Monday 9 February 2009

Miscellaneous stuff of use

The documentation on the use of 'wget' is a little sketchy on one of its most powerful uses - automatically downloading loads of files from internet servers. Let's say you need the 1000 tiff files sitting at http://www.server.com/hypothetical_directory

Apparently wildcards are out, such as:

$ wget http://www.server.com/hypothetical_directory/*.tiff

because html does not support 'globbing'. So here's the solution:

$ wget -r -1l --no-parent -A.tiff http://www.server.com/hypothetical_directory

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Another thing I've needed to do recently is get ALL the metadata from an image file - you wouldn't believe how much information is recorded - channel statistics, histogram of shades, date/time, camera make, resolution - you name it, its recorded. It's a wonderful thing about using images for your research as well - you can keep track of all your metadata in the data files! Right, well I discovered that no amount of 'right-clicking' on the image - in any operating system - will tell you everything you need to know. The suitable command is:

$ identify -verbose myimage.jpg

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Finally, for now, a couple of sites that will help you if you need to make a purchase of hardware for your linux machine:

This one keeps a database of usb-devices which are known to be linux-friendly, and the following two help you out when choosing a compatible printer and scanner: here and here.

Keep on truckin'

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