How to take a screenshot on Macintosh OSX: http://guides.macrumors.com/Taking_Screenshots_in_Mac_OS_X. To delete your Internet history quickly in Firefox; use the Ctrl-Shift-Del keyboard combination. You will be presented with a dialog that allows you to select the time period to erase. Watch the original Star Wars movie in ASCII with this awesome website: http://asciimation.co.nz/. How to monitor …

To recall the last entered command on the Linux console, press the Ctrl-P key shortcut. You may also press the up arrow to recall the command, but the Ctrl-P shortcut is another good way to perform this feat. The CTRL-A shortcut will jump to the beginning of the line you are currently typing and CTRL-E …

A very obfuscated C program. typedef unsigned char t;t*F="%c",l[]="|\\/=_ \n](.\0(),*(.(=(}*.)[[*.",N=’\n’,* r;typedef(*H)();extern H Ar;Q(a){return(a|-a)>>31;}H S(c,a){return(H)(a&~c|(int )Ar&c);}extern t*ist;V(t*u){*u^=*u&2^(*u>>7)*185;}Z(t*u,t n){*u-=n;}e(t c,H h){ R(h,Q(* r^c));} I(){r=l +7-4*Q( getchar ()^*l); }R(H h, int c){Ar=S (c,h);- main() ;}P(){r ++;}z() { O(&N);} O(t*c){ printf( F,+*c); }T(){r= "This is not a function\n" ;}w(U){ U=Z(r,8 ); r-=~Q(* r/8-4); return 0; }M(){r= ist-68; } h(){t …

The Linux file-system tree explained. The standard Linux installation is laid out in various folders that each have a different role to play in the smooth running of a Linux distribution. The / folder is the root directory of a Linux directory structure. There are the . and .. entries above the / folder, but …

Apt errors. To deal with the message you get sometimes telling you that some packages have been kept back when you type sudo apt-get upgrade, just type sudo apt-get dist-upgrade. This will pull down the rest of the packages and fully upgrade your system. Uncompressing rar files. This is very easy with the unrar command. …