Blog

in the middle of upgrading my WordPress installation I exceeded my disk quota and I only saw “HTTP ERROR 500” from then on
- I got my friendly provider to increase my disk quota by “a little” for a couple of days – actually I was granted 300M for like 3 days
- https://www.elegantthemes.com/blog/tips-tricks/how-to-fix-the-500-internal-server-error-on-your-wordpress-website – following this web page I moved the wp-admin and wp-includes from a fresh version of WordPress to my installation directory (actually after moving my old ones aside, keeping in mind I would have to remove them in the near future)
- problem fixed
2017-11-20
extract timestamp from a gzip file
- https://unix.stackexchange.com/questions/79543/extract-timestamp-from-a-gzip-file/79546
- http://www.forensicswiki.org/wiki/Gzip
Try this:
```
$ <foo.gz dd bs=4 skip=1 count=1 | od -t d4
0000000 1036139973
0000004

# with extended versions of dd resp. od:

$ <foo.gz dd bs=4 skip=1 count=1 status=none | od ---format=d4 --address-radix=n
1036139973
```
- https://en.wikipedia.org/wiki/Unix_epoch – this is what the given command line shows you (actually with offsets around)
How to display a human readable time stamp from the one extracted?
- http://Jochen.Hayek.name/wp/blog-en/2017/10/26/how-to-translate-human-readable-time-to-epoch/ – … and esp. the other way round
2017-11-15
plan9port AKA “Plan 9 from User Space”
do not put the Plan 9 utilities’ directory a the beginning of your PATH!

“9base is a port of various original Plan 9 tools for Unix, based on plan9port“:
Optware-ng one my Synology NAS has a 9base package:
```
root@DiskStation $ ipkg files 9base
/opt/lib/9base/bin/...
/opt/lib/9base/lib/...
/opt/share/man/man1/...
```
2017-11-15

ipkg, opkg, Optware, Optware-ng, Entware, Entware-ng for my Synology NASes

Linux package management systems for embedded systems.

The utilities:

https://en.wikipedia.org/wiki/ipkg – the history
https://en.wikipedia.org/wiki/opkg – ipkg fork, the currently popular one

The repositories: Optware, Optware-ng, Entware, Entware-ng:

https://en.wikipedia.org/wiki/Optware – how it all started
https://github.com/Optware/Optware – outdated
https://github.com/Optware/Optware-ng – an Optware fork using opkg – supports PPC, i686, …; does not support x86-64 – this page has the installation instructions – they do use opkg, but they call it ipkg (that’s strange)
https://github.com/Optware/Optware-ng/wiki/IPKG-OPKG-Open-Package-Manager
https://github.com/Entware
https://github.com/Entware/Entware – the repository as of 2018-03-01 !!!!!!!!!!!!!!!!!!!!
https://github.com/Entware/Entware/wiki !!!!!!!!!!!!!!!!!!!!!!!!!!!!!
https://github.com/Entware/Entware/wiki/Install-on-Synology-NAS
!!!!!!!!!!!!!!!!!!!!!
https://github.com/Entware-ng/Entware-ng – yet another Optware fork – supports x86-64, armv5, armv7; does not support PPC – outdated as of 2018-03-01
https://entware.net/2018/03/01/Changelog.html – Entware-ng/Entware-ng is outdated as of now
https://github.com/Entware-ng/Entware-ng/wiki
https://github.com/Entware-ng/Entware-ng/wiki/Install-on-Synology-NAS – this page has the installation instructions

I am not following their advice regarding /opt/etc/init.d.

CAVEAT: (On the Synology NASes) the command line utilities outside /opt experience trouble getting loaded libraries from /opt/lib through LD_LIBRARY_PATH, so I remove /opt/lib from there in my startup script.

Synology model	CPU	/proc/cpuinfo	uname –machine	Entware	Entware-ng	Optware-ng
synology_apollolake_218+			x86_64	./.	x86-64
synology_cedarview_713+			x86_64	./.	x86-64
synology_armada370_ds115j			armv7l	./.	armv7
synology_88f6282_112+			armv5tel	–	armv5
synology_qoriq_213+	Freescale QorlQ P1022	e500v2	ppc		–	PowerPC e500v2

2017-11-15

WordPress: how do I remove “Uncategorized” from posts with more than 1 category?
- https://wordpress.stackexchange.com/questions/232436/how-do-i-remove-uncategorized-from-posts-with-more-than-1-category
A couple of months ago I had a bad plugin installed for a couple of days, and it deliberately removed categories from my posted articles. In the meantime I added proper categories again more or less systematically, but those articles where still tainted with the category “Uncategorized“. Now this is a way to clean them.
2017-11-11
how to move files from one git repo to another (not a clone), preserving history
- https://stackoverflow.com/questions/1365541/how-to-move-files-from-one-git-repo-to-another-not-a-clone-preserving-history
- http://gbayer.com/development/moving-files-from-one-git-repository-to-another-preserving-history/
2017-11-10
my ‘git log’ shows plain ESC sequences – how to get this right?
- http://git.661346.n2.nabble.com/git-log-escape-symbols-shown-as-ESC-33-and-ESC-m-td7602089.html
- https://stackoverflow.com/questions/25332598/how-to-suppress-display-of-escape-sequences-in-diff
Until right now my LESS environment variable did not include “R” for passing through ANSI codes.

Solutions:
- Either I add “R” explicitly,
- or I start git w/o LESS in its environment:
$ env LESS=-MMiR git log
$ env -u LESS git log
2017-11-08
rcs2git using Perl, Ruby, AWK
- https://github.com/knuta/rcs2git – using Perl
- https://github.com/JochenHayek/rcs2git – using Perl – I forked knuta’s version
- https://github.com/arnoldrobbins/simple-rcs2git – using AWK
- https://github.com/Oblomov/rcs-fast-export – using Ruby
- https://stackoverflow.com/questions/1619737/migrate-project-from-rcs-to-git
2017-11-07
how to translate human readable time to EPOCH (GNU coreutils (“date”), Perl, …) – resp. the other way round
- https://stackoverflow.com/questions/7357423/perl-human-readable-time-with-miliseconds-to-epoch
- https://www.gnu.org/software/coreutils/manual/html_node/Examples-of-date.html – making use of the ‘@’ feature of the date utility
```
$ date --date="2011/09/08 00:10:17.997" +%s # from human readable time to EPOCH
1315433417

$ date --utc --date="2011/09/08 00:10:17.997" +%s
1315440617

$ date -d @946684800 +"%F %T %z"
2000-01-01 01:00:00 +0100

$ date --utc --date='1970-01-01 946684800 seconds' +"%Y-%m-%d %T %z"
2000-01-01 00:00:00 +0000
```
2017-10-26
Key Reinstallation Attacks – breaking WPA2 by forcing nonce reuse
- https://www.krackattacks.com
2017-10-18