↓. Ryan When I run the app in the IDE it runs perfectly, but after I built it and ran it in the terminal I get a segmentation fault.
Icmp Echo Ping Request
I ran it through gdb and got: Program received signal SIGSEGV, Segmentation fault. IOfgets (buf=0x6032b0 “”, n=6, fp=0x0) at iofgets.c:47 47 iofgets.c: No such file or directory. (gdb) bt #0 IOfgets (buf=0x6032b0 “”, n=6, fp=0x0) at iofgets.c:47 #1 0x4013fa in getconf at cServer.c:119 #2 0x401606 in main at cServer.c:191 I am not so good at understanding the debug output. Cheers, Ryan.
Echo Ping Request
C/C Programming Debug with gdb The procedures to use gdb for debugging a C program. Build with an option -g. Arris tg862g wifi light blinking. gdb. set breakpoints with b. Remember the filename and path is relative to the location where the is located.
interactive commands: n - next s - step p - print c - continue l - list the content of source code context Socket Programming Example 1: Synchronize I/O Operations with Select Select function is somewhat strange, but it's very useful. Take the following situation: you are a server and you want to listen for incoming connections as well as keep reading from the connections you already have. No problem, you say, just an accept and a couple of recvs. Not so fast, buster!
![Request Request](/uploads/1/2/3/9/123954916/888841993.png)
What if you're blocking on an accept call? How are you going to recv data at the same time? 'Use non-blocking sockets!' You don't want to be a CPU hog. Select gives you the power to monitor several sockets at the same time. It'll tell you which ones are ready for reading, which are ready for writing, and which sockets have raised exceptions, if you really want to know that. For example, in a socket program, if you have to send and recv with two different sockets in a same thread process, then it is better to use select instead of non-blocking sockets or polling.
Not only recv or listen can be handled by select with readfds, the writefds could inculde the sending socket (whenever a txbuffer is ready, select will return with this fd). Following example show how to do it a UDPSEND function, hearing a broadcast message as well. Check the example code: Socket Programming Example 2: RAW Socket Doing some raw sockets programming and having some fun.this stuff has some real potential! But having a strange bug in my ping program. The code comes from.
First off I should warn you that I know nothing about sockets so this may not be the answer to your problem, but I did notice that you have some memory related problems that can often lead to strange behaviour. 1) you do not free any of the memory that you malloc. 2) you malloc memory pointed to by ip and ipcmp, then change the value of these pointers to point to some other memory locations. This leaves the previous memory hanging around with no way of using it or freeing it up.
I suspect, given the rest of your code, that you do not need to malloc these two areas in the first place. You also do the same thing with ipreply later in the code. 3) sizeof(packet) will not give you the size of the packet you sent but the size of the pointer to char that packet is. I know that this has nothing to do with the code not working, but it's just a point to notice.
![Ping Ping](/uploads/1/2/3/9/123954916/941384088.png)
All these things may have no effect whatsoever on the curent problem you are seeing, but it is worth fixing them to avoid future problems, but one of them may have some strange side effect that causes your problems. Originally posted by DavT First off I should warn you that I know nothing about sockets so this may not be the answer to your problem, but I did notice that you have some memory related problems that can often lead to strange behaviour. 1) you do not free any of the memory that you malloc.
![Talk Talk](/uploads/1/2/3/9/123954916/897457382.jpg)
2) you malloc memory pointed to by ip and ipcmp, then change the value of these pointers to point to some other memory locations. This leaves the previous memory hanging around with no way of using it or freeing it up. I suspect, given the rest of your code, that you do not need to malloc these two areas in the first place.
Ginger and dj Champain) 09 - Subculture Hero 10 - Bombed (Out Of My Mind) 11 - Robber Of Life 12 - Backstabber 13 - Get Dead 14 - Spotlight The Sun 15 - Powderhead 16 - Hey, I'm Sorry 17 - Ghetto You 18 - Rocker (Feat. Michael Monroe) CD 2 01 - Wireless Mind 02 - Can't Find The Door 03 - Gotta Go 04 - Ghetto You (K.O. CD 1 01 - Look At You 02 - Highlights 03 - U.F.O. Romeo 04 - (Is It) Still Alright To Smile 05 - Eight Balled 06 - Made Me Madman 07 - Let's Go To Hell 08 - Babylon (Feat. Backyard babies diesel and power rar.
You also do the same thing with ipreply later in the code. 3) sizeof(packet) will not give you the size of the packet you sent but the size of the pointer to char that packet is. I know that this has nothing to do with the code not working, but it's just a point to notice. All these things may have no effect whatsoever on the curent problem you are seeing, but it is worth fixing them to avoid future problems, but one of them may have some strange side effect that causes your problems. You are right.i dont need to malloc ip and icmp because of these lines.