SEARCH KEYWORD -- Linux command


  Reset submodule to checkout state in git

Sometimes there would be a submodule or some submodules within one git repository, in some cases the submodule may be out of sync with the checkout state as some files in submodule may be changed unexpectedly. How to reset the submodule to be the same as the original checkout state? Let's take an example that we have a git repository A and there is a submodule called ruby-gems under it. Assuming the submodule at remote origin has commit a. And on our local environment, the repository A has a la...

   GIT RESET,GIT SUBMODULE     2020-09-05 08:30:57

  A guide on installing and running Clickhouse on macOS

ClickHouse is a high-performance open-source columnar database management system developed by Yandex. Here are some of the key features of ClickHouse: Columnar storage: ClickHouse uses a columnar storage format, which allows it to efficiently store and retrieve data by column, rather than by row. This results in much faster query performance, especially for analytical and aggregate queries. Real-time data processing: ClickHouse is designed to handle real-time data processing and can handle bill...

   CLICKHOUSE,MACOS     2023-02-15 06:04:55

  Guide to Implement an SSH Client Using Golang

SSH, short for Secure Shell, is a network protocol used for securely remote logging into other computers on a network. I believe most backend developers are familiar with SSH. Common shell tools used for logging into servers, such as Xshell, SecureCRT, and iTerm2, are all based on the SSH protocol. In Golang, the crypto/ssh package provides functionality for implementing an SSH client. In this article, we will explain in detail how to implement an SSH client using Golang. Creating SSH Client Con...

   SSH CLIENT,GUIDE,SSH,GOLANG     2023-11-11 09:19:29

  Data as code

What is a good command line parser API? A good command line parser should consider below 5 aspects: Support convenient help information generation Support sub commands, for example, git has push,pull,commit sub commands. Support single character option, word option, flag option and option with parameter. Support default option, for example, if no -port is set, set it as 5037 Support usage model, for example, tar's -c and -x is mutually exclusive, they belong to different usage models. Here are...

   Command line,API     2013-08-08 22:40:36

  Latest PHP patch cannot fix the bug

On Wednesday(2012-05-02), a remote code execution vulnerability in PHP was accidentally exposed to the Web, prompting fears that it may be used to target vulnerable websites on a massive scale. The bug itself was traced back to 2004, and came to light during a recent CTF competition.A CERT advisory on the flaw explains: “When PHP is used in a CGI-based setup (such as Apache's mod_cgid), the php-cgi receives a processed query string parameter as command line arguments which allows com...

   PHP,bug,patch,bypassed     2012-05-08 11:20:56

  A simple example of git bisect command

git bisect is a very powerful command for finding out which commit is a bad commit when bug occurs.  The rationale behind this command is that it pin locates the bad commit by divide and conquer. It divides the commit history into two equal parts, then determines whether the bad commit is at the first half or at the other half. This process will continue until the bad commit is located. Here is a really good example created by bradleyboy, this is a simple git repository which demonstr...

   GITHUB,GIT,GIT BISECT     2019-07-12 10:31:51

  Using public key authentication in SSH

SSH is a popular cryptographic network protocol for secure network service operation. It is frequently used in remote server login. For a system administrator or software developer, SSH is frequently used to access remote servers or development servers or testing servers etc.  To login with SSH, there are different authentication mechanisms : password, public key and interactive etc. If a remote server needs to be accessed frequently, password authentication may be too troublesome as p...

   LINUX,DEBUG,SSH,PUBLIC KEY     2016-09-10 05:55:46

  Resolve high CPU usage issue caused by file_get_contents in PHP

Sometimes a Linux server which runs Nginx + PHP-CGI(php-fpm) web service may experience sudden system load increase and the CPU usage is around 100% for many php-cgi processes when checking with top command. If this happens, file_get_contents may be the cause if it's used in the PHP script. In lots of web applications, normally there are lots of API requests based on HTTP. Many PHP developers like to use file_get_contents("http://example.com/") to get the API response because it's simple to...

   PHP,FILE_GET_CONTENTS,PHP-CGI     2018-11-09 21:35:00

  Use DTrace to diagnose gdb issues

A few days ago, I installed the newest 64-bit gdb program (version 7.7.1) on Solaris 10 (X86_64 platform) to debug programs. After playing with the gdb a day, I found 2 issues about gdb:(1) The "set follow-fork-mode child" command doesn't take effect. By default, after the parent process forks the child process, the gdb will track the parent process, so this command can make gdb begin to follow the child process. But this command works OK on Linux.(2) The gdb can't parse the 32-bit application c...

   DTrace, debug, gdb, UNIX     2014-06-28 05:11:20

  The tips of learning Linux kernel

  As the Linux kernel has become one of the most gigantic and complex software project in the world, its complication scare many novices away. In this post, I will give some personal experience on how to learn Linux kernel, and hope these tips can offer some help to newcomers. (1) Download vanilla kernel and install it. Yes, I suggest you can find a physical machine, or if you really don’t have one at hand, virtual machine is also OK. Download the newest vanilla k...

       2017-07-28 22:53:11

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