Obtain the number of CPUs / cores in Linux / bash

grep -c ^processor /proc/cpuinfo 

Src:http://stackoverflow.com/questions/6481005/obtain-the-number-of-cpus-cores-in-linux 

Inkscape - change the color of markers

How do I change the color of markers (e.g., arrow ends)?

By default, markers are black. You can change their color to match the color of the stroke of the object they are applied to by enabling an effect: Extensions > Modify Path > Color Markers to Match Stroke. 

http://wiki.inkscape.org/wiki/index.php/Frequently_asked_questions#How_do_I_change_the_color_of_markers_.28e.g..2C_arrow_ends.29.3F