signals/signal_functions.c

+/* signal_functions.c
+
+   Various useful functions for working with signals.
+*/
 #define _GNU_SOURCE
 #include <string.h>
 #include <signal.h>
 #include "signal_functions.h"           /* Declares functions defined here */
 #include "tlpi_hdr.h"
 
 /* NOTE: All of the following functions employ fprintf(), which
    is not async-signal-safe (see Section 21.1.2). As such, these
    functions are also not async-signal-safe (i.e., beware of
    indiscriminately calling them from signal handlers). */
 
 void                    /* Print list of signals within a signal set */
 printSigset(FILE *of, const char *prefix, const sigset_t *sigset)
 {
     int sig, cnt;
 
     cnt = 0;
     for (sig = 1; sig < NSIG; sig++) {
         if (sigismember(sigset, sig)) {
             cnt++;
             fprintf(of, "%s%d (%s)\n", prefix, sig, strsignal(sig));
         }
     }
 
     if (cnt == 0)
         fprintf(of, "%s<empty signal set>\n", prefix);
 }
 
 int                     /* Print mask of blocked signals for this process */
 printSigMask(FILE *of, const char *msg)
 {
     sigset_t currMask;
 
     if (msg != NULL)
         fprintf(of, "%s", msg);
 
     if (sigprocmask(SIG_BLOCK, NULL, &currMask) == -1)
         return -1;
 
     printSigset(of, "\t\t", &currMask);
 
     return 0;
 }
 
 int                     /* Print signals currently pending for this process */
 printPendingSigs(FILE *of, const char *msg)
 {
     sigset_t pendingSigs;
 
     if (msg != NULL)
         fprintf(of, "%s", msg);
 
     if (sigpending(&pendingSigs) == -1)
         return -1;
 
     printSigset(of, "\t\t", &pendingSigs);
 
     return 0;
 }