Linux Tips & Tricks - image processing from the command line
The first time you have to process a lot of images in the same way or need to process them from a script, you'll be thrilled to learn about the wealth of command line tools available. Here is a small sampling of those tools to get you started.
https://opensource.com/life/16/9/command-line-image-tools-linux
Friday, 23 September 2016
Thursday, 22 September 2016
Linux Tips & Tricks - using the tar command
Linux Tips & Tricks - using the tar command
tar is one of the core administration tools of the *NIX world, it's been around forever and it's still highly useful today.
Here's a link to get you started using this powerful command-line tool.
#Linux #tar #sysadmin
http://www.linuxtechi.com/17-tar-command-examples-in-linux/
tar is one of the core administration tools of the *NIX world, it's been around forever and it's still highly useful today.
Here's a link to get you started using this powerful command-line tool.
#Linux #tar #sysadmin
http://www.linuxtechi.com/17-tar-command-examples-in-linux/
Linux Tips & Tricks - Hardware Encryption Acceleration
Linux Tips & Tricks - Hardware Encryption Acceleration
Does I has it?
Many systems and CPU's have built in encryption acceleration hardware. To find out if your system includes such hardware and how fast it is, run the following commands and compare the output. If your system has working hw acceleration, the line with -evp in it will return higher rates.
$ openssl speed aes-256-cbc
$ openssl speed -evp aes-256-cbc
For example, here's the relevant portions of the above output from one of my systems.
type 16 bytes 64 bytes 256 bytes 1024 bytes 8192 bytes
aes-256 cbc 68577.43k 72631.80k 73771.43k 74353.36k 74506.10k
type 16 bytes 64 bytes 256 bytes 1024 bytes 8192 bytes
aes-256-cbc 351297.11k 383059.63k 418126.17k 429977.26k 432078.85k
As you can see, the system is roughly 6 times faster with hw acceleration at processing 8k AES-256-CBC packets.
To just see what acceleration engines your system supports, type (with sample output):
# sort -u /proc/crypto | grep module
module : aesni_intel
module : aes_x86_64
module : crc32c_intel
module : crc32_pclmul
module : crct10dif_pclmul
module : kernel
To do a full encryption benchmark run on your system, type:
# openssl speed
#Linux #Encryption
Does I has it?
Many systems and CPU's have built in encryption acceleration hardware. To find out if your system includes such hardware and how fast it is, run the following commands and compare the output. If your system has working hw acceleration, the line with -evp in it will return higher rates.
$ openssl speed aes-256-cbc
$ openssl speed -evp aes-256-cbc
For example, here's the relevant portions of the above output from one of my systems.
type 16 bytes 64 bytes 256 bytes 1024 bytes 8192 bytes
aes-256 cbc 68577.43k 72631.80k 73771.43k 74353.36k 74506.10k
type 16 bytes 64 bytes 256 bytes 1024 bytes 8192 bytes
aes-256-cbc 351297.11k 383059.63k 418126.17k 429977.26k 432078.85k
As you can see, the system is roughly 6 times faster with hw acceleration at processing 8k AES-256-CBC packets.
To just see what acceleration engines your system supports, type (with sample output):
# sort -u /proc/crypto | grep module
module : aesni_intel
module : aes_x86_64
module : crc32c_intel
module : crc32_pclmul
module : crct10dif_pclmul
module : kernel
To do a full encryption benchmark run on your system, type:
# openssl speed
#Linux #Encryption
Tuesday, 6 September 2016
Accessing Google Drive from the Linux command line
Accessing Google Drive from the Linux command line
As much as we love Google, sometimes they suck too. Like for example, the fact that they've never produced an official Linux client for Google Drive really sucks.
However, Linux users are innovative and have come up with several different workaround solutions. Here's a popular one.
#Linux #Google #Drive
Google Google for Work
https://www.howtoforge.com/tutorial/how-to-access-google-drive-from-linux-gdrive/
As much as we love Google, sometimes they suck too. Like for example, the fact that they've never produced an official Linux client for Google Drive really sucks.
