From 0f0c9a48dc098a692bd5ada9d01f800ceca163ff Mon Sep 17 00:00:00 2001
From: MAO Dongyang <suchcp@gmail.com>
Date: Wed, 29 Mar 2023 17:13:13 +0200
Subject: [PATCH] daemonize

---
 System2/daemonize/Makefile   | 12 ++++++
 System2/daemonize/coucou.txt |  1 +
 System2/daemonize/main.c     | 75 ++++++++++++++++++++++++++++++++++++
 System2/daemonize/test.txt   |  0
 System2/sendToFile/Makefile  | 12 ++++++
 System2/sendToFile/main.c    | 39 ++++++++++++-------
 System2/sendToFile/test.txt  |  1 +
 7 files changed, 126 insertions(+), 14 deletions(-)
 create mode 100644 System2/daemonize/Makefile
 create mode 100644 System2/daemonize/coucou.txt
 create mode 100644 System2/daemonize/main.c
 create mode 100644 System2/daemonize/test.txt
 create mode 100644 System2/sendToFile/Makefile

diff --git a/System2/daemonize/Makefile b/System2/daemonize/Makefile
new file mode 100644
index 0000000..016db65
--- /dev/null
+++ b/System2/daemonize/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
\ No newline at end of file
diff --git a/System2/daemonize/coucou.txt b/System2/daemonize/coucou.txt
new file mode 100644
index 0000000..940faab
--- /dev/null
+++ b/System2/daemonize/coucou.txt
@@ -0,0 +1 @@
+coucou, je suis bien en vie!
diff --git a/System2/daemonize/main.c b/System2/daemonize/main.c
new file mode 100644
index 0000000..ff11d96
--- /dev/null
+++ b/System2/daemonize/main.c
@@ -0,0 +1,75 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <signal.h>
+#include <string.h>
+#include <stdbool.h>
+
+bool daemonize()
+{
+    pid_t pid = fork();
+    if (pid < 0)
+    {
+        return false;
+    }
+    if (pid > 0)
+    {
+        exit(0);
+    }
+    if (setsid() < 0)
+    {
+        return false;
+    }
+    pid = fork();
+    if (pid < 0)
+    {
+        return false;
+    }
+    if (pid > 0)
+    {
+        exit(0);
+    }
+    umask(0);
+    chdir("/");
+    FILE *fp;
+    fp = fopen("/Users/mdy/Development/langage_C/System2/daemonize/test.txt", "w");
+    close(STDIN_FILENO);
+    close(STDOUT_FILENO);
+    dup(fileno(fp));
+    close(STDERR_FILENO);
+    dup(fileno(fp));
+    return true;
+}
+
+void handler(int signum)
+{
+    if (signum == SIGUSR1)
+    {
+        FILE *fp;
+        fp = fopen("/Users/mdy/Development/langage_C/System2/daemonize/coucou.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);
+    }
+}
+
+int main(void)
+{
+    daemonize();
+    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();
+}
diff --git a/System2/daemonize/test.txt b/System2/daemonize/test.txt
new file mode 100644
index 0000000..e69de29
diff --git a/System2/sendToFile/Makefile b/System2/sendToFile/Makefile
new file mode 100644
index 0000000..016db65
--- /dev/null
+++ b/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
\ No newline at end of file
diff --git a/System2/sendToFile/main.c b/System2/sendToFile/main.c
index 7b4502f..54ed887 100644
--- a/System2/sendToFile/main.c
+++ b/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();
+}
\ No newline at end of file
diff --git a/System2/sendToFile/test.txt b/System2/sendToFile/test.txt
index e69de29..940faab 100644
--- a/System2/sendToFile/test.txt
+++ b/System2/sendToFile/test.txt
@@ -0,0 +1 @@
+coucou, je suis bien en vie!