Command Line on Michael’s Domain

Taking an webcam image from the command line

Fri, 05 Apr 2024 00:00:00 +0000

There are probably not many use cases, but remote surveillance is an example, both in a malicious and legitimate context. Malware can take pictures of the unwitting user, and “Has anybody searched through my office after I forgot to close the door last Friday?”, respectively.

Deleting files with "illegal characters"

Fri, 08 Sep 2017 00:00:00 +0000

In the cross-platform environment of our university, at least three different OS connect to the smb shared group directories. Apparently Macs are able to save files with characters that are not allowed on other platforms and which cannot be easily deleted. Recently we had several files which ended with a ‘.’ (dot) or a ’ ’ (space), and we were not able to remove them via the GUI. In Windows 7, I managed via the command line with:delete "file." ordelete "file "I have, however, not found a way to so from my Ubuntu machine and it is annoying to boot into Windows merely to delete some files. Unfortunately, this became necessary because the Cloudberry backup system (which is running on Ubuntu) chokes on such files. I am looking into a new backup system for our lab’s computers since CrashPlan decided to discontinue support for non-business customers…

Batch renaming files on the command line

Tue, 28 Jun 2016 00:00:00 +0000

The default command line application for batch renaming files in Ubuntu 16.04 is called “rename”:rename 's/tk98i_/wt_tk98_/' *.tifIt uses Perl regular expressions with and the s/old/new/ syntax. The example above renames all files with the .tif extensions and replaces the th98i_ expression with wt_tk98_.Here are some more examples: http://tips.webdesign10.com/how-to-bulk-rename-files-in-linux-in-the-terminal

Reset MacOSX user passwords

Sun, 28 Apr 2013 00:00:00 +0000

Boot up with command key and S key pressed (Single user mode)
fsck -fy
mount -uw /
password username

Burning CDs from the command line: cdrdao

Wed, 23 May 2007 00:00:00 +0000

K3b seems to be the best GUI for burning CDs on Linux. But today it failed to burn an image file (bin/cue) and I don’t know why. So I used:cdrdao write --device /dev/cdrecorder --speed 8 filename.cue

Editing (resizing, format converting, compressing) images in the command line with ImageMagick (mogrify, convert)

Wed, 23 May 2007 00:00:00 +0000

Resize all tif images in the current directory:mogrify -resize 25% 25% *.tifResize all jpeg images in the current directory to a width of 614 pixels and keep the image ratio constant:mogrify -resize 614 *.jpgAs above, but resize the hight to 614 pixels:mogrify -resize x614 *.jpgConvert all bmp imgaes in the current directory into tiff images:mogrify -format tiff *.bmpCompress all tiff images in the current directory with ZIP compression:mogrify -compress ZIP *.tiffI tried to convert also pict files (from Macintosh), but without success, although the pict file format appears to be supported by Imagemagick. In order to make sure that ImageMagick knows that the file to convert is a pict file I used this command:convert pict:Photo0024.PICT tiff:Photo0002.tifThere is also a picttoppm utility in the netpbm package, but it was not anymore included in the version that Suse 9 uses; so I couldn’t check that out…Interestingly PixiePlus can display pict files, where does it take the routines from?If you have very large images, the default limits of ImageMagick are resulting in an error(e.g. mogrify-im6.q16: width or height exceeds limit) and you need to edit /etc/ImageMagick-6/policy.xml!

Command line rpm and SuSEconfig

Tue, 06 Mar 2007 00:00:00 +0000

After you run the rpm command from the command line, you always should run the SuSE config command in order to update the SuSE configuration files.