is a data communications endpoint for exchanging data between processes executing within the same host operating system.

learn more… | top users | synonyms

29
votes
6answers
7k views

Who's got the other end of this unix socketpair?

I want to determine which process has the other end of a UNIX socket. Specifically, I'm asking about one that was created with socketpair(), though the problem is the same for any UNIX socket. I ...
21
votes
2answers
10k views

/proc/PID/fd/X link number

In Linux, in /proc/PID/fd/X, the links for file descriptors that are pipes or sockets have a number, like: l-wx------ 1 user user 64 Mar 24 00:05 1 -> pipe:[6839] l-wx------ 1 user user 64 Mar 24 ...
19
votes
5answers
5k views

What is a socket?

Could someone explain to me what a socket is? I see it in many acronyms in context of SSL, etc. Also, why is it called a socket? Is it purely because it was what a name they invented? Or was it the ...
5
votes
2answers
10k views

rpc.statd running on system not using NFS

I have a Debian machine that gets warnings (via the Tiger automatic auditor) that rcp.statd is listening on such-and-such socket. Googling shows rpc.statd is a daemon used by NFS. As far as I know, ...
19
votes
4answers
1k views

Are Unix Internet sockets files?

I understand that "Everything is a file" is one of the major concepts of Unix, but sockets use different APIs that are provided by the kernel (like socket, sendto, recv, etc.), not like normal file ...
11
votes
4answers
8k views

Are FIFO, pipe & Unix domain socket the same thing in Linux kernel?

I heard that FIFOs are named pipes. And they have exactly the same semantics. On the other hand, I think Unix domain socket is quite similar to pipe (although I've never made use of it). So I wonder ...
4
votes
1answer
128 views

Does traffic addressed to one of a Linux system's own interfaces ever leave the system?

I have two separate servers running on the same port on a Linux system, one binded to the loopback interface, and the other to the public Ethernet interface. If I connect a client on that system to ...
2
votes
1answer
260 views

Connect through different interfaces to the same server (SO_BINDTODEVICE): Destination Host Unreachable

I have 2 interfaces: eth0 and wlan0, each one connected to a different router. Their network specs are these: eth0: ip: 192.168.1.7 Gateway: 192.168.1.1 Submask: 255.255.255.0 wlan0: ...
3
votes
2answers
64 views

Distinguish TCP server from client within netstat output

I have a socket connection between a client process and a server process, both running on my machine. There are two entries shown for the connection as, sudo netstat -ntp | grep 56442 tcp 1 ...
2
votes
1answer
2k views

Why can't I use strace with rsh?

If I run rsh, it works, but prints some strange “Connection refused” messages at the beginning: $ rsh localhost pwd connect to address 127.0.0.1 port 544: Connection refused Trying krb4 rsh... ...
1
vote
2answers
227 views

How to see the amount of pending data on a unix domain socket?

When I'm logged to a tmux session from two different computers, I'd like to be able to trace the amount of pending data on the sockets of both tmux session. To test this I logged to computer A and to ...
1
vote
1answer
1k views

Where to locate “sockets”

I am new to this, so sorry if its obvious. I am running a Debian server and installing the likes of UWSGI, NGinx etc on there. The configurations keep talking about pointing to "sockets". In the ...