pipe file

condition test: Whether the condition of judgment is established1. type of condition test: file test; integer comparison; string comparison; logic test2 . Conditional test Syntax:[ operator conditional expression ] equals test operator conditional

The LS Universal list (list) is equivalent to the DOS command dir, which lists all the files under the directory.command using format:ls [OPTION] ... [FILE] ...Let's take a look at ls what options are available for us to choose from, and what each

1, interprocess communication (IPC) inter-process communicationA better understanding of the concept is that inter-process communication is the transmission or exchange of information between different processes .Classification of IPC mechanisms

One, File View command#-1.tac usage:cat [ options ] ... [ file ] ... will be [ file ] or standard input combination output to standard output#-2.tac Usage:TAC [ options ] ... [ file ] ... inverts each specified file by line and writes to standard

linux Basic principles: 1. A small program consisting of a single purpose, combined with a small program to complete complex tasks 2. All documents 3. Avoid capturing user interfaces as much as possible 4. The configuration file is saved in

#!/bin/bash# filename: bingfa.sh# time: 2016/03/9 18:59:05ip= ' Cat /tmp/iplist '            #  Filter Server ipdir= '/tmp '                  #  Target Path                                   thead_num=10                #  custom concurrency number,

Linux operating system based on three-tier system: Kernel-library-shell User name required to access host system: User ID Linux has its own authentication mechanism (authentication), different users need different authorization (Authorization),

Gnu:gnu is not UNIX.Gpl:general public License, general license, copyrightShellGui:graphic User InterfaceWindowsX-windowsGnomeIdeXfaceCli:command Linux InterfaceShBashCshKshZshTcshIDE: Integrated development environmentDll:dynamic link libary

1:linux Network API is divided into: Socker address Api,socker Basic API, network information API1,socker Address API: contains IP addresses and ports (IP, Port). Represents one end of TCP traffic.2,socker Basic API: Create/Name/listen socker,

One, process synchronizationWhat is synchronization? Synchronization means that a task waits for another execution to continue without executing at the same time. As we all know, the process is asynchronous and this nature can cause confusion in the

Shell Introductionin the in Linux systems,theshell is the most commonly used program that listens for user commands, initiates the process specified by the command, and returns the results to the user. He is also a programming language, which is an

File:drwxr-xr-x. 2 root root 60 August 5 21:12 VfioThe first character represents the type of file.File types are:-: Normal file (f)D: Catalog fileB: Block device files (blocks)C: Character device file (character)L: Symbolic Link files (sysbolic

What are the methods for executing system commands using Python? Python is a simple programming language, built-in rich libraries, can easily implement powerful features, in the use of Python framework, often need to use Python to execute system

如何使用Python执行系统命令方法？老男孩IT教育Python is a simple programming language, built-in rich libraries, can easily implement powerful features, in the use of Python framework, often need to use Python to execute system commands, some developers are unfamiliar

Life is endless struggle!The purpose of subprocess is to start a new process and communicate with it.Only one class is defined in the Subprocess module: Popen. You can use Popen to create processes and make complex interactions with processes. Its

Process management ******First, the basic concept1. Processes and ProceduresA process is a running program, a running program may contain multiple processes, and the process is responsible for performing specific tasks in the operating systemA

#!/bin/bash# ——————————————————————————— – #  This example illustrates a technique for simulating multithreading with the wait, read command  #  This technique is often used for multi-host checks, such as SSH login, ping and so on, this single

First, the environmentWindows 7 x64Python 3 +Second, installation1, TESSERACT-OCR Installationhttp://digi.bib.uni-mannheim.de/tesseract/2, Pytesseract installationPip Install Pytesseract3, Pillow installationPip Install PillowThird, the

1. In a Linux system, access the device as a file2. When booting from the Linux kernel, read the file system to be loaded from the file /etc/fstab3. Each file in the Linux file system is identified by the Inode4. Links are divided into: soft

Basic command execution format for Linux#commond Options ... arguments ...Long optionsShort options (some options are available with parameters)A directory is just a path map, which itself belongs to a type of fileLs:list list the files under the