The Wiert Corner – irregular stream of stuff

Jeroen W. Pluimers on .NET, C#, Delphi, databases, and personal interests

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Archive for the ‘Power User’ Category

If you are a KDE neon user, reinstall your distro now! | CIO

Posted by jpluimers on 2016/11/18

Security always has the human factor involved which means that we screw up like here:

Source: [WayBack] If you are a KDE neon user, reinstall your distro now! | CIO

A little blunder was committed by the core developers that made the entire archive insecure:

“Best practice when setting that up is to use the trusted SSH protocol to open a tunnel and upload through that,” said Riddell, “Unfortunately in setting up that new archive I had it listening for uploads on the whole network not just the local SSH tunnel.”

–jeroen

via: [WayBack] hmmm – looks legithttp://www.cio.com/article/3142789/linux/if-you-are-a-kde-neon-user-reinstall-your-distro-now.html – Joe C. Hecht – Google+

Posted in Power User, Security | Leave a Comment »

Getting the vendor from an ethernet network MAC address on-line through the Wireshark OUI Lookup Tool.

Posted by jpluimers on 2016/11/18

In networks, often you want to know which manufacturer or vendor is behind a MAC address.

An easy way to look this up on-line is by using the
Wireshark · OUI Lookup Tool which should have had MAC or MAC address in the title.

It uses both the extensive /etc/manuf Wireshark Ethernet vendor codes and well-known MAC address prefixes (which is a long text file generated from several sources). Some of the prefixes are just the 24-bit (6-hex digit) OUIs, but others are much more fine grained.

What’s really cool is that the tool accepts a very lenient formatting of inputs: full, partial, various hex separators (including none), case insensitive, and vendor names/abbreviations. So entries like these magically work.

0000.0c
08:00:20
01-00-0C-CC-CC-CC
missouri

–jeroen

Posted in Ethernet, Network-and-equipment, Power User | Leave a Comment »

tmux attach to named session or create when it doesn’t exist yet – via: How to start tmux with attach if a session exists – Unix & Linux Stack Exchange

Posted by jpluimers on 2016/11/16

In my alias list:

alias "tmux-attach-or-create-main-session=tmux new-session -A -s main"

Via User Wesley Baugh – Unix & Linux Stack Exchange who answered:

If naming your session is okay, then it’s easy to do with the new-session command:

tmux new-session -A -s main

where main is the session name that will be attached to or created if needed.

From man tmux

 The -A flag makes new-session behave like attach-session if session-name already exists; in this case, -D behaves like -d to attach-session.

–jeroen

Source: How to start tmux with attach if a session exists – Unix & Linux Stack Exchange

Posted in *nix, *nix-tools, Linux, openSuSE, Power User, SuSE Linux, tmux | Leave a Comment »

`xcode-select –install` required for OS X 10.9 Xcode command-line tools (like `zlib-devel`)

Posted by jpluimers on 2016/11/16

Hopefully this was a one time oversight from Apple, but on OS X 10.9 (Mavericks) the Xcode command-line tools cannot be installed from the Xcode Preferences pane.

You have to install them from the command-line:

xcode-select --install

There is one catch though: it might fail as you first have to start Xcode once and accept the license agreement.

You need them for instance when playing with zlib-devel (for instance when creating your own openssl builds).

–jeroen

Posted in Apple, Development, Mac OS X / OS X / MacOS, OS X 10.9 Mavericks, Power User, Software Development, xCode/Mac/iPad/iPhone/iOS/cocoa | Leave a Comment »

OpenSuSE and logging: no more syslogd; journald is default, you can use rsyslog or syslog-NG as syslogd replacements

Posted by jpluimers on 2016/11/15

In the 1990s and early 2000s I did a lot of Unix-Like (Minix, SunOS, HP-UX, Xenox) and later Linux (mostly RedHat and SuSE) work. The internet and Linux weren’t as big as they are now and old stuff was still in use including syslogd.

So recently wanting to do more on the Linux side of things using OpenSuSE (as 15+ years ago, I spent most of my time with SuSE Linux) and assumed logging was still done using syslogd like Mac OS X does.

Boy, I was wrong. Like the internet and lots of other things, logging on OpenSuSE has fragmented in at least these three categories of which two syslog implementations (but syslogd is deprecated and – according to the URC #SUSE Channel – unmaintained):

  • journald (installed by default on my Tumbleweed text-only systems)
  • rsyslog (which is supposed to be default on modern OpenSuSE installs but somehow isn’t on my Tumbleweed but is on 13.1 and 13.2)
  • syslog-ng
  • proprietary logging (of many applications in /var/log like named, apache, etc)

There seems to be heated debates on what to use when, so I’ll try to stick with the defaults as much as possible.

A few things I need to sort out:

  1. where is journald persisted?
  2. how can journald being rotated?
  3. what to do with packages that require one form of syslog or the other?
    • not sure yet
  4. can I direct journald to a syslog implementation?
  5. how does this apply to other distros?
    • not sure yet

Tonu Su (TSu2) posted an elaborate answer on the above questions on the OpenSuSE forums.

–jeroen

via:

Posted in *nix, *nix-tools, About, Linux, openSuSE, Power User, RedHat, SuSE Linux, Tumbleweed | 2 Comments »

Audio Tape Recovery – recording old audio cassettes on modern hardware

Posted by jpluimers on 2016/11/14

I need this one day: Audio Tape Recovery – Saving the Tapes

Recording done on an IBM ThinkPad X30 using Gnome Sound Recorder, post processing on an IBM ThinkPad X200 using Audacity.

