Scenario —————————————————————— You are maintaining several web-sites (site1.com, site2.org, etc…). Having just one web-site at localhost with all files (DocumentRoot) at /var/www/html is not an option for you. You need to be able to test all of them and to access them in a convenient way. Solution Setup apache with Virtual Hosts, give your sites […]
How can you see which code a module executes when your app calls an ioctl system call? Consider this situation: You app gets to the point where it executes an ioctl syscall and returns an error, e.g. if (ioctl(fd, STVMIX_IOC_DISCONNECTLAYERS, &STVMIX_Ioctl_DisconnectLayers) != 0) { /* IOCTL failed */ ErrorCode = ST_ERROR_BAD_PARAMETER; printf (” STVMIX_DisconnectLayers():Ioctl error […]
Most portable way to administer your printers under Linux is via CUPS’ web interface (CUPS stands for Common Unix Priniting System btw). Every cups server provides this interface, just point your browser to: http://localhost:631 The beauty of this solution: Being a web-bassed interface it available on every Linux distribution is completely independent of your desktop […]
Some versions of VLC have this problem: once you enable visualisations it can not be disabled. Yes, there is a radion button in the menu in Audio –> Visualisations which can be set to “Disable” but to no effect – on next start of VLC it displays the visualizations plug-in screen again. Even if you’re […]
How can you remove a mounted USB stick or USB HDD from the list of mounted devices? PROBLEM We have all done it – in a hurry you unplug a USB drive which was mounted in your Linux system without properly unmounting it and then it sits there in your list of mounts and you […]
Use imagemagick – this is exactly what it was designed for! 🙂 For example: – to resize all .jpeg files in the current directory to be 320 pixels wide, preserving the aspect ration, do this:  $ convert ‘*.jpeg[320x]’ resized%03d.jpeg – to shrink all .jpg files in the current directory to be 200 pixels wide, at […]
When setting up a dual-boot computer or even simply a new Windows computer: 1. Have a Linux Live CD/DVD/USB handy. It’s almost guaranteed that you will need it even if you’re only installing windows. 2. Save the MBR (“Master Boot Record”): Boot your Live linux and in the terminal type: sudo dd if=/dev/sda of=/some/path/your-mbr-backup-file bs=512 […]
This info copied from: https://vuanhduy.wordpress.com/2014/05/02/the-variants-of-gnu-makefile-assignment-operation/ The differences in =, :=, ?= and += when assigning a macro in Makefile. = operation If the variable does not have a value, the operation assign the value to it If the variable already had a value, it is replaced. This value will be expanded when the variable is […]
Getting DB_RUNRECOVERY error from yum/rpm, what can you do to fix it? The error messages look something like this: $ sudo yum install google-chrome-stable error: rpmdb: Thread/process 9662/3077695168 failed: Thread died in Berkeley DB library error: db4 error(-30974) from dbenv->failchk: DB_RUNRECOVERY: Fatal error, run database recovery error: cannot open Packages index using db4 – (-30974) […]
This is my current .emacs file. As you can see it’s got lots of goodies – indentation styles when editing code, jumping between parentheses/if/endif keywords, special key-mappings, custom search commands and much more 🙂