进程的消亡及释放资源

C13-Linux系统编程/process_basic/primerN.c

@@ -0,0 +1,59 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
+#define LEFT  30000000
+#define RIGHT 30000200
+#define N     3
+
+
+/**
+ * @brief    求质数（多进程版）
+ * @details
+ *
+ * @param    argc
+ * @param    argv
+ * @return  int
+ */
+int main(int argc, char **argv)
+{
+    int   i, j, n, mark;
+    pid_t pid;
+
+    for (n = 0; n < N; n++)
+    {
+        pid = fork();
+        if (pid < 0)
+        {
+            perror("fork()");
+            exit(1);   // ! 加入在第三次fork失败时，退出，前两次没有收尸
+        }
+
+        if (pid == 0)
+        {
+            for (i = LEFT + n; i <= RIGHT; i += N)
+            {
+
+                mark = 1;
+                for (j = 2; j < i / 2; j++)
+                {
+                    if (i % j == 0)
+                    {
+                        mark = 0;
+                        break;
+                    }
+                }
+                if (mark)
+                    printf("[%d]%d is a primer\n", n, i);
+            }
+
+            exit(0);   // ! 退出子进程
+        }
+    }
+
+    for (n = 0; n < N; n++)
+        wait(NULL);
+
+    exit(0);
+}