Add process

process

@@ -0,0 +1,38 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+int main(int argc, char const *argv[])
+{
+	int p1=fork();
+	if (p1==0)
+	{
+		/* code */
+		for (int i = 0; i < 2; ++i)
+		{
+			/* code */
+			printf("child: %d\n",getpid());
+		}
+	}else if(p1>0){
+		int p2=fork();
+		if(p2==0){
+			for (int i = 0; i < 3; ++i)
+			{
+				/* code */
+				printf("child: %d\n",getpid());
+			}
+		}else if(p2>0){
+			for (int i = 0; i < 4; ++i)
+			{
+				/* code */
+				printf("parent: %d\n",getpid());
+			}
+		}else{
+			printf("Failed to create p2.\n");
+			exit(1);
+		}
+	}else{
+		printf("Failed to create p1.\n");
+		exit(1);
+	}
+	return 0;
+}