Question

One tip or trick per answer.

My favorite is

open .

Opens the folder you're currently browsing in Finder.

Mac OS X specific answers only.

Answer 1

pbcopy and pbpaste:

# Copy output of command to clipboard
grep 'search term' largeFile.txt | pbcopy

# Abuse clipboard contents
pbpaste | sed 's/ /%20/g'

Answer 2

The say command invokes the system text-to-speech capabilities.

say "Hello there."

Answer 3

It's not built in but this is the most effective way to get my wife to stop using my laptop to read celebrity news for hours after 4-5 requests to get my macbook back:

echo 'The system is overheating and needs to go to sleep now.' | \
growlnotify -a 'Activity Monitor' 'OVERHEATED'; \
sleep 1; \
say 'Overheated system.'

Since it's almost always around 70c it's believable.

Answer 4

opensnoop is my new favorite utility. It uses DTrace to show you all of the files that are being accessed on your system, you need to execute it with superuser privileges

sudo opensnoop

You can also watch what a particular process opens by passing in the PID:

sudo opensnoop -p PID

Or watch a particular file to see who's opening it

sudo opensnoop -f /etc/passwd

Answer 5

(Assuming we're looking for Mac OS X specific tricks.)

I've got an alias to launch quicklook on a file from the command line:

$ type -a ql
ql is aliased to `qlmanage -p 2>/dev/null'
$ ql photo.jpg
Testing Quick Look preview with files:
    photo.jpg

Hit CtrlC to kill it and return to the prompt.

Answer 6

$ emacs -batch -l dunnet

Dead end
You are at a dead end of a dirt road.  The road goes to the east.
In the distance you can see that it will eventually fork off.  The
trees here are very tall royal palms, and they are spaced equidistant
from each other.
There is a shovel here.
>

Answer 7

With hdiutil you can easilly mount a disk image:

hdiutil mount ~/Desktop/lastest_webkit.dmg

Dismounting takes a bit more work:

hdiutil detach `df | grep WebKit | perl -pe 's@^/dev/([a-zA-Z0-9]+).*@$1@'`

Answer 8

history shows a list of the recent commands you've run — something like 500 or 600 commands. I frequently use history | grep something to find a command i've used recently.

Answer 9

diskutil is a very powerful command-line tool for working with disks and disk images. It's gotten me out of some binds. It's not too hard to use.

Answer 10

Although I can get around in vi, I use TextMate as my command line editor. You can also pipe things to it. For example ls|mate opens up TextMate with the current directly listing open in a text window.

Answer 11

mdfind to use spotlight from the command line - really really really handy! Finds things in every directory as well, so it's more useful when looking for files that are part of the system.

mdfind -live updates in real time, which again is incredibly handy.

Answer 12

Quickly check what is eating all your memory:

top -o vsize

And for your CPU

top -o cpu

Q to quit

Answer 13

!!

Runs the last command again. Great for tracking changes.

Answer 14

textutil is a very handy tool that can cross convert text between HTML, RTF(D), Word (including XML), OpenOffice.org Writer, and the webarchive format.

I use it, notably, in a service that converts the selected text to HTML, uploads it to a server then imports it into Instapaper.

Answer 15

http://github.com/joelthelion/autojump - "cd" that learns.

Answer 16

the most interesting pschotherapist you will ever talk to:

• Run emacs
• Press shift-esc, then x
• type doctor and press enter
• have fun :D

Answer 17

cd -

Will restore the previous directory you were in. Very handy if you accidentally type cd and flip to home.

Answer 18

I've recently been using net rpc shutdown --server=<servername> --username=<username> to shutdown my windows boxes.

Answer 19

cd - jumps back to the last directory you were in.