Adding colorized ls output to the Terminal in Mac OS X is a good way to make navigating around the command line a bit easier on the eyes. This makes different items show up in different colors, including directories, files, executables, and symbolic links.
An alternative to checking a SHA1 hash with shasum is to use openssl. Yes, the same openssl utility used to encrypt files can be used to verify the validity of files. The syntax is quite similar to the shasum command, but you do need to specify ‘sha1’ as the specific algorithm like so:
SHA hashing is frequently used with distribution control systems to determine revisions and to check data integrity by detecting file corruption or tampering. For common usage, a SHA checksum provides a string that can be used to verify a file been transferred as intended. If SHA checksums match, the files integrity has been maintained. This … Read More
Spotlight is generally very good at keeping a valid index of a drives contents up to date, but if you’ve recently restored a drive or had to delete the Spotlight index for one reason or another, you may need to reindex the drive manually. This is easy from the Spotlight control panel, and can also … Read More
It’s easy to lose track of all the defaults commands used to perform tweaks to Mac OS X, but with the help of the history command it’s easy to list every defaults write and accompanying defaults delete commands ever used on a Mac. Launch the Terminal to get started. See All Defaults Commands Executed To … Read More
Need to quickly encrypt a file from the command line? With OpenSSL, you can encrypt and decrypt files very easily. For the purpose of this walkthrough, we’ll use des3 encryption, which in simple terms means a complex encryption algorithm is applied three times to each data block, making it difficult to crack through brute force … Read More
The default behavior for most command line tools is to show sizes in bytes, for tiny text files that is fine but when you start working with larger items this becomes difficult to read and interpret. The solutions is fairly simple, pass a “human readable” flag with the command, which will convert bytes to a … Read More
Modern versions of Mac OS X include a great tool called tmutil that lets you interact with with Time Machine from the command line. It’s a powerful utility that has a ton of options, and we’ve used it before to disable local snapshots, but for the purposes here we are going to use tmutil to … Read More
You can monitor disk activity in Mac OS X by using the Activity Monitor app or several command line tools. Activity Monitor is the easiest and most user friendly, but the Terminal options allow further information to be retrieved.
Using the lsof command, we can find out exactly what process or application is using a specified file at that given moment. This is similar to the opensnoop command, but rather than watching the changes to a file over time, lsof can give us a snapshot of this very moment, which can be helpful for … Read More
Advanced Mac OS X users may find it useful to know that KEXT (kernel extensions) can be manually installed. The process of installing kexts manually into OS X is not too difficult if you’re comfortable with the command line, but it is a multi-step process of copying the appropriate .kext file to the appropriate kernel … Read More
Creating a password protected zip file is easy in Mac OS X and does not require any add-ons or downloads. Instead, use the zip utility that is bundled with all Macs. This offers a simple way to protect a zip archive file from unwanted viewing access, as when a user attempts to decompress the contents … Read More
The Mac OS X Terminal includes a great feature that lets you quickly access new manual pages from any existing Terminal window.
Go2Shell is a free Finder toolbar add-on that creates a new Terminal window from the current directory of any desktop folder in Mac OS X with a click of a button. This is similar to the services option that can be added to the right-click contextual menu, but Go2Shell is faster due to resting in … Read More
A helpful command line tool called hdiutil is included in Mac OS X that allows disk image files (.dmg extension) to be mounted directly from the Terminal, without the need of using the GUI. Using hdiutil for such a task is helpful for scripting or remote connections through SSH.
Completely disabling and reenabling Spotlight in Mac OS X Lion, OS X Mountain Lion, and OS X Mavericks can be done with the help of the Terminal. The following command unloads the Spotlight mds agent from launchd, thereby preventing the daemon from running or indexing any drives entirely. Open up the Terminal (found in /Applications/Utilities/) … Read More
If you shuffle between the Terminal and the Mac OS X desktop often, you’ll get good use out of a Services feature which gives the ability to create a new Terminal window (or tab) from a selected folder within the Finder. You have to enable the Service inside System Prefs beforehand though:
Command line users who wish to add an additional layer of security to their keyboarding within Terminal app can find a helpful privacy feature built into the Mac client. Whether aiming for generally increasing security, if using a public Mac, or are simply concerned about things like keyloggers or any other potentially unauthorized access to … Read More
