Category Archives: CLI

LS Style After Devuan 3 or Debian 10 Update

After Devuan 3 update ls output showed characters, that are not really in the directory listing. The reason is that “ls” draws quotes around filenames with spaces. This is a bug from my point of view, ls should never change … Continue reading

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Time Format after Devuan 3 and Debian 10 Update

After updating to Devuan 3 the date command shows 12hours am/pm but my days have 24 hours. The locale was always en_US.UTF8 to keep sane command and error output. Debian 10 thinks they had to fix the correct hour display … Continue reading

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MITMProxy and IOS 13

Problem: if you want to debug a IOS app with MITMProxy, the iPhone needs to trust the MITMProxy CA. This is done by going to http://mitm.it/ and clicking on the apple symbol. Then you have to accept the “profile” in … Continue reading

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Linux Live-boot Fails after Debian/Devuan Update

Problem: after updating from Debian 8 to Devuan 2 the overlay live-boot failes with “no such device” Discussion: I use a bootable USB stick combined with live-boot. In this case the USB stick partition 3 is a normal ext4 file … Continue reading

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Greenlock(-express) Letsencrypt Fails with ECONNRESET

Problem: after upgrading vom greenlock-express v2.0 to v2.5 and switching from acme-v1 to acme-v2 every attempt to register a new TLS cert with Letsencrypt fails with “ECONNRESET” Discussion: the new version of greenlock tries to validate the .well-known/acme-challenge file before … Continue reading

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Apache Start Hangs during Reboot of a KVM Virtual Server

Problem: Apache needs very long to start on a virtual server running on a KVM/QEMU virtual maschine. Solution: Apache needs a RNG (random number generator) for startup, probably because of TLS. A pure virtual maschine has no RNG device per … Continue reading

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Sparse Files Howto

Unix file systems like ext3/4 can store files which are partly empty more efficiently by not storing blocks with all zeros. These files are called sparse files. When reading these files every things works as normal but “all zero” blocks … Continue reading

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Remove ID3 Tags from Flac Files

Problem: Some flac players refuse to play some flac files, and even tools like an old ffmpeg can’t handle some flac files Solution: These flac files might have id3v2 tags which they realy should not, because flac uses vorbis style … Continue reading

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Block Internet per User/Service

If you like to block network access for certain users on a linux box it’s as simple as that: /sbin/iptables -I OUTPUT -m owner –uid-ower <USERNAME> -j DROP Username might also be the username of a running service.

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APT sources list

Problem: when debian goes from “testing” to “stable” to “oldstable” the package sources change. eg. jessie-updates are remove, same happened to jessie-backports The current file /etc/apt/sources.list for jessie (currently oldstable) could look like this deb http://ftp.debian.org/debian/ jessie main contrib non-freedeb … Continue reading

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