Stdlib.LargeFile(3)

💖 Stdlib.LargeFile 💖

ok so quick vibe check bestie: this page is from the OCaml library manual, and it's all about Stdlib.LargeFile — the little sub-module that lets you do channel stuff on files that are, like, actually big. no cap.

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✨ NAME ✨

Stdlib.LargeFile — operations on large files. that's it, that's the whole name. slay.

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🎀 Module 🎀

Module Stdlib.LargeFile

like, it's a module. a whole module. main character energy fr.

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🦋 Documentation 🦋

ok so the signature is literally:

Module LargeFile
 : sig end

yes. that's the shape of it. iconic of OCamldoc to show us that.

🌸 the actual tea 🌸

Operations on large files. okay so here's the thing — this sub-module hands you 64-bit variants of the channel functions, specifically the ones that mess with file positions and file sizes. 🫶

the glow-up: instead of representing positions and sizes with regular integers (type int), these alternates use 64-bit integers (type int64). and why do we care? because that's what lets you operate on files whose sizes are greater than max_int. like, the regular int functions simply cannot, they're doing their best, they're not built for that. this is the version that CAN. 💅

lowkey important: if you're staying under max_int, the normal channel functions are fine — these are the "file is too chonky for int" edition. 🔥

👑 the functions 👑

• val seek_out : out_channel -> int64 -> unit — moves the write position on an out_channel to an int64 offset. the 64-bit glow-up of the outgoing seek. ⭐
• val pos_out : out_channel -> int64 — tells you the current write position of an out_channel, as an int64. 💜
• val out_channel_length : out_channel -> int64 — the length of the file behind an out_channel, in int64. 🍓
• val seek_in : in_channel -> int64 -> unit — moves the read position on an in_channel to an int64 offset. 🧚
• val pos_in : in_channel -> int64 — tells you the current read position of an in_channel, as an int64. 🌈
• val in_channel_length : in_channel -> int64 — the length of the file behind an in_channel, in int64. 💀 (in a good way)

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and that's the whole page bestie, it's a short one but honestly it ate. go read them big files. 💅✨

— cute sign-off: this was OCamldoc, dated 2026-06-22, living its life as Stdlib.LargeFile(3) in the OCaml library manual. 🎀💖