Segmentation fault problem in Embedded system

[Shreehari]

Hello

I had written a code to read the digital output of my embedded system.and compiled i through the GDB.and executed in target system.But it gives Segmentation fault error.My program is simple and is written below...


the value is a file located in do5 file.
-----------------------------------------------------------------------------------------
#include<stdio.h>

main()
{

FILE *file =fopen("/sys/class/sbc2800/d05/value","wt");
fprintf(file,"1");
fclose(file);

}
----------------------------------------------------------------------------------------

Pls rply ..I am using ARM 9 processor.and logged as root. and also please tell me how to generate the executable in tiny model(like compact,small,medium,tiny).


Regards

 

[amraldo]

What is the

"wt"

in the fopen API?
--
Amr

 

[Shreehari]

wt means write in text mode.

 

[amraldo]

I checked the fopen API @ https://www.opengroup.org/onlinepubs/009695399/functions/fopen.html. I do not see the "t". Anyway, can you debug till you find the line when executed gives the segmentation fault?
--
Amr

 

[Shreehari]

But several documents says supports "t" mode.I had seen some documents in internet.Your link doesn't work.
Also the Embedded system manual also tells the same.

 

[amraldo]

Try this link https://www.opengroup.org/onlinepubs/009695399/functions/fopen.html
It is working with me. If it did not, just google opengroup fopen.
--
Amr

 

[Shreehari]

ok I will work with simple "w" mode and let me tell you the result.

Added after 3 hours 33 minutes:

I had written 'w' inplace of 'wt ',but still segmentation fault comes...

 

[amraldo]

Try to know which line gives the segmentation fault, in order to remove the error.
Add some printf or use a debugger.
--
Amr

 

[kennedy123]

Do not assume that the file was successfully opened. If fp is NULL, you will get segmentation fault. You need something like:

FILE *file =fopen("/sys/class/sbc2800/d05/value","wt");
if(file) fprintf(file,"1");
if(file) fclose(file);

Try this. Does it still give segmentation fault or does it complete ?

Kennedy