Thread: Program crashing at fgets() - any ideas why?

Hi all,

As a part of my program, I am opening a file and reading it line by line in a loop and processing the lines.

But my program keep crashing when I try to run it..

Code:

 for(j=0; j< (*anntn)[i].num_peaks; j++)
 	{

           printf("Read line %d\n",j);

           fgets(szbuf, 1500,fp);


 	   sscanf(szbuf,"%f\t%f",&mz_f,&intensity);

           mz_i= (int) (mz_f +0.5);



           if( (*lib_spec)[i][mz_i] < intensity)
  	   {
 	     (*lib_spec)[i][mz_i] = intensity;
  	   }

           printf("Finished read of line %d\n",j);
           printf("%s\n\n",szbuf);
 
 	}
         

        fgets(szbuf, 1500,fp); /** Skipping the blank line after the end of 1 record **/

   }

This is the part of the code which is giving me the problem.. The loop runs exactly 14 times and then crashes. I tried putting the printf statement at different places to see where exactly it crashes. It crashes immediately after calling the fgets function.

When I googled for crashes at fgets(), most of the results talked about crashes because of trying to open a file which was opened before and wasn't closed. I only open this file once. And besides, since the first 14 lines are read correctly, I dont think the problem is because of problems with opening the file.

I thought it could be a problem with the size of szbuf.. But i increased the size 10 times and the program still crashes at the same place.

I am out of ideas. Does any one have any suggestions on what I should try..?

Thanks..

You've not mentioned whether you've been testing the return value for fgets(). If there's a read error it should return a null pointer. I'd probably start off by checking that.