socket_connect6(3)

💖 socket_connect6(3) — bestie's guide to making a TCP connection 💖

okay so real talk, this one lives in the Library Functions Manual and it's genuinely one of the most useful little gremlins in libowfat/socket.h. sit with me, we're doing this together 🫶

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✨ NAME ✨

socket_connect6 — attempt to make a TCP connection

like, that's it, that's the whole job. it tries to connect. no cap. 🔥

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🌸 SYNTAX 🌸

#include <libowfat/socket.h>

int socket_connect6(int s, const char ip[16],
                    uint16 port,uint32 scope_id);

four args, one int out, slay 💅

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🦋 DESCRIPTION 🦋

okay so socket_connect6 attempts to make a connection from TCP socket s to TCP port port on IP address ip. that's the whole vibe. simple. iconic.

Now. The meaning of scope_id is dependent on the implementation and the IPv6 IP. On link-local IPv6 addresses it specifies the outgoing interface index. The name (e.g. "eth0") for a given interface index can be queried with getifname. scope_id should normally be set to 0. normally!! don't be extra about it 🙈

socket_connect6 may return

• 0 — to indicate that the connection succeeded (and succeeded immediately, if the socket is non-blocking) ✨
• -1, setting errno to error_inprogress or error_wouldblock, to indicate that the socket is non-blocking 👀
• -1, setting errno to something else, to indicate that the connection failed (and failed immediately, if the socket is non-blocking). 💀

When a background connection succeeds or fails, s becomes writable; you can use socket_connected to see whether the connection succeeded. If the connection failed, socket_connected returns 0, setting errno appropriately.

Once a TCP socket is connected, you can use the read and write system calls to transmit data. yes bestie, that's the payoff, that's the main character moment 👑

You can call socket_connect6 without calling socket_bind6. This has the effect as first calling socket_bind6 with IP address :: and port 0. so it just handles it for you, lowkey thoughtful of it 🎀

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🎀 EXAMPLE 🎀

#include <libowfat/socket.h>

int s;
char ip[16];
uint16 p;

s = socket_tcp6();
socket_bind6(s,ip,p);
socket_connect6(s,ip,p,0);

look at that. clean. no notes. 🌈

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💜 SEE ALSO 💜

• socket_connect4(3)
• socket_fastopen_connect6(3)
• socket_getifname(3)

go read these next, iykyk 📚

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okay bye my love 🫶 this was socket_connect6(3) straight out of the Library Functions Manual, and yeah, that's the same socket_connect6(3) you see at the bottom of the page — periodt. 💖✨🌸🦋