C语言进程链：父进程先打印PID和子进程先打印PID的实现

#include <stdio.h>\n#include <unistd.h>\n\nint main() {\n pid_t child_pid;\n\n printf("Parent PID: %d\n", getpid());\n\n child_pid = fork();\n if (child_pid == 0) {\n printf("Child PID: %d\n", getpid());\n exit(0);\n }\n\n exit(0);\n}\n\n#include <stdio.h>\n#include <unistd.h>\n\nint main() {\n pid_t child_pid;\n\n child_pid = fork();\n if (child_pid == 0) {\n printf("Child PID: %d\n", getpid());\n exit(0);\n }\n\n printf("Parent PID: %d\n", getpid());\n\n exit(0);\n}