match_hex(9)

✨ match_hex(9) ✨ — from the Kernel API Manual, bestie 💅

okay so picture this: it's giving "little helper that reads hex out of a string," and honestly? iconic. the function is match_hex, and it lives in section 9 of the Kernel API Manual, which is where all the kernel-functions hang out. 🎀

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🌸 NAME 🌸

match_hex — scan a hex representation of an integer from a substring_t

like, it looks at a chunk of string and goes "hmm yes, that's a hex number, let me get that for you" 🧚

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⭐ SYNOPSIS ⭐

int match_hex (substring_t *s , int *result );

two args, one int coming back at you. no cap. 💜

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🦋 ARGUMENTS 🦋

• s — the substring_t to be scanned, aka the little string-slice main character we're inspecting 🔍
• result — the resulting integer on success, aka where the parsed number gets dropped off 🫶

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💖 DESCRIPTION 💖

Attempts to parse the substring_t s as a hexadecimal integer.

that's it, that's the whole vibe. it takes your substring and tries to read it as hex. slay. ✨

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🔥 RETURN 🔥

On success, it sets result to the integer represented by the string and returns 0. zero means we ate, we devoured, no crumbs. 👑

on failure it returns -EINVAL or -ERANGE. so like, if it's not valid hex you get -EINVAL, and if the number is out of range you get -ERANGE. both of those are the "nope, not today" answers 💀

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🌈 SEE ALSO 🌈

Kernel file ./lib/parser.c — and honestly the whole parser function fam, they all show up together:

match_one(9), match_token(9), match_number(9), match_u64int(9), match_int(9), match_uint(9), match_u64(9), match_octal(9), match_wildcard(9), match_strlcpy(9), match_strdup(9)

one big happy parser family reunion 🎉

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okay that's the whole page, ily, go read some hex 🍓💕

— signed off with love from ./lib, October 2026 edition 💅✨