Joining two values

[frangac]

Hi Salem and all,

How can I cat two bytes which is read in as char and then converted in hex, for e.g.

If I read the first byte (char) and then covert it to hex (26), read
the next char and convert it to hex (ac). Cat the both should be 26ac , then only
print the decimal value.

Is my logic correct or is there a different way of doing this


Please help
Chris

if(j > 67 && j < 70)
	{
		if(j==68)
		{
			printf(" ");
		}

		sprintf(datum, "%x" , xya[j]);
		xy1=fgetc(in);
		sprintf(datum_1, "%x" , xy1);
		
		// this is where i get stuck
		cat datum datum_1
		sprintf (SCV ,"%d" , result fom cat ); 
		//
		
		printf("%d", datum);
	}

 

[Salem]

That would be

int value = xya[j] * 256 + xy1;
sprintf (SCV ,"%d" , value );

--

 

[frangac]

Hi Salem,

Thanks a lot. Your first byte is xya[j] (char) which you * 256 ..ok and when I get the next byt == fgetc xy1, it is also a char??

Chris

for (j=0; j<record_len; j++)
{
	if(j < 1 )
	{
		printf(" ");
		printf("%c",xya[j]);
	}
	
...........
	if(j > 67 && j < 70)
	{
		if(j==68)
		{
			printf(" ");
		}

		
		xy1=fgetc(in);
		int value = xya[j] * 256 + xy1;
		sprintf (SCV ,"%d" , value );

		printf("%d", SCV);
	}

 

[frangac]

Hi Salem,


The result I get with the above code is "17615506841761550684" which is incorrect. What am I doing wrong

Thanks Again
Chris

 

[Salem]

> sprintf (SCV ,"%d" , value );
> printf("%d", SCV);
You're printing a string (SCV) as a decimal (%d)
Use %s in the printf()


--

 

[frangac]

Hi Salem,

I might be missing your point. When we first read the byte it is in char format "&" and when converted it is 26 and so this applies for the next byte "ac", so I cannot see how you would pass it as an int. Should I not convert it to hex or straight into int then only times it by 256. If soo, how can I do this.

Thanks
Chris

 

[cpjust]

Try something like this:

int num = 0;
...
strcat( datum, datum_1 );
sscanf( datum, "%x", num );