memfrob(3)

✨ memfrob(3) ✨

okay bestie so this is a page from the Library Functions Manual 💖 like, the classic Unix manual page situation, but make it make sense. and today we're talking about the most unserious function in all of libc. buckle up. 🎀

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🦋 NAME 🦋

memfrob — memory frobnicate (obfuscate). yes that's really its name. no I will not be explaining what a "frob" is, it's giving ✨vibes✨ only.

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💅 LIBRARY 💅

Standard C library (libc, -lc). she lives in libc, periodt.

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🌸 SYNOPSIS 🌸

#define _GNU_SOURCE             /* See feature_test_macros(7) */
#include <string.h>  // see memory.h(3head)

void *memfrob(size_t n;
              void s[n], size_t n);

okay the _GNU_SOURCE thing is not optional bestie, you literally have to define it to see this one. check feature_test_macros(7) for the whole lore. and yeah, you're pulling in <string.h>, which — plot twist — is memory.h(3head) energy, the header is like. thematically the same girl.

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👑 DESCRIPTION 👑

so like. memfrob() takes the first n bytes of that memory area s and obfuscates them by exclusive-ORing every single character with the number 42. that's it. that's the whole trick. no cap.

the way that this is fully reversible?? 🫶 you just call memfrob() again on the obfuscated memory area and boom, it's back. same function, same bytes, XOR is like that. main character energy honestly.

💀 but listen bestie, this is NOT real encryption. the XOR constant is fixed — it's just 42, forever, always — so this is a proper encryption routine's theater kid cousin, not the actual thing. it is suitable only for hiding strings. do not protect secrets with this. I'm begging. 🥺

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🍓 RETURN VALUE 🍓

it hands you back a pointer to the obfuscated memory area. cute, simple, no drama. ✨

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🔥 ATTRIBUTES 🔥

for what all these terms even mean, go peek at attributes(7), she explains it better than me.

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

so yeah — MT-Safe. you and your threads can all frob together, no fighting, no crashing. slay. 💅

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🧚 STANDARDS 🧚

GNU. that's the whole answer. she's a GNU girlie, not POSIX, not anything else. iykyk. 🌈

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⭐ SEE ALSO ⭐

• memory.h(3head)
• strfry(3)

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and that's the tea, bestie 🩷 go forth and frob responsibly. this slay of a page is from Linux man-pages 6.20, dated 2026-08-05 — love that for us. mwah. 😘💖🦋