If you get this error message when trying to update the system (see example below) or just pinging an external host … $> sudo pacman -Syu :: Synchronizing package databases… error: failed retrieving file ‘core.db’ from mirror.archlinuxarm.org : Could not resolve host: mirror.archlinuxarm.org error: failed to update core (download library error) error: failed retrieving file ‘extra.db’ […]
If you want to see, what a process does, you can use: $> strace -p PROCESSID This will show you all actions of the process in realtime. To get a process id you can use the ps-command.
$> ps waux –sort=-pcpu If you piped the result into the head command, you can limit the result to the n entries with the highest CPU usage. $> ps waux –sort=-pcpu | head -n 10 In this example you will see the ten most CPU-consuming processes on the machine. The ‘–‘ before pcpu results in […]
Therefore we use wget: wget -O outputfile.txt –user sheldon –ask-password https://ask-sheldon.com/genius-stuff.html # f.e. REST wget –http-user USER –http-password PASSWOR http://ask-sheldon.com/import.txt # HTACCESS protection If you let -O param out the output will be stored under its original name.
To delete all content from current position to the end of file on bash, you can take the following steps: Open file in vi or vim $> vi fiele $> # or $> vim file Switch to visual block mode Ctrl+v Press G (Shift+g) Mark text to delete with arrow keys top and down or just press […]
On Debian based Linux distributions you can get the MAC address of the respective network adapter from the filesystem like shown below: $> cat /sys/class/net/wlan0/address # WLAN adapter $> 81:82:83:4:85:86 $> cat /sys/class/net/eth0/address # LAN adapter $> 1a:1b:1c:1d:1e:1f As you can see, all adapters have their own folder under /sys/class/net/ that contains  a address file with the corresponding MAC […]
Sometimes its necessary that your machine gets a static IP-address. For example if you want to run a server or a other service on that machine. On Debian based machines you can do this by: Edit /etc/network/interfaces (f.e.: with nano) auto lo iface lo inet loopback auto eth0 iface eth0 inet static address 192.168.88.6 netmask 255.255.255.0 […]
To shred files or partitions securely: $> shred -vun <loops> <File1> <File2> $> shred -vzn <loops> <Device> loop is the count of the loop beginning with 0 (3 means 4-times)!!! You can get the partition table as described in List of partitions or List, partitioning and format drives. If you want to shred a directory recursively, you […]
List all devices: $> sudo fdisk -l That will give you an overview about all your drives like that: Disk /dev/sda: 256.1 GB, 256060514304 bytes 255 heads, 63 sectors/track, 31130 cylinders, total 500118192 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): […]
You can get a sorted list of directory items with a combination of the ls- and sort- command: $> ls -al | sort -nk9,9 With k you can define the column(s) (here 9 till 9) to use for sorting. The parameter n results in a numeric sorting.
