[SP/P5] Added solutions to some exercises from today

1 files changed, 54 insertions, 0 deletions

diff --git a/Year 3/System programming/Practicum5/ex2.c b/Year 3/System programming/Practicum5/ex2.c
new file mode 100644
index 0000000..88b337c
--- /dev/null
+++ b/Year 3/System programming/Practicum5/ex2.c
@@ -0,0 +1,54 @@
+#include <sys/types.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+int main() {
+	int f = open("test.txt", O_CREAT | O_WRONLY | O_TRUNC, 0755);
+	if (f < 0) {
+		perror("open test.txt");
+		return 2;
+	}
+
+	pid_t fpid = fork();
+
+	if (fpid < 0) {
+		perror("fork");
+		return 1;
+	}
+
+	if (fpid == 0) { // in child
+		sleep(2);
+		int ws = write(f, "From Child 1\n", 13);
+
+		if (ws < 0) {
+			perror("write from child");
+			return 3;
+		}
+
+		sleep(5);
+		ws = write(f, "From Child 2\n", 13);
+
+		if (ws < 0) {
+			perror("write from child");
+			return 3;
+		}
+	}
+	else {
+		int ws = write(f, "From Parent 1\n", 14);
+
+		if (ws < 0) {
+			perror("write from child");
+			return 3;
+		}
+
+		sleep(3);
+		ws = write(f, "From Parent 2\n", 14);
+
+		if (ws < 0) {
+			perror("write from child");
+			return 3;
+		}
+	}
+}