Command Line

Apple has enabled a new default security oriented featured called System Integrity Protection, often called rootless or SIP, in Mac OS from versions 10.11 onward. The SIP / rootless feature is aimed at preventing Mac OS X compromise by malicious code, whether intentionally or accidentally, and essentially what SIP does is lock down specific system … Read More

Mac based web developers are probably familiar with manually starting and stopping the Apache web server in OS X through the command line by now, but if you want Apache to start itself automatically upon boot and reboot of a Mac, you’ll want to go a step further and use launchctl. By doing so, webdevs … Read More

Ever wished you could set a Macs wallpaper image from the command line in OS X? As a matter of fact, you can change the desktop background picture from the terminal, which can be useful for a variety of situations ranging from inclusion in a setup script, to remote management, automating, or whatever else you … Read More

Typically if you’re looking to determine the file type and encoding of an item, you can simply look at the file in the Mac Finder, check the file name extension, Get Info about the file, or even open it to quickly find out what the file is. Of course, that’s limited to the user friendly … Read More

A symbolic link created at the command line allows a linked object in the file system to point to an original object in a different location. In this way, symbolic links behave much like an alias does in the Mac OS X GUI, except that the linking and reference between files or folders is done … Read More

If you need to release and renew DHCP from the command line on a Mac, the helpful ipconfig utility is able to do so quickly. Do keep in mind that for most Mac OS X users, renewing a DHCP lease from the Mac System Preferences is the best approach because it’s user friendly and just … Read More

At the command line, environmental variables are defined for the current shell and become inherited by any running command or process. They can determine anything from the default shell, the PATH, the users home directory, to the terminal emulation type, current working directory, where a history file is located, language and localization settings, and going … Read More

Given the complexity of some wi-fi network passwords combined with the general infrequency of entering them and that they’re typically saved on use, it’s not terribly unusual to forget what a specific routers wireless password is. Fortunately, if you’re on a Mac, there are a few ways to go about finding those lost or forgotten … Read More

Typically if you want to have an application launch approved by the GateKeeper feature on a Mac, you right-click on the unidentified developers application and choose “Open”, or go through System Preferences to bypass Gatekeeper that way. Another option is to manually add application approvals and exceptions to Gatekeeper by turning to the command line … Read More

Kernel extensions, called kext for short, are modules of code that are loaded directly into the kernel space of Mac OS X, able to run at a low-level to perform a variety of tasks. Most kexts are part of the core Mac OS X system software, typically hardware device drivers, but some third party apps … Read More

If you have downloaded an ISO image of another operating system, say Ubuntu Linux or Windows 10, and you wish to turn that ISO image file into a bootable USB installer drive using a USB flash drive or USB key, you’ll find the most reliable way to copy or ‘burn’ the ISO to that target … Read More

There are some situations where knowing exactly what wireless networks a Mac has connected to and when that connection was last established can be helpful. We’ll demonstrate how to uncover a comprehensive listing of specifics about previously joined wi-fi networks on a Mac, which will include the last connection date and time (to the second!), … Read More

Advanced Mac users may find it useful to know that DNS servers in OS X can be set from the command line, without having to turn to the System Preferences Network control panel. While the GUI Network control panel is undeniably the easiest approach for most Mac users, the command line method offers benefits for … Read More

Though most Mac users will want to keep Gatekeeper enabled for security purposes, some advanced users find that Gatekeeper is overly zealous in preventing third party apps from being used in macOS and Mac OS X. While it’s easy to turn off Gatekeeper through the System Preferences on a Mac, another option is to disable … Read More

Whether performing a packet trace or sniffing and capturing packets from a network, the result is usually the creation of a .cap capture file. That .cap, pcap, or wcap packet capture file is created regardless of what you’re using to sniff a network, a fairly common task among network administrators and security professionals. Perhaps the … Read More

If you use VirtualBox to run guest operating systems within a virtual machine on the Mac, like Windows 10 or Ubuntu Linux, you may find yourself needing to resize the virtual disk size where the OS resides. This is often the case when you inadequately estimate how much space is required for properly installing in … Read More

Each release of MacOS or Mac OS X has a unique build number assigned to it to represent the changes found in that version of system software, often these changes are minor and incremental, but with major Mac OS X releases the build numbers can change significantly. Though average Mac users won’t need to know … Read More

All domains are associated with an IP address, whether it’s for a website, mail server, or whatever else. While using nslookup offers a simple way to get DNS information and an IP for a specific website or domain, if you want a significantly more detailed retrieval, you can use the host command instead. The host … Read More