Unix Prog: Signal Reference APIs

1. sys_siglist

Definition:

 ubuntu@ip-172-31-23-227:~$ less /usr/include/signal.h  
 ......  
 /* Names of the signals. This variable exists only for compatibility.  
   Use `strsignal' instead (see <string.h>). */  
 extern const char *const _sys_siglist[_NSIG];  
 extern const char *const sys_siglist[_NSIG];  
 ......  

Example:
siglist.c:

 #include<stdio.h>  
 #include<stdlib.h>  
 #include<unistd.h>  
 #include<signal.h>  
   
 int main(int argc, char* argv[])  
 {  
  printf("SIGCONT: %s\n", sys_siglist[SIGCONT]);  
  printf("SIGCHLD: %s\n", sys_siglist[SIGCHLD]);  
  exit(0);  
 }  

shell:

 ubuntu@ip-172-31-23-227:~$ ./siglist.out  
 SIGCONT: Continued  
 SIGCHLD: Child exited  

2. psignal

Definition:

 ubuntu@ip-172-31-23-227:~$ less /usr/include/signal.h  
 ......  
 /* Print a message describing the meaning of the given signal number. */  
 extern void psignal (int __sig, const char *__s);  
 ......  

Example:
psignal.c:

 #include<stdio.h>  
 #include<stdlib.h>  
 #include<unistd.h>  
 #include<signal.h>  
   
 int main(int argc, char* argv[])  
 {  
  psignal(SIGCONT, "SIGCONT:");  
  psignal(SIGCHLD, "SIGCHLD:");  
   
  exit(0);  
 }  

shell:

 ubuntu@ip-172-31-23-227:~$ ./psignal.out  
 SIGCONT:: Continued  
 SIGCHLD:: Child exited  

3. strsignal

System Definition:

 ubuntu@ip-172-31-23-227:~$ less /usr/include/string.h  
 ......  
 /* Return a string describing the meaning of the signal number in SIG. */  
 extern char *strsignal (int __sig) __THROW;  
 ......  

Example:
strsig.c:

 #include<stdio.h>  
 #include<stdlib.h>  
 #include<string.h>  
 #include<signal.h>  
   
 int main(int argc, char* argv[])  
 {  
  char *p = strsignal(SIGCONT);  
  printf("SIGCONT: %s\n", p);  
   
  p = strsignal(SIGCHLD);  
  printf("SIGCHLD: %s\n", p);  
   
  exit(0);  
 }  

shell:

 ubuntu@ip-172-31-23-227:~$ ./strsig.out  
 SIGCONT: Continued  
 SIGCHLD: Child exited  

4. sig2str, str2sig

Definition: