Archive for the ‘*nix’ Category
Posted by jpluimers on 2026/02/06
Historically I have been using Uptime Robot a lot, but in practice they are only good for HTTP/HTTPS uptime checking and TCP connection checking. SMTP checking requires more than just a valid TCP check which they can’t, so I took a look at hetrixtools.com.
They advertise being forever free when using a limit number of Uptime/Blacklist endpoints as per
[Wayback/Archive] Free Uptime Monitor & Blacklist Monitor- HetrixTools
- 15 Uptime Monitors • 1 Minute Interval
- 32 Blacklist Monitors • Checked Everyday
FREE Forever!
Unlike many other free uptime checking tools, their interval is better.
A thing to consider is that, like many online-first companies, they do not provide company details on either of these pages which you have to agree with when signing on for their service:
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Posted in *nix, hetrixtools, Monitoring, PagerDuty, Power User, Uptimerobot | Leave a Comment »
Posted by jpluimers on 2026/01/29
I totally agree with the first comment of [Wayback/Archive] Naming Files and Directories the Right Way – YouTube as it holds not just for file management, but for naming anything including software development:
I’ve watched many videos on file management, but this one explains naming very clearly.
- 0:31 Rule 1: No Spaces
- 2:40 Rule 2: Avoid Special Characters
- 3:43 Rule 3: Be Descriptively Concise
- 4:24 Rule 4: Case Sensitivity
- 5:00 Rule 5: Dates and Sorting
- 6:40 Rule 6: Be Consistent!
--jeroen
Posted in *nix, Apple, BSD, Development, Linux, Mac OS X / OS X / MacOS, Power User, Software Development, Windows | Leave a Comment »
Posted by jpluimers on 2026/01/28
Posted in *nix, *nix-tools, bash, bash, Development, DNS, Hardware Development, Internet, Power User, Raspberry Pi, Scripting, Software Development | Leave a Comment »
Posted by jpluimers on 2026/01/15
On OpenWRT GL.iNET based devices, the WireGuard client does not restart upon reboot, even if it was started before rebooting.
Hopefully the /usr/bin/wireguard_watchdog script will help with this as others indicates it should.
My first try was no succes, but since it is supposed to run from cron it does no output. The script on GL-SFT1200 firmware version 3.215, script /usr/bin/wireguard_watchdog is different from the one in the OpenWRT repository, so it needs some investigation.
Some links for checking this out:
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Posted in *nix, *nix-tools, ash/dash, ash/dash development, Development, GL-AR300M, GL.iNet, GL.iNET GL-SFT1200, OpenWRT, Power User, Scripting, Software Development | Leave a Comment »
Posted by jpluimers on 2026/01/07
Often connections are TCP based, but sometimes UDP is all you have to test with, so I was quite surprised that testing that was quite forward. The solutions by [Wayback/Archive] How to Do a UDP Ping in Linux works on any platform where you can have nmap or netcat on installed (which by now is almost all platforms including Windows):
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Posted in *nix, *nix-tools, Apple, BSD, Mac OS X / OS X / MacOS, netcat, nmap, Power User, Windows | Leave a Comment »
Posted by jpluimers on 2025/12/24
[Wayback/Archive] See a List of All Wi-Fi Networks a Mac Has Previously Connected To
n modern versions of Mac OS, like macOS Mojave, Catalina, Sierra, OS X El Capitan, and Yosemite, you can shorten the syntax considerably as so:
defaults read /Library/Preferences/SystemConfiguration/com.apple.airport.preferences |grep SSIDString
In prior versions of Mac OS X, you can opt for the same as the above command, or use the lengthier string below with heavy regex:
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Posted in *nix, *nix-tools, Apple, bash, bash, Development, Mac, Mac OS X / OS X / MacOS, MacBook, Power User, Scripting, Software Development | Leave a Comment »
Posted by jpluimers on 2025/12/10
A while ago I got an error 103 using both Beyond Compare. That did not whos the connection log or error reason, but WinSCP did: it mentioned unexpected output during the logon.
I got reminded that I had already solved this error before via [Wayback/Archive] SSH login works but SFTP login doesn’t – Server Fault (thanks [Wayback/Archive] qreon and [Wayback/Archive] Paulus):
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Posted in *nix, *nix-tools, bash, bash, Beyond Compare, Communications Development, Development, Internet protocol suite, Power User, Scripting, SFTP, Software Development, SSH, TCP, Windows, WinSCP | Leave a Comment »
Posted by jpluimers on 2025/11/29
Besides the August 2025 XKCD infrastructure dependency inspired cartoon on the right, the more recent and great [Wayback/Archive] XCKD: Dependency derivative below is a monumental piece as it combines the recent:
- fiber outage of the Internet Archive
- DoS of Cloudflare by itself
- AWS us-east-1 dependencies outage
- Crowdstrike DoS of Windows machines
- framework-du-jour mentality in the JavaScript world
- many more¹
Image [Wayback/Archive] 36247840bf294a9d.png (1080×1389) from [Wayback/Archive] xyla 🐀🪇: “someone pls alt text this shit…” – buy shitpost cheap:
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Posted in *nix, Amazon.com/.de/.fr/.uk/..., AWS Amazon Web Services, C, CDN (Content Delivery Network), Cloud, Cloudflare, cURL, Development, Fun, Hardware, Infrastructure, ISP, JavaScript/ECMAScript, Network-and-equipment, Node.js, npm, Power User, Rust, Scripting, Software Development, Web Development | Tagged: Meme, ProgrammerHumor | Leave a Comment »
Posted by jpluimers on 2025/11/14
The plan was to run a Postfix secondary MX inside a docker container.
Below are many links that might help me to get that going.
For now, I think this is the shortlist of solutions to try:
- Docker Mailserver
- Mailcow
- Mailu
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Posted in *nix, *nix-tools, Cloud, Communications Development, Containers, Development, Docker, Infrastructure, Internet protocol suite, Kubernetes (k8n), postfix, Power User, SMTP | Tagged: 254, 29, 52, 787, DMARC, domains, set | Leave a Comment »
Posted by jpluimers on 2025/11/12
This finally made me perform the (long overdue) migration from Sendmail to Postfix:
The Sender Rewriting Scheme (SRS) is a technique to forward mails from domains which deploy the Sender Policy Framework (SPF) to prohibit other Mail Transfer Agents (MTAs) from sending mails on their behalf. With SRS, an MTA can circumvent SPF restrictions by replacing the envelope sender with a temporary email address from one of their own domains. This temporary address is bound to the original sender and only valid for a certain amount of time, which prevents abuse by spammers.
[Wayback/Archive] roehling/postsrsd: Postfix Sender Rewriting Scheme daemon
Via a long queste to figure out why Gmail every now and then bounces forwarded messages because of Sender Policy Framework (SPF). Below are a few of the links that brought me here in mostly reverse order, but first some links that should help me further on the topic of Postfix virtual aliases.
The sendmail setup had some features not covered below (like a catch-all forward for email to addresses virtual domains not covered by a virtual alias) which I hopefully can cover later.
One thing learned both over the past decades and related postfix material: use separate servers or containers for each of your functions. So do not mix web-hosting, outgoing mail, incoming mail, fail2ban and others on the same server.
Links:
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Posted in *nix, *nix-tools, Communications Development, Development, Internet protocol suite, postfix, Power User, sendmail, SMTP | Tagged: Reload | Leave a Comment »
The Wiert Corner - irregular stream of stuff 