ELF_NEWSCN(3)

✨ ELF_NEWSCN ✨

okay bestie, welcome to elf_newscn(3) from the Libelf Programmer's Manual 💖 this one's a lil function that makes brand new sections, and honestly? it's giving main character energy for your ELF file. let's get into it 🫶

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🌸 NAME 🌸

elf_newscn — create a new section for an ELF descriptor 💅

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🎀 SYNOPSIS 🎀

#include <libelf.h>

Elf_Scn *elf_newscn(Elf * elf");"

(yes, that's literally what it says in the manual, no cap — we keep it verbatim 🙈)

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🦋 DESCRIPTION 🦋

So like, the elf_newscn() function creates a new section descriptor for the ELF descriptor elf. That's the whole vibe. ✨

Every single time you call elf_newscn(), it appends a new section to the internal list of sections for that ELF descriptor. Not just one and done — every call, another one, like it's collecting them. 💖 It also creates a corresponding empty section header, which is zero-initialized and marked dirty. And listen — if elf doesn't have any sections yet, then elf_newscn will also create the null section with sh_type SHT_NULL at section index 0. Iconic behaviour honestly.

A newly created section has no name or type, so it is not ready to go out looking like that 😭 it must be properly initialized before calling elf_update(). Use elf32_getshdr() or elf64_getshdr() to obtain the section header structure, then populate the required fields. And use elf_newdata() to associate one or more data buffers with the new section. Like, dress it up before it leaves the house. 👑

🚨 The section with index 0 (the null section) is reserved and cannot have data added to it. And elf_newscn() will never return this section. So don't go looking for it, she's not coming. 💀

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🌈 PARAMETERS 🌈

• elf — an ELF descriptor that must at least have an Elf32_Ehdr or Elf64_Ehdr associated with it. minimum requirement bestie, no bare descriptors allowed 🎀

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⭐ RETURN VALUE ⭐

On success, elf_newscn() returns a pointer to a new section descriptor. slay. 🎉

On failure, it returns NULL and sets elf_errno.

And if elf is NULL, then NULL is returned without setting elf_errno. like, it just silently hands you the L, no extra info. 💀

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💜 SEE ALSO 💜

• elf32_getshdr(3)
• elf64_getshdr(3)
• elf_getdata(3)
• elf_newdata(3)
• elf_update(3)
• libelf(3)
• elf(5)

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👑 ATTRIBUTES 👑

• Interface: elf_newscn()
• Attribute: Thread safety
• Value: MT-Safe

so basically: she's thread safe, go off, run her everywhere 🧚✨

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💌 REPORTING BUGS 💌

Found a bug? don't be shy, report it to <elfutils-devel@sourceware.org> or hit up https://sourceware.org/bugzilla/. they wanna hear it fr fr 🐛🫶

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and that's the whole page bestie!! this one came from Libelf, dated 2025-06-30, and it's your girl ELF_NEWSCN(3) signing off 💅💖 go make some sections, but remember to initialize them before elf_update() or it's gonna be a mess 😭✨