simple_strtoull(9)

📦 version 7.3.1, in nixpkgs unstable

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

okay so real talk, this one lives in the Kernel API Manual and her whole job is converting a string to an unsigned long long. that's it, that's the gig. 🎀

✨ NAME ✨

simple_strtoull — convert a string to an unsigned long long 🦋

like literally. string goes in, big unsigned number comes out. no cap.

🌸 SYNOPSIS 🌸

unsigned long long simple_strtoull (const char *cp , char **endp ,
       unsigned int base );

bestie look at this signature. she takes three things and gives you back an unsigned long long. so generous of her honestly 👑

🫶 ARGUMENTS 🫶

  • cp — the start of the string 💖 like, the actual string you're tryna parse, point her at the beginning of it
  • endp — a pointer to the end of the parsed string will be placed here ✨ so she can tell you where she stopped reading. very thoughtful. very main character.
  • base — the number base to use 🔥 base 10, base 16, whatever vibe you're on

👑 DESCRIPTION 👑

okay so this is the part where i have to be honest with you 🫶

This function has caveats. Please use kstrtoull instead.

that's it. that's the whole description. not me reading that and immediately side-eyeing her 💀 she's got caveats, bestie. caveats. the manpage doesn't even elaborate, it just says "please use kstrtoull instead" and moves on. so like… take the hint. kstrtoull is the one. simple_strtoull is the friend you love but who has caveats. 😭

🌈 SEE ALSO 🌈

the whole extended friend group, gathered in Kernel file ./lib/vsprintf.c 🧚:

every single one of them. i listed all thirteen because i'm not a flake 💅

fr fr though: if you're reaching for simple_strtoull and you read that description and went "eh, it's fine" — that's the caveat talking. she told you herself. use kstrtoull. 🫶

mwah 💋 this page came from ./lib, dated October 2026, and it's simple_strtoull(9) — and yes she signed off with the same name she opened with, iconique behavior, she's consistent, we love that for her 💜✨

📦 where this page comes from