# le\_atClient\_Start(fd) crashes an app

**URL:** <https://forum.legato.io/t/le-atclient-start-fd-crashes-an-app/3117>\
**Category:** Legato Application Framework\
**Created:** [March 2, 2018, 5:10am UTC](https://forum.legato.io/t/le-atclient-start-fd-crashes-an-app/3117 "2018-03-02T05:10:12Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![EvetsMostel](https://avatars.discourse-cdn.com/v4/letter/e/3ab097/32.png) [@EvetsMostel](https://forum.legato.io/u/EvetsMostel)\
**Post date:** [March 2, 2018, 5:10am UTC](https://forum.legato.io/t/le-atclient-start-fd-crashes-an-app/3117/1 "2018-03-02T05:10:12Z")

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I have a WP7601 module, Running Legato 7.11. I’m trying to get the at commands to work, but right after the open, when I call le\_atClient\_Start(fd), the avcDaemon starts complaining with lots of LE\_NOT\_FOUND, failed to open /avc/fw/updateState… etc And then the app crashes. The code I’m using is straight out of the test for 7.11 framework. If I run JUST that code, I can get a little further where it tries to call le\_atClient\_Stop() and it crashes there. Has anyone even got this to work on a WP7601?

Thanks,  
Evets

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**Author:** ![pinkesh](https://sea1.discourse-cdn.com/flex019/user_avatar/forum.legato.io/pinkesh/32/221_2.png) [@pinkesh](https://forum.legato.io/u/pinkesh)\
**Post date:** [March 2, 2018, 10:13am UTC](https://forum.legato.io/t/le-atclient-start-fd-crashes-an-app/3117/2 "2018-03-02T10:13:05Z")

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Hello,

What is the device name pointing to fd ?  
can you share the sample code flow of your app ?

Thanks,  
Pinkesh Shah

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<div class="post-metadata">

**Author:** ![EvetsMostel](https://avatars.discourse-cdn.com/v4/letter/e/3ab097/32.png) [@EvetsMostel](https://forum.legato.io/u/EvetsMostel)\
**Post date:** [March 2, 2018, 2:40pm UTC](https://forum.legato.io/t/le-atclient-start-fd-crashes-an-app/3117/3 "2018-03-02T14:40:53Z")

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Hi @pinkesh,  
Like I said above, this code is straight out of the Test code for the atClient. See below:  
//! [DeviceBinding]  
//! [binding]  
int fd = open(“/dev/ttyAT”, O\_RDWR | O\_NOCTTY | O\_NONBLOCK);

```
LE_ASSERT(fd >= 0);

int newFd = dup(fd);

DevRef = le_atClient_Start(fd); // << In my app, it crashes here. Keep in mind that 

```

// my app has a lot of other bindings, whereas the test app, it only has le\_atClient.  
//! [binding]

```
// Try to stop the device
LE_ASSERT(le_atClient_Stop(DevRef) == LE_OK); // <<- In the test app it crashes here.
LE_ASSERT(le_atClient_Stop(DevRef) == LE_FAULT);

```

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<div class="post-metadata">

**Author:** ![EvetsMostel](https://avatars.discourse-cdn.com/v4/letter/e/3ab097/32.png) [@EvetsMostel](https://forum.legato.io/u/EvetsMostel)\
**Post date:** [March 15, 2018, 3:38am UTC](https://forum.legato.io/t/le-atclient-start-fd-crashes-an-app/3117/4 "2018-03-15T03:38:51Z")

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Has anyone run this on the WP7601 product? I’ve tried with the MangOH board (green) and our own product and I still get the same issue.

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**Author:** ![muralinagraj](https://avatars.discourse-cdn.com/v4/letter/m/45deac/32.png) [@muralinagraj](https://forum.legato.io/u/muralinagraj)\
**Post date:** [October 12, 2018, 12:21pm UTC](https://forum.legato.io/t/le-atclient-start-fd-crashes-an-app/3117/5 "2018-10-12T12:21:35Z")

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Hi @EvetsMostel,  
Yes, Even we see atClientTest App stops failing to open /avc/fw/updateState avcDaemon and avcDaemon complaining with lots of LE\_NOT\_FOUND using **legato-17.11.0(Release 7.0.1)** and also with **legato-18.01.0 version(Release 8)**.

Please check with the legato-18.03.0 version(WP7xx Release 9 ), This issue has been resolved in **legato-18.03.0** version.

Regards,  
Muralidhara N.