Übung 5

Assets/Betriebssysteme_uebung/u2-anlage/u2-a1-anlage/Makefile

@@ -0,0 +1,16 @@
+all: p1 p2 p3 p4
+
+p1:
+	cc -o p1 p1.c
+
+p2:
+	cc -o p2 p2.c
+
+p3:
+	cc -o p3 p3.c
+
+p4:
+	cc -o p4 p4.c
+
+clean:
+	rm -f p1 p2 p3 p4

Assets/Betriebssysteme_uebung/u2-anlage/u2-a1-anlage/p1.c

@@ -0,0 +1,11 @@
+#include <stdio.h>
+#include <unistd.h>
+
+int main()
+{
+  printf("%d: code before forking - executed once only\n", getpid());
+
+  fork();
+
+  printf("%d: code after forking - executed by each process\n", getpid());
+}

Assets/Betriebssysteme_uebung/u2-anlage/u2-a1-anlage/p2.c

@@ -0,0 +1,20 @@
+#include <stdio.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+
+int main()
+{
+  if (fork() == 0)
+  { // child proc
+    printf("%d: child created by parent %d; executing 'p4'...\n", getpid(), getppid());
+    execl("p4", "p4", NULL);
+    printf("system call execl(): no success\n");
+  }
+  else
+  { // parent proc
+    printf("%d: parent process\n", getpid());
+  }
+
+  wait(NULL);
+}

Assets/Betriebssysteme_uebung/u2-anlage/u2-a1-anlage/p3.c

@@ -0,0 +1,22 @@
+#include <stdio.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+
+int main()
+{
+  if (fork() == 0)
+  { // child proc
+    printf("%d: child created by parent %d; executing 'p4'...\n", getpid(), getppid());
+    execl("p4", "p4", NULL);
+  }
+  else
+  { // parent proc
+    printf("%d: parent process\n", getpid());
+  }
+
+  fork();
+  printf("%d: terminating\n", getpid());
+
+  wait(NULL);
+}

Assets/Betriebssysteme_uebung/u2-anlage/u2-a1-anlage/p4.c

@@ -0,0 +1,7 @@
+#include <stdio.h>
+#include <unistd.h>
+
+int main()
+{
+  printf("%d: p4 running\n", getpid());
+}

Assets/Betriebssysteme_uebung/u2-anlage/u2-a2-anlage/Makefile

@@ -0,0 +1,13 @@
+all: p5 p6 p7
+
+p5:
+	gcc -o p5 p5.c
+
+p6:
+	gcc -o p6 p6.c
+
+p7:
+	gcc -o p7 p7.c
+
+clean:
+	rm -f p5 p6 p7

Assets/Betriebssysteme_uebung/u2-anlage/u2-a2-anlage/p5.c

@@ -0,0 +1,23 @@
+#include <stdio.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+
+int main()
+{
+  int pid;
+
+  pid = fork();
+
+  if (pid == 0) 
+  { // child proc looping endlessly
+    printf("%d: child ...\n", getpid());
+    for(;10;);
+  } 
+  else 
+  { // parent proc
+    printf("%d: parent; child pid: %d \n", getpid(), pid);
+    wait(NULL); // for child termination
+    printf("%d: parent after wait ... terminating\n", getpid());
+  }
+}

Assets/Betriebssysteme_uebung/u2-anlage/u2-a2-anlage/p6.c

@@ -0,0 +1,7 @@
+#include <stdio.h>
+
+int main()
+{
+  printf("p6: calling getchar()\n");
+  getchar();
+}

Assets/Betriebssysteme_uebung/u2-anlage/u2-a2-anlage/p7.c

@@ -0,0 +1,8 @@
+#include <stdio.h>
+#include <unistd.h>
+
+int main()
+{
+  printf("p7: calling sleep()\n");
+  sleep(100);
+}