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How to open the web interface ports for Plesk on CentOS

After installing Parallels Plesk on a fresh server you may need to open ports 8443 and 8447 to access the web interface. These ports are not open by default. If your installation went fine but you can’t access Plesk in your browser via https://yourdomain.com:8443 then it’s likely that those ports aren’t open. Port 8443 is … Read more

How to list installed packages on CentOS

yum can help us here. This should do the trick: #yum list installed If you’re interested in a particular package, you can pipe a search string into grep and only list filtered results: #yum list installed | grep “yum” keyutils-libs.i686 1.4-4.el6 @anaconda-CentOS-201303020136.i386/6.4 yum.noarch 3.2.29-40.el6.centos yum-metadata-parser.i686 yum-plugin-fastestmirror.noarch The search string doesn’t even need to be in … Read more

How to find my own IP address in CentOS

Two commands come to the rescue: ip and ifconfig. Either does the trick: #ifconfig eth0 eth0 Link encap:Ethernet HWaddr 00:19:99:0D:D2:58 inet addr:87.106.181.234 Bcast:87.106.181.234 Mask:255.255.255.255 inet6 addr: fe80::219:99ff:fe0d:d258/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:14022830 errors:1 dropped:0 overruns:0 frame:1 TX packets:17605482 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:6842851425 (6.3 GiB) TX bytes:22015650673 (20.5 … Read more

How to convert a UIImage into NSData

You can store a UIImage (or an NSImage on Mac) as raw data. This can be useful if you’d like to save this in Core Data. Here’s how you convert a UIImage into NSData: NSData *imageData = UIImagePNGRepresentation(yourImage); To convert NSData back to a UIImage, you can do this: UIImage *image = [[UIImage alloc]initWithData:yourData]; The […]

How to fix Core Data error: “Receiver type xxx for instance message is a forward declaration”

Core Data is great. But when you add it to an existing project Xcode throws some random error messages at you that make you doubt your sanity. Again. Legitimately copied and pasted code from Apple’s own templates generates totally useless errors such as Receiver type ‘NSManagedObjectContext’ for instance message is a forward declaration. This isn’t […]

How to add 64bit support to your iOS apps

Apple’s new A7 processors support 64bit under iOS 7 – but only if your app is specifically compiled for 64bit. Ideally you want to compile once and use 64bit if the architecture supports, and if not use 32bit for devices that have A4 – A6x processors. Since Xcode 5.0.2 you can do this, and here’s […]