How do I check if terminal is installed on Mac?

 UPDATE: I’ve written a free app that pretty much supercedes what I wrote in this post. DetectX 2 now has a system analyser that records and displays changes to your system configuration over time.

Ever wondered if a link you clicked sneakily downloaded and installed some unwanted software on your mac? Or have you suddenly found your mac behaving weirdly, a situation that is often a result of installing new software that conflicts with something else on the system, but can’t remember what you recently installed? In these sorts of scenarios, what you need to do is check your install logs.

I’ll tell you how to do that in a moment – in a number of ways – but first let’s just make a few notes. Firstly, chances are you’ll find more than one install log in your logs folder. The most recent one is simply called install.log, older ones will have a filename ending with .bz2, indicating a compressed file. Secondly, the reason you may have more than one install log is that OS X creates new install logs every time the log file gets to around 1MB in size. It then compresses and keeps the old logs, typically up to five logs prior to the current one.

Pro Tip No.1: if you’re a Terminal whizz and you want to change how many old logs are kept or at what size the log file gets turned over, you can edit the /etc/newsyslog.conf file, but be sure to read the man page for newsyslog first.

Typically, we’re only going to be interested in examining the most recent log file if troubleshooting new problems, but the process that I’m going to describe here can also be used to view the older logs, too. Apple buries the logs deep into parts of OS X that ordinary users typically don’t reach, but fortunately, there’s numerous ways to get at your install logs, and though some of them may be unfamiliar, none of them are particularly difficult or dangerous.

1. View only recently installed items
Open the Terminal.app (Utilities/Terminal.app) and copy and paste this command:

grep 'Installed' /private/var/log/install.log

This will return a list of every item successfully installed since the new log file was created. If there’s nothing of interest there, but you think there should be, then you’re going to need to see a bit more of the log file, and perhaps find out when it was ‘rotated’ or ‘turned over’ (i.e., the last time the system archived the install.log and created a new one).

2. View the entire install log
If you’d like to see the whole log for this reason, or perhaps you want to see whether something failed to install, it’s probably best having the log displayed in TextEdit rather than Terminal, so copy and paste this command into the Terminal window:

cat /private/var/log/install.log | open -f

You’ll see at the beginning of the file it’ll tell you when the file was turned over. Don’t forget you can use TextEdit’s search facility (Command-F) to search for particular instances or items you’re interested in finding. When you’re finished viewing this file, you can simply close TextEdit and discard it. It isn’t the actual log file, but rather a local copy of it.

3. Using Console
Alternatively,, if you don’t feel comfortable in Terminal, you can view all your install logs in the Console.app. You can open Console either through Finder by navigating to /Applications/Utilities/Console.app or just by typing ‘cons’ in either Spotlight or Launchpad. Once Console is open, scroll down the sidebar, looking for /var/log. Click the disclosure triangle if it’s not already pointing downwards and look for install.log. Click on that, and then in the filter bar in the main window, type installed (unlike the grep command I gave you above, this one is not case sensitive and will return both ‘Installed’ and ‘installed’).

examining an old, compressed install log

Notice in the screenshot above, I’m examining a turned over log, not the current one. As this particular install of Mountain Lion was only done on May 3rd, there’s only one turned over log file.

Pro Tip No.2: You can force the system to turn over all the log files, including install.log even if they haven’t reached their maximum size. As it says in the man page for newsyslog, this can be “useful for diagnosing system problems by providing you with fresh logs that contain only the problems.”

To force all log files to be turned over, simply enter sudo newsyslog -F into Terminal. Hit ‘return’ and supply your password, as always with the sudo command.

4. Using Finder
If Console is a bit too off-territory for you, there’s nothing wrong with viewing your logs in Finder and TextEdit. To do that, click on the Finder, then hit ‘shift-command-G’ on the keyboard (or click ‘Go’ in the menu bar and choose ‘Go to Folder’). Type or paste this into the dialogue box:

/var/log

and hit the ‘Go’ button.

Right-click on any of the logs you want to open and choose ‘open with’ from the contextual menu. Choose ‘TextEdit’ or your favourite plain text editor app. If none of your text editors show up in the menu, click ‘Other’ and change the ‘Enable’ menu to ‘All Applications’. You will now be able to choose TextEdit or some other editor if you have one. Note that unlike Step 2 above when we used a Terminal command to open a copy of the install log in TextEdit, here you are viewing the actual files rather than a copy of them. Although the log files are not important to the running of your system and can be deleted or altered without causing any consequences, they do provide useful records for troubleshooting so its always good practice to keep them in tact if you can.

And that, in a nutshell, is how you view your install logs! 

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Featured picture: Rectangleum by *Eccoton