On *nix, some processes may not be able to start up, software runs very slowly suddenly and software's "Segment Fault" are some issues faced by many *nix users. Here we show you how to use truss to trace why Vim becomes slow suddenly.Operating system : FreeBSD-5.2.1-releasvim version is 6.2.154, after typing vim on command line, sometimes we need to wait for a few minutes to get into the edit interface and there is no error output. After carefully checking .vimrc and all vim settings, there are no error configuration. Also there are no similar solutions online. Do we need to hack the source co...

Shell is also called command line interface, it is the interface between *nix users and computer. Shell is a program which provides service to access OS kernel services.This article is to introduce some not so well known but useful and interesting knowledge about shell.Wikishell was born almost at the same time as Unix. The first UNIX shell was written by Ken Thompson in 1971 and its name is Thompson sh. It's older than Linux kernel.The default Shell in most *nix and MacOS is bash, bash was created by Brian Fox in 1987, the full name is Bourne Again shell(bash).There are other shells except ba...

ext3 is a journaled file system that is commonly used by the Linux kernel. It is the default file system for many popular Linux distributions, including Debian. Stephen Tweedie. On June 28, 2006, Theodore Ts'o, the principal developer of ext3, announced an enhanced version, called ext4. Today, we will show how to convert ext3 to ext4 format on CentOS.System environment:Release version : CentOS release 5.4(Final)Kernel:  Linux localhost.localdomain 2.6.18-164.el5 #1 SMP Thu Sep 3 03:28:30 EDT 2009 x86_64 x86_64 x86_64 GNU/LinuxAssume the pa...

Yesterday I encountered an issue to delete many log files in my Linux workstation, there were around 100,000 files to be deleted. These are log files and they grow very fast, and we need to delete them frequently. Usually we would use rm -rf * to delete these files, but we may need to wait for a relative long time if there are too many files. So we must adopt some unusual way. Fortunately, we can use rsync to delete mass files in one shot.1. Install rsyncyum install rsync2. Create a new empty foldermkdir /tmp/test3. Use rsync to delete target folderrsync --delete-before -a -H -v --progress --s...

The following are some concise bash programming skills which we may need in our daily programming work.1. Check status of command execution The usual way:echo abcdee | grep -q abcd if [ $? -eq 0 ]; then echo "Found"else echo "Not found"fiConcise way:if echo abcdee | grep -q abc; then echo "Found"else echo "Not found"fiOf course you can remove if...else with following code[Sun Nov 04 05:58 AM] [kodango@devops] ~/workspace $ echo abcdee | grep -q abc && echo "Found" || echo "Not found"Found2. Redirect standard out and standard error to /dev/nullThe usual way:grep"abc" te...

Like majority *nix users, I have been using bash for many years. Sometimes I feel uncomfortable with bash. I tried use some other shells as well such as ksh, tcsh and zsh which I am going to talk about. A few days ago, I found an open source project ranking in the 6th named oh-my-zsh on Github, I downloaded it and had a try with it. It's amazing. We should use zsh to replace bash now.Why do we need to use zsh?Here is a 4 minutes YouTube video which shows many reasons why we should switch from bash to zsh.Reason 0 : zsh is compatible with bashCompatible with bash means that we don't need to spe...

sendmail is a mail client in Linux with many vulnerabilities and tedius configuration steps, many system administrators have disabled using it. Then how do we know what happens if a crontab script executes with error?Actually there are some replacements for sendmail, one is ssmtp, but this application is no longer maintained, we even cannot find its source code on Google. Fortunately, we can use msmtp to replace sendmail. The address : http://msmtp.sourceforge.net/1. InstallationAfter downloading and decompressedm we run./configure --prefix=/usr --libdir=/usr/lib64 --sysconfdir=/etcmakemake in...

HP has just released its first beta version of the webOS, It is said the user experience of webOS is quite impressive, so I immediately had it installed on my PC. There are two versions of Beta release,one embedded version and one Ubuntu version. I briefly share my installation experience of webOS in Linux.In the official document, it says "By 'Linux' we mean 'Ubuntu Linux'", it doesn't support server version and 64 bit version of Ubuntu. Here I use Mint 13.1. Clone source code from githubAddress : https://github.com/openwebos/build-desktopgit command :1git clone https://github.com/openwebos/b...