Very cool Macintosh OSX trick and some useful and interesting Linux commands.
Hey mac lovers! Did you know that Apple left stuff from the old Apple II in modern Macs? Yes, it’s true! and you can test it right now! This command makes your Mac play music made for the good ol’ Apple II (chiptunes if you ever heard the term 🙂 Just open the Apple Terminal (you can find it at Finder → Utilities → Terminal) and type this:
echo "appleIIchptn" && for i in *; do mv "$i" chiptune_play; done
The code activates the old Apple II chiptune code left by Apple Engineers in Macintosh OSX and then plays a well known tune, guess which one 😉
How to search your home directory for certain files. The find command is very useful for searching your computer for various files.
john@adeptus-mechanicus ~ $ find /home/$LOGNAME -name "*.avi" /home/john/Azureus Downloads/[ www.Torrenting.com ] - The.Hobbit.2012.DVDSCR.XVID-NYDIC/The.Hobbit.2012.DVDSCR.XVID-NYDIC.avi /home/john/Azureus Downloads/[ www.Torrenting.com ] - The.Hobbit.2012.DVDSCR.XVID-NYDIC/sample/sample.avi
This is how you can use the find command to find certain files in a directory and then delete them.
john@adeptus-mechanicus ~/Documents $ find /home/$LOGNAME/Documents -name "*.o" -delete
This command will find all files in the /tmp directory that are named ‘core’ and delete them.
john@adeptus-mechanicus ~/Documents $ find /tmp -name core -type f -print | xargs /bin/rm -f find: `/tmp/kde-kdm': Permission denied find: `/tmp/ksocket-kdm': Permission denied find: `/tmp/pulse-PKdhtXMmr18n': Permission denied john@adeptus-mechanicus ~/Documents $ sudo find /tmp -name core -type f -print | xargs /bin/rm -f [sudo] password for john: john@adeptus-mechanicus ~/Documents $
The apropos command is used to search manual pages for a certain string. This is how it works.
john@adeptus-mechanicus ~/Documents $ apropos "unix" AF_UNIX (7) - Sockets for local interprocess communication authunix_create (3) - library routines for remote procedure calls authunix_create_default (3) - library routines for remote procedure calls b2m (1) - This program converts a babyl mailbox to a standard unix mailbox. b2m.xemacs21 (1) - This program converts a babyl mailbox to a standard unix mailbox. boom (6) - PrBoom, a version of Doom for Unix, Linux and Windows systems brltty (1) - refreshable braille display driver for Linux/Unix doom (6) - PrBoom, a version of Doom for Unix, Linux and Windows systems git-mailsplit (1) - Simple UNIX mbox splitter program IPC::Run (3pm) - system() and background procs w/ piping, redirs, ptys (Unix, Win32) irw (1) - sends data from Unix domain socket to stdout lircd (8) - LIRC daemon decodes infrared signals and provides them on a Unix domain socket. mc (1) - Visual shell for Unix-like systems. mcdiff (1) - Visual shell for Unix-like systems. mcopy (1) - copy MSDOS files to/from Unix mtools (1) - utilities to access DOS disks in Unix. Net::DNS::Resolver::UNIX (3pm) - UNIX Resolver Class pam_unix (8) - Module for traditional password authentication pbmtoplot (1) - convert a portable bitmap into a Unix plot(5) file PF_UNIX (7) - Sockets for local interprocess communication prboom (6) - PrBoom, a version of Doom for Unix, Linux and Windows systems samba (7) - A Windows SMB/CIFS fileserver for UNIX smbtar (1) - shell script for backing up SMB/CIFS shares directly to UNIX tape drives standards (7) - C and UNIX Standards unix (7) - Sockets for local interprocess communication unix_chkpwd (8) - Helper binary that verifies the password of the current user unix_update (8) - Helper binary that updates the password of a given user wine (1) - run Windows programs on Unix winemaker (1) - generate a build infrastructure for compiling Windows programs on Unix winepath (1) - Tool to convert Unix paths to/from Win32 paths xdr_authunix_parms (3) - library routines for remote procedure calls
The apropos command relies upon the mandb command to update the database of all installed manual pages. This is taken care of automatically by a modern Linux system; but you can run it manually to see if everything is up to date.
john@adeptus-mechanicus ~/Documents $ mandb 0 man subdirectories contained newer manual pages. 0 manual pages were added. 0 stray cats were added. 0 old database entries were purged.