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

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Archive for the ‘*nix’ Category

pure-bash-bible/ – book for doing things in bash without external tools

Posted by jpluimers on 2018/09/21

[WayBack] pure-bash-bible/ at master · dylanaraps/pure-bash-bible · GitHub:

The goal of this book is to document known and unknown methods of doing various tasks using only built-in bash features. Using the snippets from this bible can help remove unneeded dependencies from scripts and in most cases make them faster. I came across these tips and discovered a few while developing neofetchpxltrm and other smaller projects.

The snippets below are linted using shellcheck and tests have been written where applicable. Want to contribute? Read the It outlines how the unit tests work and what is required when adding snippets to the bible.

See something incorrectly described, buggy or outright wrong? Open an issue or send a pull request. If the bible is missing something, open an issue and a solution will be found.



Posted in *nix, *nix-tools, bash, bash, Development, Power User, Scripting, Software Development | Leave a Comment »

Not cool: openSuse Tumbleweed switched DHCP clientID algorithm on Raspberry Pi 3, so now all devices get a non-static DHCP address

Posted by jpluimers on 2018/09/15

Not sure in which changeset this happened, but here is one example:

  1. old DHCP client ID 1:b8:27:eb:1a:b1:ec
  2. new DHCP client ID ff:eb:78:a9:4:0:1:0:1:22:6:67:49:b8:27:eb:78:a9:4

The first one was marked static in the DHCP server, which means the Raspberry Pi now did get a different IP address.

This messes up a few places that cannot do proper address resolution.

Anyone who knows where this has changed / is configured?

These did not help finding the cause:


Posted in *nix, Hardware Development, Linux, openSuSE, Power User, Raspberry Pi, SuSE Linux, Tumbleweed | 4 Comments » TLS certificate does not match domain name

Posted by jpluimers on 2018/09/07

One of the domains not yet monitored at, was the altd download server for ISOs and installers on http and https level. Ultimately you want https, as most of these are about installers, so you do not want any man-in-the-middle to fiddle with them.

TLS on altd fails

Upitmerobot is not yet smart enough to check validity of TLS certificates on https connections.

Chrome, Firefox, Safari, Internet Explorer, wget, curl and ssllabs however are.

altd hides as much from itself as possible

Uptimerobot did not like monitoring the plain and URLs, because the altd is not browsable, so it tries to hide most of its structure from access. This means they both return an odd response:

Those responses are actually 404 errors (note the - minus sign after curl --trace-ascii: it sends the trace to stdout):

$ wget
--2018-09-05 10:44:23--
Resolving (,
Connecting to (||:80... connected.
HTTP request sent, awaiting response... 404 Not Found
2018-09-05 10:44:23 ERROR 404: Not Found.

$ curl --verbose
*   Trying
* Connected to ( port 80 (#0)
> GET / HTTP/1.1
> Host:
> User-Agent: curl/7.54.0
> Accept: */*
< HTTP/1.1 404 Not Found
< Server: Apache
< Content-Type: text/html; charset=iso-8859-1
< Content-Length: 16
< Date: Wed, 05 Sep 2018 08:45:57 GMT
< Connection: keep-alive
* Connection #0 to host left intact
File not found."

$ curl --trace-ascii -
== Info:   Trying
== Info: TCP_NODELAY set
== Info: Connected to ( port 80 (#0)
=> Send header, 84 bytes (0x54)
0000: GET / HTTP/1.1
0010: Host:
002c: User-Agent: curl/7.54.0
0045: Accept: */*
<= Recv header, 24 bytes (0x18)
0000: HTTP/1.1 404 Not Found
<= Recv header, 16 bytes (0x10)
0000: Server: Apache
<= Recv header, 45 bytes (0x2d)
0000: Content-Type: text/html; charset=iso-8859-1
<= Recv header, 20 bytes (0x14)
0000: Content-Length: 16
<= Recv header, 37 bytes (0x25)
0000: Date: Wed, 05 Sep 2018 08:47:19 GMT
<= Recv header, 24 bytes (0x18)
0000: Connection: keep-alive
<= Recv header, 2 bytes (0x2)
<= Recv data, 16 bytes (0x10)
0000: File not found."
File not found."== Info: Connection #0 to host left intact

This is also the reason that WayBack does not want to archive that link, but it can be archived at [Archive.is

Luckily, a Google search for revealed there is a non-installer file short enough (~72 kibibytes) for Uptime robot to check, so it now verifies it can access these:


Read the rest of this entry »

Posted in *nix-tools, cURL, Encryption, HTTPS/TLS security, Power User, Security, wget | Leave a Comment »

Some Linux mail solutions

Posted by jpluimers on 2018/09/07

Too bad most of them are very picky to the Linux distributions they run on.


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

I am on a Mac that is bound to an AD Domain. The AD Domain has a 90 days pass…

Posted by jpluimers on 2018/08/27

[WayBack] I am on a Mac that is bound to an AD Domain. The AD Domain has a 90 days password expiration policy. When will my password expire? $ cat bin/is-passwor… – Kristian Köhntopp – Google+

For my link archive:

Script copied to [WayBack] Kristian Köhntopp: I am on a Mac that is bound to an AD Domain. The AD Domain has a 90 days password expiration policy. When will my password expire?  · GitHub


Posted in *nix, Apple, bash, Development, Mac, MacBook, MacBook Retina, MacBook-Air, MacBook-Pro, MacMini, Power User, Scripting, Software Development | Leave a Comment »

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