Archive for the ‘*nix-tools’ Category
Posted by jpluimers on 2026/02/25
Often I need to generate passwords or uuids (on some systems called guids). I usually try to do that in a relatively platform agnostic way as I use MacOS, Windows and Linux in various mixes for many reasons (for instance that I have had developed quite hefty RSI in the early 1990s of the and the best keyboard/pointing-device combination for is the MacBook built in keyboard/touchpad combination so basically MacBooks are my window to all other operating systems).
Generating randomly with a good random number generator them makes sense as for most usage, it is important that both passwords and uuids are hard to guess which means having an entropy that is as high as possible.
A cool thing about OpenSSL is that:
- most of not all systems have it installed (it was no coincidence I published Installing OpenSSL on Windows a few days ago)
- it has a very good pseudo-random number generator and as of [Wayback/Archive] OpenSSL version 1.1.1 first released in 2018 has solved the problem around [Wayback/Archive] Random fork-safety – OpenSSLWiki, see [Wayback/Archive] Our Review of the OpenSSL 1.1.1 Random Number Generation Update – OSTIF.org.
- it supports various useful output formats
hex (hexadecimal) and base64 (next to the default of octet – or by today’s naming convention byte – output)
The easiest to generate are passwords. Yes I know that password managers can do this too, but there are some systems I cannot use them on or sync between them (don’t you love the corporate world) so my aim is to use a random password generator in a platform agnostic way which usage is easy to remember. Read the rest of this entry »
Posted in *nix, *nix-tools, Apple, base64, bash, bash, Batch-Files, Conference Topics, Conferences, Development, Encoding, Event, HEX encoding, Mac, Mac OS X / OS X / MacOS, MacBook, OpenSSL, Power User, Python, Scripting, Software Development, Windows | Leave a Comment »
Posted by jpluimers on 2026/02/24
I needed to document how to install sed on Windows (which I did a long time ago after writing Plastic SCM: show the current changeset abstract (without files) on the commandline) and recently for some more scripting work(which I will blog on that later this week).
At the time of writing it was [Wayback/Archive] Chocolatey Software | GNU sed 4.8, but this Chocolatey command will install or upgrade to the most recent available version:
choco upgrade --yes sed
Of course, like yesterday’s post Installing OpenSSL on Windows, you could use winget or scoop for this as well. Finding out the commands is left as an exercise to the reader (;
Query: [Wayback/Archive] chocolatey sed – Google Search
–jeroen
Posted in *nix, *nix-tools, Chocolatey, Development, Power User, Scoop, Scripting, sed, Software Development, Windows, Windows Development, winget | 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:
Read the rest of this entry »
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):
Read the rest of this entry »
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:
Read the rest of this entry »
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):
Read the rest of this entry »
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 2025/11/14
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
Read the rest of this entry »
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 