daemonize

System2/sendToFile/Makefile

@@ -0,0 +1,12 @@
+CC=gcc
+
+all: main clean
+
+main: main.o
+	$(CC) -o main main.o
+
+main.o: main.c
+	$(CC) -c main.c
+
+clean:
+	rm -f *.o

System2/sendToFile/main.c

@@ -1,23 +1,34 @@
 #include <stdio.h>
 #include <signal.h>
 #include <unistd.h>
+#include <stdlib.h>
+#include <sys/types.h>
 
 void handler(int signum)
 {
-    FILE *fp;
-    fp = fopen("test.txt", "w");
-    fprintf(fp, "coucou, je suis bien en vie!\n");
-    fclose(fp);
-}
-
-int main()
-{
-    signal(SIGUSR1, handler);
-    for (size_t i = 0; i < 30; i++)
+    if (signum == SIGUSR1)
     {
-
-        printf("i = %d, In main\n", i);
-        sleep(1);
+        FILE *fp;
+        fp = fopen("test.txt", "w");
+        fprintf(fp, "coucou, je suis bien en vie!\n");
+        fclose(fp);
+    }
+    else if (signum == SIGUSR2)
+    {
+        exit(EXIT_SUCCESS);
+    }
+    else
+    {
+        printf("received signal %d\n", signum);
     }
-    return 0;
 }
+
+int main(void)
+{
+    if (signal(SIGUSR1, handler) == SIG_ERR)
+        printf("can't catch SIGUSR1\n");
+    if (signal(SIGUSR2, handler) == SIG_ERR)
+        printf("can't catch SIGUSR2\n");
+    for (;;)
+        pause();
+}

System2/sendToFile/test.txt

@@ -0,0 +1 @@
+coucou, je suis bien en vie!