cc -pthread -Wall -Wextra -Werror=implicit-function-declaration sched/sched_setscheduler.c -o sched/sched_setscheduler -D_GNU_SOURCE -D_BSD_SOURCE -D_ALL_SOURCE -D_DEFAULT_SOURCE -lm -lpthread -lnetwork -lbsd -latomic sched/sched_setscheduler.c: In function 'main': sched/sched_setscheduler.c:10:22: error: implicit declaration of function 'sched_getscheduler' [-Werror=implicit-function-declaration] 10 | int policy = sched_getscheduler(0); | ^~~~~~~~~~~~~~~~~~ sched/sched_setscheduler.c:18:14: error: implicit declaration of function 'sched_getparam'; did you mean 'sched_getcpu'? [-Werror=implicit-function-declaration] 18 | if ( sched_getparam(0, ¶ms) < 0 ) | ^~~~~~~~~~~~~~ | sched_getcpu sched/sched_setscheduler.c:24:14: error: implicit declaration of function 'sched_setscheduler' [-Werror=implicit-function-declaration] 24 | if ( sched_setscheduler(0, policy, ¶ms) < 0 ) | ^~~~~~~~~~~~~~~~~~ cc1: some warnings being treated as errors