Linux = Linus Unix

GNU = GNU is Not Unix

GCC = GNU C Compiler

gcc -lxyz

  link with libxyz.a (static) or libxyz.so (dynamic, shared object)

---

$ alias GCC
alias GCC='gcc -std=c11 -pedantic -Wall'

$ GCC a1.c
$ ./a.out
 LONG_MAX = 9223372036854775807
errno = 13
/etc/shadow: Permission denied

# 32-bit memory model:

$ GCC -m32 a1.c
$ ./a.out
 LONG_MAX = 2147483647
errno = 13
/etc/shadow: Permission denied

$ GCC ctime.c
$ ./a.out
ctime = Mon Aug 29 17:42:29 2022
$