Useful Commands 1

This page is mainly an aide-mémoire for me but some of these may be useful for others. Add suggestions for improvements in the comments.

These should all run on bash, additional requirements are noted.

Create a set of test images

This creates a set of images with the numbers 1 to 10 in the middle. Useful for creating a set of images for further scripting tests. Requires ImageMagick.

Single line version

for i in {1..10}; do convert -size 800x600 xc:#ffffccff -fill black -pointsize 80 -draw "text 400,300 '$i'" test-img-$i.jpg; done

Script version

#!/bin/bash
for i in {1..10}
	do
		convert -size 800x600 xc:#ffffccff -fill black -pointsize 80 -draw "text 400,300 '$i'" test-img-$i.jpg
	done

List directories

Updated 2014-01-03 to make it compatible with spaces in directory names

This lists subdirectories of the current directory while stripping the closing / making it useful where directory names need to be used as a variable.

#!/bin/bash
ls -d */ | while read line
	 do
	 	dir=${line%*/}
	 	echo $dir
	 done

Strip spaces

Replaces spaces in filenames with underscores for all files (non-hidden files) in the current directory

#!/bin/bash
ls | while read -r FILE
	do
		mv -v "$FILE" `echo $FILE | tr ' ' '_' `
	done

Unzip archives to individual subdirectoies

Unzips all zip archives in the current directory creating a subfolder for each that is named after the archive (minus the zip extension)

ls *.zip | while read file
	do
		unzip "$file" -d ./"${file/.zip/}"
	done

Bulk renaming

Examples are image renaming but will work with others. Affects all files in the current directory.

Add text between filename and extension. Renames filename.png to filename-text.png

ls *.png | while read file
	do
		mv "$file" "${file/.png/}"-text.png
	done

Add text before filename. Renames filename.png to text-filename.png

ls *.png | while read file
	do
		mv "$file" text-"$file"
	done

Added 2014-01-04

Batch conversion of SVG files

These convert all SVG files in a directory to EPS or PNG for use with $LaTeX$ etc. This method requires Inkscape.

EPS Conversion

#!/bin/bash

ls *.svg | while read file
	do
		inkscape "$file" --export-eps="${file/.svg/}.eps"
	done

PNG Conversion

This script takes an additional argument to determine the resolution (DPI) of the output files. Personally I have it saved in my PATH as svg2png and run as svg2png <DPI>. E.g. “svg2png 300” will export 300 DPI PNG files.

#!/bin/bash

ls *.svg | while read file
	do
		inkscape "$file" -d $1 -e "${file/.svg/}.png"
	done