  Learn something else for once!

It's like the film Hackers. When I first saw it, as an arrogant teenager, I mocked its unrealistic portrayal of hacking and computers. But viewing it later on, as a more mature adult, I  appreciated it as an artistic, conceptual construction that referenced hacker culture in the same way that all good art holds a mirror up to society. Also, the chick was hot.

>>41
Absolute twaddle. The movie hackers is pure fiction as hacking was never like that.

>>42 was never a real hacker and never will be, thus doesn't know what it's like.

>>42
... but it will be!  3D visualizations in tools FTW!

>>41
roflwafflebbq
I am constantly haxing my anus and thus I am a real haxer. I have haxed 1002 ports with 32 selfwritten selfextracting executables that overwrite explorer.exe and recompile the linuxkernel. GTFO, failure.

>>44
Yeah, yeah. Enlightenment will do that. You just have to wait 2D to be stable, then you might have 3D. With a complete redesign of everything.

>>42
I know. That's the point.

>>46
I'm holding out for DR18, due sometime in the next universe after the Big Crunch cycle.

Lain.