#bash scripts

Tip of the day?Seems to be turning into script of the day.Yes another script. This time I wanted a script to rename file, file.txt to file.txt.old or  file,txt.new to file.txt. Here’s the script to do this.

#!/bin/bash # Rename files depending on input # Check input is valid i.e. one argument either old or new if [ $# -ne 1 ] then echo "Usage: $0 new | old" exit 1 else if [[ $1 != "new" && $1 != "old" ]] then echo "Usage: $0 new | old" exit 1 fi fi TYPE=$1 # backup file to file.old if [ $TYPE = "old" ] then find . -name "*.txt" | while read TXTFILE do mv $TXTFILE ${TXTFILE}.old done fi # Rename file.new to file if [ $TYPE = "new" ] then find . -name "*.new" | while read NEWFILE do NEWNAME=`echo $NEWFILE | cut -d "." -f1-3` mv $NEWFILE $NEWNAME done fi

The script renames the file depending on whether old or new is specified as an argument. The first part just checks if one argument is supplied and if it does, then whether it is old or new. If one of them is an argument, it’ll either copy or rename the file depending on the option.

So, in essence, an example of checking input then doing a simple copy/rename,

I frequently use ImageMagick to convert screencaps (themself extracted using ffmpeg) into GIF animation.

The command for ImageMagick is nothing short of a veeery convoluted and hairy gobbledegook. For example:

convert -verbose -delay 12 *.jpg -resize 540x540 -ordered-dither o8x8,6 \( -clone -4 -set delay 18 \) -swap -5 -delete -1 \( -clone -3 -set delay 24 \) -swap -4 -delete -1 \( -clone -2 -set delay 30 \) -swap -3 -delete -1 \( -clone -1 -set delay 36 \) -swap -2 -delete -1 -layers Optimize vadercape_7_540.gif

Life’s too short, and such a convoluted command line is easy to make a mistake in.

So I wrote togif.sh to ease the job.

It runs perfectly in Cygwin, and I see no reason why it can’t run on Linux.

How to create custom commands in Unix/Linux

Few days ago one of my friend told me that the work on linux is so difficult, because he didn’t remember the complex commands of linux and every time when he want to do some debugging on their linux server he always need to google some commands first, so I’ve decided to write this post “How to create custom commands in Unix/Linux”.

There are many ways to do this, I’ve explained some of the…