However, Linux users are innovative and have come up with several different workaround solutions. Here's a popular one.
#Linux #Google #Drive
Google Google for Work
https://www.howtoforge.com/tutorial/how-to-access-google-drive-from-linux-gdrive/
Sunday, 28 August 2016
Linux Tips & Tricks:
Linux Tips & Tricks:
Surviving systemd - "Where the hell are my logs?!"
At some point even casual Linux users are going to want to have a look at their system logs for one reason or another. It's an important part of many diagnostic processes. However, most of the how to's out there on the Internet are geared towards using the UNIX style system logs that Linux used for decades until it was struck with the plague that is systemd. If your system uses systemd, and these days nearly all do, then all of your nice, easily readable and grep'able text logs are gone! What to do. Well, those logs have nearly all been replaced by a binary journal that systemd keeps in a database. To access them you'll need to learn to use journalctl which is systemd's front end to the log database. Here's a nice tutorial to get you started on the basics of using it.
For the impatient, you can type the following to see what's been logged since yesterday. Be prepared for a deluge.
From a root shell:
journalctl --since yesterday
(Note the ^ double dash)
#Linux #systemd #Logs #sysadmin
https://www.digitalocean.com/community/tutorials/how-to-use-journalctl-to-view-and-manipulate-systemd-logs
Surviving systemd - "Where the hell are my logs?!"
At some point even casual Linux users are going to want to have a look at their system logs for one reason or another. It's an important part of many diagnostic processes. However, most of the how to's out there on the Internet are geared towards using the UNIX style system logs that Linux used for decades until it was struck with the plague that is systemd. If your system uses systemd, and these days nearly all do, then all of your nice, easily readable and grep'able text logs are gone! What to do. Well, those logs have nearly all been replaced by a binary journal that systemd keeps in a database. To access them you'll need to learn to use journalctl which is systemd's front end to the log database. Here's a nice tutorial to get you started on the basics of using it.
For the impatient, you can type the following to see what's been logged since yesterday. Be prepared for a deluge.
From a root shell:
journalctl --since yesterday
(Note the ^ double dash)
#Linux #systemd #Logs #sysadmin
https://www.digitalocean.com/community/tutorials/how-to-use-journalctl-to-view-and-manipulate-systemd-logs
Monday, 22 August 2016
Linux Tips & Tricks - Bash shell pitfalls
Linux Tips & Tricks - Bash shell pitfalls
In my ongoing quest to get people to either start using the command line, or use it more effectively, here's a great little resource for using the most common Linux command shell.
#sysadmin #Linux #CommandLine #bash
Via Carlos F. Lange
http://mywiki.wooledge.org/BashPitfalls
In my ongoing quest to get people to either start using the command line, or use it more effectively, here's a great little resource for using the most common Linux command shell.
#sysadmin #Linux #CommandLine #bash
Via Carlos F. Lange
http://mywiki.wooledge.org/BashPitfalls
Monday, 25 July 2016
Split terminal windows with Terminator for Linux
Split terminal windows with Terminator for Linux
While I personally prefer a tabbed style terminal emulator, I can see the appeal of this setup, especially if you live in the CLI.
NOTE to OpenSUSE users
If you are using Leap 42.1 or higher, ignore the instructions at the link and just type "zypper in terminator" from a root shell, or find the terminator package in YaST2's software manager.
#Linux #CommandLine
http://www.linuxandubuntu.com/home/terminator-a-linux-terminal-emulator-with-multiple-terminals-in-one-window
While I personally prefer a tabbed style terminal emulator, I can see the appeal of this setup, especially if you live in the CLI.
NOTE to OpenSUSE users
If you are using Leap 42.1 or higher, ignore the instructions at the link and just type "zypper in terminator" from a root shell, or find the terminator package in YaST2's software manager.
#Linux #CommandLine
http://www.linuxandubuntu.com/home/terminator-a-linux-terminal-emulator-with-multiple-terminals-in-one-window
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