cc -pthread  -Wall -Wextra -Werror=implicit-function-declaration signal/sig2str.c -o signal/sig2str -D_GNU_SOURCE -D_BSD_SOURCE -D_ALL_SOURCE -D_DEFAULT_SOURCE -lm -lpthread -lrt -lcrypt -latomic
signal/sig2str.c: In function ‘main’:
signal/sig2str.c:9:19: error: ‘SIG2STR_MAX’ undeclared (first use in this function); did you mean ‘SIGRTMAX’?
    9 |         char name[SIG2STR_MAX];
      |                   ^~~~~~~~~~~
      |                   SIGRTMAX
signal/sig2str.c:9:19: note: each undeclared identifier is reported only once for each function it appears in
signal/sig2str.c:10:14: error: implicit declaration of function ‘sig2str’ [-Wimplicit-function-declaration]
   10 |         if ( sig2str(SIGUSR1, name) < 0 )
      |              ^~~~~~~
signal/sig2str.c:9:14: warning: unused variable ‘name’ [-Wunused-variable]
    9 |         char name[SIG2STR_MAX];
      |              ^~~~