Claus Witt » bash

Bash script for editing the hosts file

Claus Witt — Wed, 04 Nov 2009 09:02:46 +0000

I just read a post about local development in apache by Jesper Rasmussen and thought one thing was missing. I usually test my sites and applications locally with the real domain – to ensure that functionality based on the url works as expected. However this means editing the hosts file several times a day. Now I have made a small shellscript that will add and remove lines from the hosts file.

#! /bin/bash
DEFAULT_IP=127.0.0.1
IP=${3:-$DEFAULT_IP}

case "$1" in
  add)
        echo "$IP $2"  >> /etc/hosts
        ;;
  remove)
        sed -ie "\|^$IP $2\$|d" /etc/hosts
        ;;

  *)
        echo "Usage: "
		echo "hosts.sh [add|remove] [hostname] [ip]"
		echo
		echo "Ip defaults to 127.0.0.1"
		echo "Examples:"
		echo "hosts.sh add testing.com"
		echo "hosts.sh remove testing.com 192.168.1.1"
        exit 1
        ;;
esac

exit 0

As you can see the script defaults the ip to 127.0.0.1 for easy creation of local domains. Next step is to create a quicksilver (and a gnome do) plugin for easy creation without ever touching the terminal. (Even though we all love the terminal, right?)

Converting Filenames to Lowercase with Bash

Claus Witt — Wed, 03 Jun 2009 07:24:36 +0000

Once again I have a bash-oneliner. For some reason it is all I blog about at the moment.

I had an import script for importing demo files (in mp3 format) to a database used at Voicearchive. Only problem the import script depended on the files being named precisely according to a specific rule. But for some reason some times it was named with uppercase letters, and sometimes with lowercase letters. I decided to rename all files to lowercase, and change the importscript accordingly.

find . -maxdepth 1 -type f -execdir rename 'y/A-Z/a-z/' '{}' \;

Bash Oneliner for Counting Files

Claus Witt — Thu, 14 May 2009 09:56:51 +0000

I needed to find a way to count the number of files in a directory and only output that number. Bash is still my best friend for this sort of thing – especially with a little help from google.

ls -1 | wc -l

by the way – the answer was 2062 files.

Renaming file extensions with bash script

Claus Witt — Thu, 30 Apr 2009 06:58:04 +0000

A couple of weeks ago I had to rename the file extension of several view scripts from html (from my own mvc framework) to phtml (zend framework). I found, as always, bash to be my friend.

for i in *
do
  ( file $i | grep html ) && mv $i $(echo $i | sed s/html$/phtml/)
done

How I sorted All My Mp3’s With a Simple Bash Script

Claus Witt — Thu, 12 Mar 2009 21:00:00 +0000

First of all, the headline is a lie. I am in the process of copying all mp3 files that we in our household have had on a number of different machines to one central server, which all computers talk to via webdav. But since we have had a lot of different naming schemes and ways of sorting files we needed some sort of uniform naming of files and directories. We decided on the ever so nice /Artist/Album/01_Title.mp3. But since we have a lot of mp3’s, this seemed a daunting task.

In comes bash. 6 lines of code is all it takes.

#!/bin/bash
end="/destination/dir/of/mp3s"
find -type f -name *.mp3 -print0 | while read -d  $'\0' file; do
        mkdir --parent "$end"/"$(mp3info -f -p %a "$file")"/"$(mp3info -f -p %l "$file")"
        mv "$file" "$end"/"$(mp3info -f -p %a "$file")"/"$(mp3info -f -p %l "$file")"/"$(mp3info -f -p %n "$file")"_"$(mp3info -f -p %t "$file")".mp3
done

The small program mp3info is used to extract id3 tags from the files. (Fortunately they are entered for almost all files). I am not the greatest bash-hacker in the world, so there might be a better way to do this. But I have tested this, and it works, and is quite fast.

If you know of a better way to do this, please comment. I would love to learn.