ipc(2)

💖 ipc(2) — System Calls Manual energy ✨

okay bestie, pull up a chair, we're talking about ipc(2) — the System V IPC system calls, straight out of the System Calls Manual. yes the whole manual. she's iconic, she's lowkey ancient, and she's the backstage pass to how messages, semaphores and shared memory actually get summoned in the kernel. let's go 🫶

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🌸 NAME 🌸

ipc — System V IPC system calls 💅

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🎀 LIBRARY 🎀

Standard C library (libc, -lc)

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✨ SYNOPSIS ✨

#include <linux/ipc.h>        /* Definition of needed constants */
#include <sys/syscall.h>      /* Definition of SYS_* constants */
#include <unistd.h>

int syscall(SYS_ipc, unsigned int call, int first,
            unsigned long second, unsigned long third, void *ptr,
            long fifth);

Note: glibc provides no wrapper for ipc(), bestie, so you're forced to go through syscall(2). there is no shortcut. no vibes-only path. it's giving "do it yourself" 😭

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💜 DESCRIPTION 💜

ipc() is the common kernel entry point for all the System V IPC calls — that's messages, semaphores, and shared memory, all three girlies sharing one door 🚪✨

call is the thing that decides which IPC function gets invoked. everything else you hand over just gets passed straight through to whatever call you picked. no extra processing, no side quests, just vibes and forwarding 🦋

now here's the real tea: user-space programs should be calling the appropriate functions by their usual names. like, the normal ones. the ones with actual wrappers. ipc() is not your main character — she's the plumbing. only standard library implementors and kernel hackers need to know about ipc() at all. so if that's not you, you can literally close this tab 🙈

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🌈 VERSIONS 🌈

on some architectures — for example x86-64 and ARM — there is no ipc() system call at all 💀 instead, msgctl(2), semctl(2), shmctl(2), and so on really are implemented as separate system calls. like, genuinely separate. not a facade. so on those platforms the "one entry point" thing is just… not a thing.

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👑 STANDARDS 👑

Linux. that's it, that's the standard. periodt 💅

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🦋 SEE ALSO 🦋

• msgctl(2)
• msgget(2)
• msgrcv(2)
• msgsnd(2)
• semctl(2)
• semget(2)
• semop(2)
• semtimedop(2)
• shmat(2)
• shmctl(2)
• shmdt(2)
• shmget(2)
• sysvipc(7)

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and that's the whole page, bestie 🎀 this one came to you from Linux man-pages 6.20, dated 2026-02-08 — love her, respect her, she's been carrying the kernel docs on her back fr fr ✨ go call your IPC functions by their normal names and stay hydrated 💖