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[doubty]

int main()
{
FILE *file;
file = fopen("C:/Users/dell/Desktop/File/init.txt","r");
int xcount;
char c[4],brown_spec[2],brown_conc[1];
float *x=NULL;
float ***brown;
int line_read=0,xtime=0,xconc_range=0,xspecies=0,i=0,j=0;
if (file!=NULL)
{
		
		while(line_read<3 && fgets(c,10,file)!=NULL )
		{
            line_read++;
			if (line_read==1)
			{
				xtime=atoi(c);
			}
			if (line_read==2)
			{
				xconc_range=atoi(c);
			}
			if (line_read==3)
			{
				xspecies=atoi(c);
			}
		}

		brown=(float***)malloc(xspecies*sizeof *brown);
		for( i=0; i<xspecies ; i++ )
		{
			brown[ i ] =(float**)malloc(xtime* sizeof **brown);/* Allocate 'xtime' number of pointers to int */
			 /*Validate malloc's success/failure using the return value*/
			for( j=0; j<xtime; j++)
			{
				brown[ i ][ j ]= (float*)malloc(xconc_range* sizeof ***brown);/* Allocate 'xconc_range' number of ints */
				/*Validate malloc's success/failure using the return value*/
			}
		}

		while(fgets(c,10,file)!=NULL && line_read>=3)
		{
		  strncpy(brown_spec,&c[2],1);
		 if(brown_spec[0]=='=')
		 {
			 strncpy(brown_spec,&c[1],1);
			 strncpy(brown_conc,&c[3],1);
		 }
		 else
		 {
            strncpy(brown_spec,&c[1],2);
            strncpy(brown_conc,&c[4],1);
		}

		 brown[atoi(brown_spec)][0][atoi(brown_conc)]=1;

		 line_read++;

		}
}  



exit(0);
return 0;

}

Hi The problem with the above code is that if i dont put the exit function before return it gives an error , but when i put the exit function it works fine... can u tell me why such is the case?

Tnks

[MK27]

Hi The problem with the above code is that if i dont put the exit function before return it gives an error , but when i put the exit function it works fine... can u tell me why such is the case?

Not sure exactly why you get an error, but you certainly do not need exit(0) at the end of this code. "return" in main() signifies the end of the program, so anything after an unqualified return statement in main will never happen.

exit() is usually used outside of main to end the program or to trigger atexit() functions.

[tabstop]

What error do you get?

[Zlatko]

It would help to post init.txt so we could try to reproduce the problem.

I would start by removing parts of the program until the error disappeared. You may be getting stack corruption somewhere so that the return address becomes invalid.

[doubty]

Thanks all

[quzah]

 fgets(c,10,file)

Why are you trying to read 10 characters into a buffer of 4 characters?


Quzah.

[Zlatko]

Yes, as quzah pointed out, c is the problem. It needs to be large enough to hold the line, including the newline character and the null terminator. It should be 6 bytes long at least. The fgets line should read:
fgets(c, sizeof(c), file);
assuming that c stays a character array.

[doubty]

Thnks all.. it is wrking fine now...

[nonoob]

Perhaps the problem was, that an early exit(0) prevented any checking of broken addresses and corrupted memory. Still strange though as any necessary clean-up should have caught that.

[Elysia]

That's why it's called undefined behavior.

[WatchTower]

x is assigned value but it's not used.