cc -O2 -pthread -Wall -Wextra -Werror -Wno-error=deprecated -Wno-error=deprecated-declarations unistd/getresgid.c -o unistd/getresgid -D_POSIX_C_SOURCE=202405L -lm -lpthread -lrt -lintl -lcrypt unistd/getresgid.c:11:65: error: 'getresgid' undeclared here (not in a function); did you mean 'setregid'? 11 | int (*foo)(gid_t *restrict, gid_t *restrict, gid_t *restrict) = getresgid; | ^~~~~~~~~ | setregid