bash

Customize directory colors

You can use the command ls —color (or an alias) to show directories with colours for folders, files, links, etc. However, you may not realise these colours can be easily configured using bashrc and a configuration file. Edit your .bashrc file (in your home directory) to include the following line ... Continue reading


Control memcached from the command line  linux

memcached is a general-purpose distributed memory caching system originally developed by Danga Interactive for LiveJournal but now used by many other sites. It is often used to speed up dynamic database-driven websites by caching data and objects in RAM to reduce the number of times an external data source (such ... Continue reading




Bash Command Substitution  linux

Bash command substitution performs a given command replacing the marker with the resulting standard output. It is particularly useful when you want to store the output of a command in a variable or as an alternative method of chaining multiple commands together. Bash command substitution is achieved by wrapping your ... Continue reading


Remove duplicate lines from text files (with sort)

A quick method to remove duplicates from text files - including for example CSV files - where multiple records have been added (perhaps automatically) at different times resulting in multiple copies of the same record scattered throughout the file. Here is a simple one-liner bash command to remove duplicates using sort. Continue reading


Control Console with SysReq  linux

System request (often abbreviated SysRq or Sys Req) is a key on keyboards for PCs that has no standard use. This key can be traced back to the operator interrupt key of the IBM System/370 mainframe computer. But under Linux there’s a bunch of useful things available via ... Continue reading






Find all running processes of a program

Find the pids of all instances/processes of a given program running on your system Open a terminal and enter ps ax | grep "firefox" …replacing ‘firefox’ with the name of the program you are looking for. The columns in the output are as follows: (1) pid ‘process id’ (2) tty ... Continue reading







Control-R Through Your History  linux

Interactively search through your command line history with a simple keyboard shortcut. At a new shell prompt (bash or Terminal.app on Mac) press Ctrl-R Start typing the search string to lookup in your bash history. As you type the top matching command in your history will appear. Hit Return ... Continue reading


Use screen to manage persistent sessions  linux

GNU Screen is a command-line application that allows use of multiple virtual sessions within a single real terminal or remote session. Importantly, it allows for persistent running of command-line applications independent of the shell that initiated them program, meaning active applications can persist during disconnection. Continue reading