C code line, pointer declaration

Dedalus · 06-10-2009, 04:26 AM

Hi

I don't understand this code line:

Code:

struct iphdr *iph=(struct iphdr *)data;

where data is an u_char.
What I can see is that we are creating a pointer (iph) to a iphdr struct, but the right side is not very clear. Can anyone explain the meaning, please?

Thanks in advance

Dedalus

MacGyver · 06-10-2009, 04:32 AM

If this example is too difficult to understand, you should get a good C book and learn the basics. The code is casting data to a struct iphdr * and then assigning it to the newly created variable iph.

BTW, if you mean that data is an unsigned char, then this cast is rather horrible to do and makes little sense to me. In fact, this could be the cause of some ugly problems.

Oh, and welcome to cboard.

Dedalus · 06-10-2009, 04:34 AM

Thanks MacGyver

06-10-2009, 04:26 AM	#1
Dedalus Registered User Join Date: Jun 2009 Posts: 31	C code line, pointer declaration Hi I don't understand this code line: Code: struct iphdr iph=(struct iphdr )data; where data is an u_char. What I can see is that we are creating a pointer (iph) to a iphdr struct, but the right side is not very clear. Can anyone explain the meaning, please? Thanks in advance Dedalus
Dedalus is offline

06-10-2009, 04:32 AM	#2
MacGyver Deathray Engineer Join Date: Mar 2007 Posts: 3,211	If this example is too difficult to understand, you should get a good C book and learn the basics. The code is casting data to a struct iphdr * and then assigning it to the newly created variable iph. BTW, if you mean that data is an unsigned char, then this cast is rather horrible to do and makes little sense to me. In fact, this could be the cause of some ugly problems. Oh, and welcome to cboard. __________________ Last edited by MacGyver; 06-10-2009 at 04:37 AM. Reason: Messed up spelling of type name.
MacGyver is offline

06-10-2009, 04:34 AM	#3
Dedalus Registered User Join Date: Jun 2009 Posts: 31	Thanks MacGyver
Dedalus is offline

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