clog10(3)

💜 clog10(3) — bestie's guide to the base-10 log of a complex number 💜

okay so this is a page from the Library Functions Manual for clog10, clog10f and clog10l, and honestly? it's giving "niche but iconic". let's get into it 🫶

---

✨ NAME ✨

clog10, clog10f, clog10l — literally just the base-10 logarithm of a complex number, no cap 💅

---

📚 LIBRARY 📚

Math library, bestie! Link it with -lm and it's known as libm. she's a classics girlie 🌸

---

🌈 SYNOPSIS 🌈

#define _GNU_SOURCE         /* See feature_test_macros(7) */
#include <complex.h>

double complex clog10(double complex z);
float complex clog10f(float complex z);
long double complex clog10l(long double complex z);

not me casually dropping #define _GNU_SOURCE first — the comment there points you at feature_test_macros(7) for the deets, iykyk 👑

---

💖 DESCRIPTION 💖

so a call to clog10(z) is equivalent to:

clog(z)/log(10)

or, just as valid, this little baddie right here:

log10(cabs(c)) + I * carg(c) / log(10)

both slay, both correct ✨

the other two functions (clog10f() and clog10l()) do the exact same task, they just work on float and long double instead of double 🦋

⚠️ OKAY LISTEN — if z is close to zero, that's gonna cause an overflow. that's not a vibe. guard your inputs bestie 😭💀

---

🎀 ATTRIBUTES 🎀

for what all these fancy words even mean, go peek at attributes(7) — she explains it better than me fr fr 🙈

• Interface: clog10(), clog10f(), clog10l()
  • Attribute: Thread safety
  • Value: MT-Safe ✅

so yeah — she's MT-Safe, meaning you can call her from multiple threads at once and she will not start drama 🫶✨

---

👑 STANDARDS 👑

GNU. that's it, that's the whole section, periodt 💅

---

🌸 HISTORY 🌸

• Came into the world in glibc 2.1 — a whole legend 🎀
• Heads up though: these identifiers are reserved for future use in C99 and C11. so like... the future said "not me claiming these names" 😭

---

🔥 SEE ALSO 🔥

go read these next, bestie, they're all part of the same little friend group:

• cabs(3)
• cexp(3)
• clog(3)
• clog2(3)
• complex(7)

---

and that's the whole page, you ate it 💖✨

this icon was brought to you by Linux man-pages 6.20, dated 2026-02-08, and yes it's still repping clog10(3) at the very end like a signature on a love letter 💜🦋