问题

用python监控进程占用硬件资源时，手动执行正常运行，定时任务执行出错
在centos的定时任务中，用python的os模块执行top命令时终端没有输出

cmd = 'top -d 1 -n 1 -p {} | grep -E "PID|{}|%Cpu|buff/cache" '.format(process_id, process_id, )
sys_out = os.popen(cmd)
sys_out = sys_out.read()

修复

1. top -n 1不能在 crontab中使用，要加一个参数top -b -n 1
2. 用 /bin/top 代替 top 命令

cmd = '/bin/top -b -d 1 -n 1 -p {} | grep -E "PID|{}|%Cpu|buff/cache" '.format(process_id, process_id, )sys_out = os.popen(cmd)
sys_out = sys_out.read()  

引用

https://blog.51cto.com/zdz8207/3552214

源代码

def record_process_occupy(process_id=0, process_log_file="", ):"""记录一条这个进程的资源占用情况:param process_id: 进程的ID:param log_file: 保存top输出的文件:return: None"""cmd = '/bin/top -b -d 1 -n 1 -p {} | grep -E "PID|{}|%Cpu|buff/cache" '.format(process_id, process_id, )sys_out = os.popen(cmd)print(cmd)sys_out = sys_out.read()sys_out = sys_out.replace("\x1b[7m", "")sys_out = sys_out.replace("\x1b(B\x1b[m\x1b[39;49m\x1b(B\x1b[m\x1b[39;49m\x1b[K", "")sys_out = sys_out.replace("\x1b(B\x1b[m\x1b[39;49m\x1b[K", "")sys_out = sys_out.replace("\x1b(B\x1b[m\x1b[39;49m", "")sys_out = sys_out.replace("\x1b(B\x1b[m", '')sys_out = sys_out.replace("\x1b[1m", "")sys_out = sys_out.split('\n')assert len(sys_out) >= 4# print(sys_out)first_line = "time,"first_line += "us,sy,ni,id,wa,hi,si,st,"first_line += "total, free, used, buff/cache,"first_line += "PID,USER,PR,NI,VIRT,RES,SHR,S,%CPU,%MEM,TIME+,COMMAND"line = ",".join([datetime.datetime.now().strftime("%Y-%m-%d %H:%M:%S"),",".join([x for x in sys_out[0].replace(",", " ").split(" ") if x.replace(".", "").isdigit()]),  # cpu",".join([x for x in sys_out[1].replace(",", " ").split(" ") if x.replace(".", "").isdigit()]),  # mem",".join([x for x in sys_out[3].split(" ") if x]),  # 进程])# print(first_line)# print(line)print("process_log_file", process_log_file)if not process_log_file:process_log_file = os.path.join(BACKUP_PATH, "process_{}_resource_occupy.csv".format(process_id))print()print("process_log_file:", process_log_file)is_new_file = not os.path.exists(process_log_file)with open(process_log_file, 'a') as f:if is_new_file:f.write(first_line + "\n")f.write(line + "\n")return True