UIDINFO(9)

💖 UIDINFO(9) 💖

ok so this is the Kernel Developer's Manual page for uidinfo, uihashinit, uifind, uihold, and uifree — aka the functions for managing UID information. bestie, this is kernel-land, so hydrate before reading 🫶

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✨ NAME ✨

uidinfo, uihashinit, uifind, uihold, uifree — functions for managing UID information 💅

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🌸 SYNOPSIS 🌸

#include <sys/param.h>
#include <sys/proc.h>
#include <sys/resourcevar.h>

void
uihashinit(void);

struct uidinfo *
uifind(uid_t uid);

void
uihold(struct uidinfo *uip);

void
uifree(struct uidinfo *uip);

literally just include the three headers and you're in 🎀

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🦋 DESCRIPTION 🦋

The uidinfo family of functions is used to manage uidinfo structures. and when I say each uidinfo structure maintains per uid resource consumption counts — I mean it, no cap: that includes the process count and the socket buffer space usage. lowkey iconic bookkeeping 🔥

• uihashinit() — initializes the uidinfo hash table and its mutex. that's the whole job. and heads up: this function should only be called during system initialization. not a "whenever you feel like it" situation 🙈
• uifind() — looks up and returns the uidinfo structure for uid. if no uidinfo structure exists for uid, a brand new structure will be allocated and initialized for you. the uidinfo hash mutex is acquired and released. slay, it's giving concierge service 👑
• uihold() — increases the reference count on uip. uip's lock is acquired and released. keep that thing alive, bestie 💖
• uifree() — decreases the reference count on uip, and if the count reaches 0 then uip is freed. uip's lock is acquired and released, and the uidinfo hash mutex may be acquired and released. bye diva, you had a good run 🦋

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⭐ RETURN VALUES ⭐

uifind() returns a pointer to an initialized uidinfo structure, and it should not fail. that's it. that's the whole return section. she's reliable like that 😌

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👑 AUTHORS 👑

This manual page was written by Chad David <davidc@acns.ab.ca>. thank you Chad, king behavior 🫶

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that's the whole page!! go forth and manage your UID info, main character ✨

written for the Debian project, dated July 10, 2001 — yeah she's vintage, and she still ate 💅