Category Archives: shell tips

bash histogram

I would like to generate a streamable histgram that runs in bash. Given an input stream of integers (from stdin or a file), I would like to transform each integer to that respective number of "#" up to the length … Continue reading

Posted in bash, shell tips

VLC remote control

Recently I was using VLC to listen to music, as I often do, and I wanted to pause without getting out of bed. Lazy? Yes! I learned that VLC includes a slew of remote control interfaces, including a built-in web … Continue reading

Posted in shell tips

datsize, simple command line row and column count

Lately I've been working with lots of data files with fixed rows and columns, and have been finding myself doing the following a lot: Getting the row count of a file, twarnock@laptop:/var/data/ctm :) wc -l lda_out/final.gamma 3183 lda_out/final.gamma twarnock@laptop:/var/data/ctm :) … Continue reading

Posted in bash, shell tips

Getting the most out of your ssh config

I typically find myself with voluminous bashrc files filled with aliases and functions for connecting to specific hosts via ssh. I would like an easier way to manage the various ssh hosts, ports, and keys. I typically maintain an ssh-agent … Continue reading

Posted in shell tips, ssh

git, obliterate specific commits

I would like to obliterate a series of git commits between two points, we'll call these the START and END commits. First, determine the SHA1 for the two commits, we'll be forcefully deleting everything in between and preserving the END … Continue reading

Posted in shell tips

vim: Visual mode

I have been using vim for years and am consistently surprised at the amazing things it can do. Vim has been around longer than I have been writing code, and its predecessor (Vi) is as old as I am. Somehow … Continue reading

Posted in shell tips, vim

vim: tags and tabs

Previously, I discussed using vim and screen with automagic titles. The great part about working with vim and screen is that I can work from anywhere with minimal setup, and when working remotely I can pick up the cursor exactly … Continue reading

Posted in shell tips, vim

vim and screen, automagic titles

Previously, I discussed using multiuser screen so that I could concurrently access a shared screen session across multiple remote hosts (from work, from home, from my phone, etc). I would like to augment screen such that the titles would always … Continue reading

Posted in bash, shell tips, vim

multiuser screen

Previously, I discussed using GNU screen as a window manager. I would like to access my screen session concurrently from multiple hosts (say, at work, at home, and even remotely on my phone). I would also like to define default … Continue reading

Posted in bash, shell tips

scripting Photoshop for stop motion

I would like a simple and quick way to save a copy of an image in Photoshop, with an auto-incrementing filename. Ideally, a single button to capture a frame in a stop motion animation. In other words, I would like … Continue reading

Posted in html, javascript, shell tips

locking and concurrency in python, part 2

Previously, I created a "MultiLock" class for managing locks and lockgroups across a shared file system. Now I want to create a simple command-line utility that uses this functionality. To start, we can create a simple runone() function that leverages … Continue reading

Posted in python, shell tips, software arch.

zip archive in python

I would like to create zip archives within a python batch script. I would like to compress individual files or entire directories of files. You can use the built-in zipfile module, and create a ZipFile as you would a normal … Continue reading

Posted in python, shell tips

chaining ssh tunnels

Imagine you're working within a private home network and need to connect to an Oracle database within a corporate network accessible only through a bastion host hidden within the corporate network. Odd as that sounds, it's a typical network configuration, … Continue reading

Posted in bash, shell tips, ssh

timeout command in python

I would like to add a timeout to any shell command such that if it does not complete within a specified number of seconds the command will exit. This would be useful for a any long-running command where I'd like … Continue reading

Posted in python, shell tips

sqlplus, utility scripts

I would like to use sqlplus in development projects, and I would like it to be easy to use. First off, I want command-history and tab-completion. The easiest approach is to use rlwrap which uses the GNU readline library as … Continue reading

Posted in oracle, shell tips