Initial commit

kapitel17/sig-client.c

@@ -0,0 +1,61 @@
+#define _XOPEN_SOURCE 500
+#include <stdio.h>
+#include <signal.h>
+#include <unistd.h>
+#include <sys/types.h>
+
+void printUsage(char *arg);
+
+int main(int argc, char* argv[])
+{
+    FILE *fp;
+    int opt;
+    pid_t process_id;
+    char pidfile[] = "/tmp/daemon-sig-ex.pid";
+
+    /* Kontrollera ifall PID-filen finns */
+    if ( (fp = fopen(pidfile, "r")) == 0 )
+    {
+        fprintf(stderr, "Ingen PID-fil, körs verkligen demonen?\n");
+        return 1;
+    }
+    /* Läs in PID till process_id variabeln */
+    fscanf(fp, "%d", &process_id);
+
+    /* Om inga argument angavs, skriv ut demonens PID */
+    if (argc == 1)
+        printf("Demonen körs med PID: %d\n", process_id);
+
+    /* Behandla argument till programmet */
+    while ((opt = getopt(argc, argv, "utqh")) != -1)
+    {
+        switch (opt)
+        {
+        case 'u':
+            kill(process_id, SIGUSR1);
+            break;
+        case 't':
+            kill(process_id, SIGTERM);
+            break;
+        case 'q':
+            kill(process_id, SIGQUIT);
+            break;
+        case 'h':
+            printUsage(argv[0]);
+            return 0;
+        default:
+            printUsage(argv[0]);
+            return 1;
+        }
+    }
+    return 0;
+}
+
+void printUsage(char *arg)
+{
+    fprintf(stderr, "Usage: %s [-u] [-t] [-q] [-h]\n"
+            "-u = send SIGUSR1 to daemon\n"
+            "-t = send SIGTERM to daemon\n"
+            "-q = send SIGQUIT to quit the daemon\n"
+            "-h = display help\n", arg);
+}