GELF_GETCAP(3)

💅 GELF_GETCAP(3) 💅

ok so bestie, this is a page from the Library Functions Manual for gelf_getcap and gelf_update_cap, and it lives in the ELF Access Library (libelf, -lelf) — yes the linker flag is literally -lelf, slay. 🎀

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✨ NAME ✨

gelf_getcap, gelf_update_cap — read and update ELF capability information. that's the whole vibe. 💖

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📚 LIBRARY 📚

ELF Access Library (libelf, -lelf) — link it and it's yours, no cap. 🫶

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🧚 SYNOPSIS 🧚

#include <gelf.h>

GElf_Cap *
gelf_getcap(Elf_Data *data, int ndx, GElf_Cap *cap);

int
gelf_update_cap(Elf_Data *data, int ndx, GElf_Cap *cap);

like, look at it. two little functions. absolutely iconic. ⭐

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🌸 DESCRIPTION 🌸

okay so these are the convenience functions — you know, the ones that save you from doing the class-dependent thing by hand — and they're here to retrieve and update class-dependent Elf32_Cap or Elf64_Cap information. yes, class-dependent, meaning 32-bit vs 64-bit, iykyk. 🔥

Argument data is an Elf_Data descriptor, and it needs to be associated with a section of type SHT_SUNW_cap. that's the vibe check it has to pass, fr fr. Argument ndx is the index of the entry you're retrieving or updating — like, which one in the lineup. and the class-independent GElf_Cap structure? that's described over in gelf(3), go peek. 👑

Function gelf_getcap() retrieves the class-dependent entry at index ndx in the data buffer data, and copies it to the destination pointed to by argument cap — but only after translation to class-independent form. so it does the glow-up for you. 💅

Function gelf_update_cap() goes the other way around: it converts the class-independent entry pointed to by argument cap to class-dependent form, and writes it to the entry at index ndx in the data buffer described by argument data. and here's the thing, bestie — gelf_update_cap() signals an error if any of the values in the class-independent representation exceeds the representable limits of the target type. so if your number is too big for the target? nope. error. it will not be squeezing into that outfit. 😭

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🦋 RETURN VALUES 🦋

• Function gelf_getcap() returns the value of argument cap if everything's good, or NULL if it's not. 💀
• Function gelf_update_cap() returns a non-zero value on success, or zero if something went wrong. simple as that. ✨

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🍓 ERRORS 🍓

these functions may fail with the following errors — cop the list:

• [ELF_E_ARGUMENT] — Arguments data or cap were NULL. like, you gave me nothing, bestie.
• [ELF_E_ARGUMENT] — Argument ndx was less than zero or larger than the number of entries in the data descriptor. out of bounds, literally.
• [ELF_E_ARGUMENT] — Data descriptor data was not associated with a section of type SHT_SUNW_cap. wrong section, wrong crowd. 🙈
• [ELF_E_RANGE] — A value was not representable in the target type. too much for the target to hold, periodt.
• [ELF_E_VERSION] — The Elf_Data descriptor denoted by argument data is associated with an ELF object with an unsupported version. the version check said no. 🧚

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💜 SEE ALSO 💜

elf(3), elf_getdata(3), elf_getscn(3), gelf(3) — go read those next, they're the supporting cast and they ate. 👑

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ok that's the whole page, no notes. go forth and handle your capability entries with main character energy. 🌈

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and that's a wrap, bestie — this one's from the Debian edition, dated April 22, 2019, and the page itself is GELF_GETCAP(3). that's the source, the version, and the date, all folded into this cute little sign-off so nothing gets lost. 🎀💖