Linking unistd.h when using CC compiler (Solaris)

Question

I need to link <unistd.h> in my program using CC compiler on Solaris. When I needed to link <math.h> or <curses.h> I just used Google to find -lm and -lcurses flags but this time Google didn't help. How to find out in which lib*something* is <unistd.h> located?

`` is a header that is included. It is not linked in. Neither is a `` **in** the `libm`; it just *describes its contents*. — Antti Haapala -- Слава Україні, Dec 23 '17 at 22:51
the functions exposed by `unistd.h` are all contained in the `libc.so` library, which is always linked in, so nothing has to be done at link time (unlike the libcurses.so and libmath.so libraries.) — user3629249, Dec 24 '17 at 04:26

score 3 · Accepted Answer · edited Dec 23 '17 at 23:01

For any given function, the man page tells you both what headers to include and what libraries to link.

For example, the ceil function:

Synopsis

c99 [ flag... ] file... -lm [ library... ]
#include <math.h>

double ceil(double x);

float ceilf(float x);

long double ceill(long double x);

It tells you to #include <math.h> and to link with -lm.

Most functions declared in <unistd.h> don't require any additional libraries to link in, but when in doubt check the man pages.

Linking unistd.h when using CC compiler (Solaris)

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