OneAndOneIs2

Linux is my favourite OS, and has been since I discovered it back in the 90's. I actually don't like the direction it's taken since then - Ubuntu et al are very helpful when you just want to get up & running quickly, but most of the Linux GUIs suck massively. Unity, Gnome 3, KDE 4 are just a few of the most recent examples of the problem.

Fortunately, the command line is where I prefer to be, and this remains an area of unparalleled excellence. There's a lot of little things that the CLI can do to make life easier, many of which aren't well known. So here's a bunch of things I find worth knowing:

• mkdir -p a/b/c/d
  - create subdirectories all at once
• tar:
  x - extract
  c - create
  v - verbosely
  z - zipped
  j - bzipped
  f - file
  t - list
  e.g.s
  tar -cf archive.tar foo bar
  - creates archive.tar containing files 'foo' and 'bar'
  tar -tvf archive.tar
  - lists contents of archive.tar
  tar -xvzf archive.tgz
  - extracts verbosely the zipped archive
• find . -perm g+w
• find . ! -perm g+w
  - find files with/without specified permissions
• pgrep -u djh -l
  - list all processes for 'djh'
• pstree
  - list all processes in their tree
• chmod g+s dir/
  - all files created in dir/ will have same group as the directory does
• mutt -a file
  - email the file from the CLI
• du -hs *
• du -h --max-depth=1
  - sizes of all dirs in current directory
• !!
  - replace with previous command, useful for 'sudo !!'
• Ctrl-r
  - interactive search back through history
• !$
  - Use previous command's argument, e.g.:
  mkdir new
  cd !$
• PATH=~bin/:$PATH
  - Append directory to your path
• function name {
  command $1 | command2
  }
  - How to define a bash function
• mtr
  - clever traceroute
• sar -q
  - load averages
• lsof -p `pidof X` | wc -l
  - get all processes run by X
• netstat -an --unix | grep X11-unix
  - Get all network connections to X11