SCANC(9)

💅 SCANC — the kernel dev manual page, bestie edition ✨

okay so real talk: this is scanc from the Kernel Developer's Manual (section 9, obvi — kernel-land 🧚). it's a tiny little function with main character energy, and honestly? she ate. let's get into it 💖

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✨ NAME ✨

scanc — literally just uses a byte string as a lookup table index. that's the whole vibe. no cap 🎀

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🌸 SYNOPSIS 🌸

#include <lib/libkern/libkern.h>

int
scanc(u_int size, const u_char *cp, const u_char table[], int mask);

look at her. iconic signature. four args, one dream 💅

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🦋 DESCRIPTION 🦋

so here's the tea ☕: scanc() scans the byte string cp, and the length of that string is size. simple enough, right?

then — and this is the fun part — a character in the string gets used as an index into the 256-byte table. like, every byte in your string is basically pointing at a lil spot in the table. iykyk 🫶

the scan stops when either of these happens:

• a bitwise-AND of the byte from the table and mask isn't zero 🔥
• or the string is exhausted (you ran out of characters, bestie, it's over 😭)

that's it. that's the whole scan. no notes 👑

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⭐ RETURN VALUES ⭐

scanc() returns the length of the rest of the string — including the character that made the scan stop. yes, she's included, she's part of the count, don't do her dirty 🙈

and if scanc() exhausted the string? it returns 0. zero. nada. the scan found nothing and honestly same 💀

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🎀 HISTORY 🎀

scanc() emulates a VAX instruction with the same name. retro! vintage! a whole ancestor! we respect the lineage 🧚✨

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💖 friendly lil reminder: the details up there are load-bearing — the 256-byte table, the int-typed mask, the "including the stopping character" bit — so don't skip 'em, bestie 🫶

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kisses, this was SCANC(9) from the Debian crew, dated April 24, 2013 — slay forever, periodt 💅✨