Install Ubuntu truncate command to Mac OS X 10.7

Update:

As of March 2015 truncate is no longer available in Homebrew as a standalone formula.

As truncate is part of GNU Coreutils you should install it on OS X with the following command:

> brew install coreutils

After installation truncate will be available under the name gtruncate. Note that all programs from Coreutils will be available with the prefix g.

This shouldn't really be in Server Fault, probably Super User or Ask Different, but you can install a lot of binaries by using homebrew, found here:

http://mxcl.github.com/homebrew/

Firstly you'll need to install command line tools for Xcode, which will probably require you to purchase it if you havn't already.

Once you've done this, run:

ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"

To install homebrew, then when it's installed, run:

brew install truncate

When truncate is not available you can often use dd instead. Eg.

Make a file full of zeros:

dd if=/dev/zero of=/tmp/youroutputfile bs=1m count=50

Truncate an existing file:

dd if=yourinputfile of=/tmp/youroutputfile bs=1k count=1

Note: the OS X dd uses lower case unit letters where GNU dd uses upper case.