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1.整理TCP三次握手、四次挥手图 三次握手： ​ 四次挥手： 2.基于TCP开发一款远程CMD程序 客户端连接服务器后，可以向服务器发送命令 服务器收到命令后执行，无论执行是否成功，无论执行几遍，都将执行结果返回给客户端 注意: 执行系统指令使用subprocess模块完成. # 服务端 from socket import * import subprocess ip_port = ('127.0.0.1', 9003) bufsize = 1024 udp_server = socket(AF_INET, SOCK_DGRAM) udp_server.bind(ip_port) while True: cmd, addr = udp_server.recvfrom(bufsize) print('用户命令----->', cmd) res = subprocess.Popen(cmd.decode('utf-8'), shell=True, stderr=subprocess.PIPE, stdin=subprocess.PIPE, stdout=subprocess.PIPE) stderr = res.stderr.read() stdout = res.stdout.read() udp_server.sendto(stderr, addr) udp_server

1.整理TCP三次握手、四次挥手图 三次握手 四次挥手 2.基于TCP开发一款远程CMD程序 客户端连接服务器后，可以向服务器发送命令 服务器收到命令后执行，无论执行是否成功，无论执行几遍，都将执行结果返回给客户端 注意: 执行系统指令使用subprocess模块完成. 服务端 import socket import subprocess server = socket.socket() server.bind(('127.0.0.1', 8000)) server.listen(5) print('start...') while True: conn, client_addr = server.accept() while True: print('from client:', client_addr) cmd = conn.recv(1024) if len(cmd) == 0: break print('cmd:', cmd) obj = subprocess.Popen(cmd.decode('utf8'), # 输入的cmd命令 shell=True, # 通过shell运行 stderr=subprocess.PIPE, # 把错误输出放入管道，以便打印 stdout=subprocess.PIPE) # 把正确输出放入管道，以便打印 stdout = obj

First question, ahhhh! Does anyone know / have info about why mongoose writes its debug log to stderr? Is there anyway to write it to stdout? The debug option accepts a function instead of a boolean: mongoose.set("debug", function (collection, method, paramA, paramB, paramC) { console.log(collection) console.log(method) console.log(paramA) console.log(paramB) console.log(paramC) }) The reason I put paramA, paramB, paramC is because the arguments are dependent upon the method and options being used: Person.create({firstName: "john"}, callback) // people // insert // {firstName: "john"} //

java -jar XXX.jar & 命令结尾没有 “&” ，则变成 “java -jar XXX.jar ” ，表示在当前ssh窗口，可按CTRL + C打断程序运行，或者直接关闭窗口，则程序直接退出 命令结尾添加 “&” ，则变成 “java -jar XXX.jar &” ，表示在当窗口关闭时，程序才会中止运行。&代表让该命令在后台执行。 nohup java -jar XXX.jar > Log.log & 或者 nohup java -jar XXX.jar >> Log.log & 命令 "nohup java -jar XXX.jar &" 部分，表示不挂断运行命令,当账户退出或终端关闭时,程序仍然运行。注意，该作业的所有输出被重定向到nohup.out的文件中。 命令 "nohup java -jar XXX.jar > Log.log &" 部分，表示不挂断运行命令,当账户退出或终端关闭时,程序仍然运行，并且该作业的所有输出被重定向到Log.log的文件中。“ > Log.log ” 该命令就是指定日志输出的文件。 ">>"表示将输出以追加的方式重定向到Log.log中。 nohup java -jar XXX.jar > Log.log 2>&1 & 或者 nohup java -jar XXX.jar >> Log.log 2>&1 & 或者 nohup

Suppose we have: sub test { print "testing\n"; } If there is a case where I want to have it print to stderr instead of stdout, is there a way I can call the subroutine to do this? Or can I capture the output to a variable and then use warn? I'm fairly new to perl. Yes there is. print sends its output to the "selected" filehandle, which is usually STDOUT . But Perl provides the select function for you to change it. select(STDERR); &test; # send output to STDERR select(STDOUT); # restore default output handle The select function returns the previously selected filehandle, so you can capture it

Python实现的循环定时服务功能，类似于Linux下的contrab功能。主要通过定时器实现。 注：Python中的threading.timer是基于线程实现的，每次定时事件产生时，回调完响应函数后线程就结束。而Python中的线程是不能restart的，所以这种循环定时功能必须要在每次定时响应完成后再重新启动另一个定时事件。 #!/usr/bin/env python # -*- coding: utf-8 -*- # import subprocess from threading import Timer import time import os import sys if os.name == 'posix': def become_daemon(our_home_dir='.', out_log='/dev/null', err_log='/dev/null', umask=0o022): "Robustly turn into a UNIX daemon, running in our_home_dir." # First fork try: if os.fork() > 0: sys.exit(0) # kill off parent except OSError as e: sys.stderr.write("fork #1 failed: (%d) %s\n

I'm writing a GUI application, using Qt, which links to a third-party DLL that sometimes sends error messages to stderr. I'd like these error messages to be displayed in a window within my GUI. I couldn't find an established way to redirect stderr (as opposed to std::cerr) even after much searching, so I wrote the following class myself: class StdErrRedirect : public QObject { Q_OBJECT public: // Constructor StdErrRedirect(QTextEdit *errorLog, QObject *parent = NULL); // Destructor ~StdErrRedirect(); private slots: void fileChanged(const QString &filename); private: QFile tmp;

A bash script is run from cron, stderr is redirected to a logfile, this all works fine. The code is: */10 5-22 * * * /opt/scripts/sql_fetch 2>> /opt/scripts/logfile.txt I want to prepend the date to every line in the log file, this does not work, the code is: */10 5-22 * * * /opt/scripts/sql_fetch 2>> ( /opt/scripts/predate.sh >> /opt/scripts/logfile.txt ) The predate.sh script looks as follows: #!/bin/bash while read line ; do echo "$(date): ${line}" done So the second bit of code doesn't work, could someone shed some light? Thanks. I have a small script cronlog.sh to do this. The script code

What is the easiest way to create my own std::cerr so that it is line-by-line thread-safe. I am preferably looking for the code to do it. What I need is so that a line of output (terminated with std::endl ) generated by one thread stays as a line of output when I actually see it on my console (and is not mixed with some other thread's output). Solution : std::cerr is much slower than cstdio. I prefer using fprintf(stderr, "The message") inside of a CriticalSectionLocker class whose constructor acquires a thread-safe lock and the destructor releases it. If available, osyncstream (C++20) solves