File and folder paths are given conventionally. Where a path starts with a slash /, that is assumed to be at the root level of the volume, so the path
/System/Library/Fonts
represents the Fonts folder inside the Library folder inside the System folder.
Where the path starts with a tilde ~, that starts the path in your current Home folder. So for the user Me
, the path
~/Library/Fonts
represents the Fonts folder inside the Library folder inside the Me folder inside the Users folder.
A path given without ~ or / at the front is relative to where we are already, so if I am writing about your Home folder Library,
Fonts/Microsoft
refers to the Microsoft folder inside the Fonts folder of that Home folder Library.
Articles here use fonts and styles to help make meaning clearer. Generally, commands which are typed into Terminal’s shell are set as code
, for example
ls -laO
and any output from them is set similarly. Paths, menu commands, dialog items, and other text may be set in bold, italic, or sometimes code
as needed to distinguish it from surrounding text.
Swift, AppleScript, and any other code written in a programming language is normally set in code
too. Where appropriate, I provide images of neatly formatted code as well as unformatted text versions, so that you can read the former more easily, but copy and paste from the latter, relying on your code editor to do the formatting.
Unless otherwise specified, you are welcome to make full use of code given here in any program which you develop. I post it here for that purpose.
There are special startup modes which you should be comfortable with:
- Safe Mode – engaged by holding the Shift key during startup – flushes various system caches and should disable all non-Apple extensions and other crud. This is detailed here.
- Recovery Mode – Command-R during startup – engages the recovery feature of recent (10.7 and later) versions of macOS / OS X, and is detailed here.
- Diagnostics or Hardware Test Mode – engaged by holding the D key during startup – runs Apple’s hardware test routines to determine if your Mac has a hardware issue. It is detailed here.
- Single User Mode – Command-S during startup – mounts the startup volume in read-only mode, and leaves you in Terminal’s command shell ready to perform serious surgery such as repairing your startup volume. In recent versions of macOS / OS X, this has become less useful, and has largely been replaced by Recovery Mode.
There is a full guide to startup key combinations here.
Key tools for analysing and diagnosing problems in OS X include:
- Console or Consolation – browse all logs back to the time that a problem occurred to look for clues as to what happened. Interpreting these logs may not be easy, but they usually give the best clues of the cause. Unfortunately crash logs, written out when an app actually crashes, are of much more limited value unless you are the developer of the app. In El Capitan and earlier versions of OS X, the bundled Console is ideal for accessing the logs. In Sierra, the log system has changed and Console cannot readily access log entries which have already been made; for that you will need my free app Consolation, detailed here, with further explanation here.
- Activity Monitor – this can tell you what is consuming all the CPU time, network bandwidth, etc. However many people use it to convince themselves that they have insufficient memory. macOS uses memory very efficiently, and tries to fill real RAM rather than leave things cached out to disk. Thus interpreting memory statistics from here is fraught with difficulty and can confuse.
- Disk Utility – with the advent of System Integrity Protection (SIP) in El Capitan, repairing permissions is no longer the panacea that it used to be, but ensuring that your startup disk is healthy is a good first step in resolving many problems.
- Terminal – most users are too terrified to venture into this key utility. Provided that you are meticulously careful and cautious, it is perfectly safe. However you should always check through each command that you write before pressing return to start it. Whilst you are doing that, follow the old adage and ‘check twice, run once’.
- KnockKnock and other security tools from Objective-See – these allow you to inspect persistent processes running on your Mac, and much more. They are all free.
- An anti-virus checker such as Malwarebytes – although true malware remains unusual, it is easy to have unwanted software and adware installed, which can cause problems. Running a quick check for the presence of malware can eliminate that as a cause.
macOS / OS X still runs best when it has two key ingredients:
- ample real memory,
- ample contiguous (not fragmented) free disk space on its startup volume.
Checking the latter is no longer as free and easy as it once was.
If the preference settings in an app do not seem to be working, it is possible that the Property List (.plist) storing them has become munged. Quit the app, locate its settings file (which can be tricky at times), and move it to a folder in ~/Documents. Then open the app and set its preferences up again; they should now stick properly.
There is an extensive list of preference file locations available here for macOS Sierra, and here for OS X El Capitan.
I maintain two special listings of articles and other items of direct relevance to Macs:
- Mac probs (problems) contains a breakdown of key articles by subject area. The first sections are those about dealing with common problems, and there are many more specialist topics later.
- Downloads contains the current versions of my free software products such as Consolation. Articles may still contain links to older versions if you want them, but the current release will be available from Downloads.