–jeroen

via Will Hill commenting on  Watch how old technology can make a comeback with trends, product quality and nostalgia. This is the last cassette factory in the world and the machines… – Jan Wildeboer – Google+

Posted in Audacity, Audio, History, LifeHacker, Media, Power User | Leave a Comment »

Can I connect to or view abandoned ssh sessions?

Posted by jpluimers on 2016/11/14

Boy  I wish I had known about screen and tmux years ago. Screen is such a generic term that I never bumped into it, but tmux is easier to find and I like it more. When on the road, I regularly loose SSH sessions, so I’ve been starting tmux ever since I discovered it and reattach to it whenever needed thereby getting the same exact she’ll I was connected to.
http://unix.stackexchange.com/q/598/69111

–jeroen

Posted in *nix, *nix-tools, Communications Development, Development, Linux, openSuSE, Power User, SSH, SuSE Linux, TCP | Leave a Comment »

how to resize (grow) device partition of a multi-device BTRFS filesystem?

Posted by jpluimers on 2016/11/11

To grow you must first change the size of the container: the partition, the LV, or arraydevice. Then you can resize the file system. It’s the same with XFS, and NTFS. I’m only aware of Apple’sdiskutil resizevolume command that resizes the flavors of HFS+ and at the same time sets the new end valuefor the partition entry.

Source: Development of the BTRFS linux file system (not yet archived at the WayBack machine)

I will need the above for a single disk device having a BTRFS partition sandwiched between a swap and xfs partition:

# parted -l
Model: VMware Virtual disk (scsi)
Disk /dev/sda: 21.5GB
Sector size (logical/physical): 512B/512B
Partition Table: msdos
Disk Flags: 

Number  Start   End     Size    Type     File system     Flags
 1      1049kB  1562MB  1561MB  primary  linux-swap(v1)  type=82
 2      1562MB  17.7GB  16.1GB  primary  btrfs           boot, type=83
 3      17.7GB  21.5GB  3799MB  primary  xfs             type=83

I’ll likekly be:

  1. extend the disk inin ESXi
  2. use gparted to move the xfs partition to the end of the disk
  3. use gparted to extend the btrfs partition
  4. use btrfs to extend the volume inside the btrfs partition

I might be able to do all this from the gparted live CD as moving xfs and growing btrfs is on the GParted — Features list.

Fingers crossed. Luckily I’ve backups (:

–jeroen

Posted in *nix, ESXi4, ESXi5, ESXi5.1, ESXi5.5, ESXi6, Linux, openSuSE, Power User, SuSE Linux, Tumbleweed, VMware, VMware ESXi | Leave a Comment »

openSuSE Tumbleweed: solution for `ImportError: No module named pkg_resources`

Posted by jpluimers on 2016/11/11

If ever on openSuSE Tumbleweed you get an error ImportError: No module named pkg_resources then check you have the installed the python-setuptools package it is different from python3-setuptools which was installed by default but is not the default python used.

This is how to install it:

zypper install python-setuptools

Tools like speedtest-cli require it.

The odd thing: on a Mac, the homebrew speedtest-cli installed and ran with no additional packages needed:

retinambpro1tb:tmp jeroenp$ brew install speedtest-cli
==> Downloading https://github.com/sivel/speedtest-cli/archive/v0.3.2.tar.gz
==> Downloading from https://codeload.github.com/sivel/speedtest-cli/tar.gz/v0.3.2
######################################################################## 100.0%
🍺 /usr/local/Cellar/speedtest_cli/0.3.2: 5 files, 52K, built in 2 seconds
retinambpro1tb:tmp jeroenp$ speedtest-cli
Retrieving speedtest.net configuration...
Retrieving speedtest.net server list...
Testing from Routit BV (37.153.243.246)...
Selecting best server based on latency...
Hosted by ExtraIP (Amersfoort) [3.99 km]: 6.488 ms
Testing download speed........................................
Download: 49.89 Mbit/s
Testing upload speed..................................................
Upload: 47.81 Mbit/s

(this is on one of my fiber connections back when it was 50/50 megabit).

Note that for both the web interface of speedtest.net and command-line versions (like Python based speedtest-cli) sometimes needs some fiddling with chosen servers and repeated measurements to get a consistent average as quite some factors can influence the measurements.

For my home location, this one gives me the most consistent results for my fiber connections (they’re so good and reliable that I don’t have ADSL or cable any more):

speedtest-cli --server 3629

You can get the list of servers ordered by increasing distance using this command:

speedtest-cli --list | head -n 20

–jeroen

Posted in *nix, *nix-tools, Internet, Linux, openSuSE, Power User, SpeedTest, SuSE Linux | 2 Comments »

Old Google Charting API: tools for still using them

Posted by jpluimers on 2016/11/10

While mocking the ScaleMM documentation, I bumped into a chart that I thought was an image, but is in fact generated by the (now deprecated) Image Charts API from Google.

In fact it is generated on the fly from a URL: http://chart.apis.google.com/chart?chxr=0,0,16|1,0,14682…&nonsense=something_that_ends_with.png

Compare the two below. They are identical (:

Static ScaleMM1 comparison chart

Static ScaleMM1 comparison chart

URL based ScaleMM1 comparison chart

URL based ScaleMM1 comparison chart

Even though the API is deprecated Google has no plans to turn it of, so it still works and is the easiest way to get charts into a Markdown or reStructuredText document.

In practice, it doesn’t matter if you use the chart.apis.google.com or chart.googleapis.com domain: they give the same results the same.

As I wanted to convert the results.txt to a chart, I dissected the above URL, looked up the definitions of the URL parameters (the trickiest: cds for lxy graphs and the combination of chds and chxr, easier: chls) and created a new URL for the chart below.

Read the rest of this entry »

Posted in Delphi, Development, Google, Power User, Software Development | Leave a Comment »