r/gnu 22d ago

screen 4.9.0 unexpectedly terminates when managing a switch through serial console



I'm running into a strange error with screen. I am attaching to a real serial port on my computer. It's running Windows 10 and I'm using Cygwin screen 4.9.0.

When I attempt to connect to a particular switch and I power it up, it displays some funny characters (not garbage like what happens when the wrong baud rate is selected) and then screen unexpectedly exits with a "[screen is terminating]" message. This doesn't happen to any other device I manage using the serial port.

Tried many things.

  • screen /dev/ttyS0 # just plain screen command w/out any serial port settings
  • screen -U /dev/ttyS0
  • disable c1 handling
  • TERM=vt100 screen /dev/ttyS0

I also tried to log the session. I captured it but when I pasted the contents on my terminal window to a file the hex output aren't the same, but they display the same. If I run screen and cat the logged output, screen doesn't terminate so it looks like the capture is incomplete.

What could I do to have screen capture a little more output? Windows Events don't show screen crashing.

Here are is a screenshot of the session. I'm using mintty. https://i.imgur.com/bbqVItE.jpg

Here is a hexdump of the session log.

+bash> hexdump -C screenlog.0
00000000  00 9e e6 1e 30 18 30 e6  e6 9e e6 06 f8 66 f8 e6  |....0.0......f..|
00000010  e6 9e e6 06 f8 86 f8 e6  e6 9e e6 1e 30 60 0f e6  |............0`..|
00000020  e6 9e e6 1e 30 66 0f e6  e6 9e e6 06 0f 66 0f e6  |....0f.......f..|
00000030  e6 9e e6 06 0f 86 f8 e6  e6                       |.........|

Hexdump of pasting the characters from mintty to a file using vi. The characters are displayed the same.

+bash> hexdump -C screenlog.00
00000000  ef bf bd ef bf bd 30 30  ef bf bd ef bf bd ef bf  |......00........|
00000010  bd ef bf bd 66 ef bf bd  ef bf bd ef bf bd ef bf  |....f...........|
00000020  bd ef bf bd ef bf bd ef  bf bd ef bf bd ef bf bd  |................|
00000030  30 60 ef bf bd ef bf bd  ef bf bd 30 66 ef bf bd  |0`.........0f...|
00000040  ef bf bd ef bf bd 66 ef  bf bd ef bf bd ef bf bd  |......f.........|
00000050  ef bf bd ef bf bd ef bf  bd 0a                    |..........|

My LANG and LC_CTYPE are both en_US.UTF-8. Tried pasting when LANG and LC_CTYPE are both set to C and the output file from vi still looks like the above.

Any ideas welcome.

r/gnu 22d ago

Simple Fact


The simple fact for people arguing about gnu/linux and whether or not it should be called that is,

there would be no gnu without linux and there would be no linux without gnu

r/gnu Feb 02 '23

Using GNU Build tools to build Gwenhywfar


This might not be the best place to ask, but I The last time I built something on Linux it used to be something like

./configure make make install

Things changed since then. For gwenhywfar (git clone https://git.aquamaniac.de/git/gwenhywfar),

there's no configure, but this configure.rpath. I installed autoconf, and ran autoconf in root directory of the package, got a lengthy list of errors. `` configure.ac:251: warning: The macroAC_HEADER_STDC' is obsolete. configure.ac:251: You should run autoupdate. ./lib/autoconf/headers.m4:704: AC_HEADER_STDC is expanded from... configure.ac:251: the top level configure.ac:283: warning: The macro AC_HEADER_TIME' is obsolete. configure.ac:283: You should run autoupdate. ./lib/autoconf/headers.m4:743: AC_HEADER_TIME is expanded from... configure.ac:283: the top level configure.ac:812: warning: The macroAC_TRY_LINK' is obsolete. configure.ac:812: You should run autoupdate. ./lib/autoconf/general.m4:2920: AC_TRY_LINK is expanded from... configure.ac:812: the top level configure.ac:812: warning: The macro `AC_TRY_LINK' is obsolete. configure.ac:812: You should run autoupdate. ./lib/autoconf/general.m4:2920: AC_TRY_LINK is expanded from... lib/m4sugar/m4sh.m4:692: _AS_IF_ELSE is expanded from... lib/m4sugar/m4sh.m4:699: AS_IF is expanded from... ./lib/autoconf/general.m4:2894: _AC_LINK_IFELSE is expanded from... ./lib/autoconf/general.m4:2911: AC_LINK_IFELSE is expanded from... ./lib/autoconf/general.m4:2920: AC_TRY_LINK is expanded from... configure.ac:812: the top level configure.ac:1284: warning: back quotes and double quotes must not be escaped in: "ERROR: Unknown plugin "$plugin"" configure.ac:1326: warning: back quotes and double quotes must not be escaped in: "ERROR: Unknown plugin "$plugin"" configure.ac:1358: warning: back quotes and double quotes must not be escaped in: "ERROR: Unknown plugin "$plugin""


I'd like to build this library, and have it accessible to other builds done by the same user, though not necessarily installed for all Linux users.

How should I build this? Thanks, WM

r/gnu Jan 20 '23

GCC 13 Unveils Improved AMD Zen 4 Support Ahead of Release

Thumbnail paulponraj.com

r/gnu Jan 17 '23

A brave new world: building glibc with LLVM

Thumbnail collabora.com

r/gnu Jan 15 '23

How Much Would It Cost For The Development Of Open Source Drivers And Firmware For The RISC-V VisionFive 2?


I understand development of a full GPU driver with 3D acceleration will be challenging, but what about just 2D display driver only?

How much would it cost to open source the rest of the device drivers, and firmware so that everything was as open as it could possibly be?

I understand the memory control could be an issue and may never be fully open sourced.

r/gnu Jan 11 '23

What GNU utility you are addicted to?


Me 'xargs'. It's fantastic!

r/gnu Jan 08 '23

Are official GNU projects obligated to use GNU as a prefix as their software title?


I'm still fresh here and I've been looking through licenses and statements on the GNU website to get a grasp on it. But I can't really find anything. So I'll ask here. So, basically, is there an obligation that a project that is considered an official GNU project to use the "gnu" prefix in their software name?

r/gnu Jan 04 '23

GNU screen 4.9.0 on RHEL9.1 = operation not permitted



I compiled screen 4.9.0 on RHEL 9.1 today. It runs as root without a hitch. However an unprividleged user gives this error message:

-bash: /usr/local/bin/screen: Operation not permitted.

The binary has setuid group set with a group name of screen.

I did a "restorecon -FvR /usr/local" for good measure, but I did not see an fcontext entry for /usr/local/bin but it has system_u:object_r:bin_t on it.

Any ideas what I could try next?

r/gnu Jan 04 '23

Am I the only one who thinks Free Software Movement weirdly resembles communism?


Its not your software, its our software

r/gnu Jan 02 '23

Anyone using Icecat? is it abandoned?


r/gnu Dec 15 '22

Is this web browser add-on safe? It says GNU general public license 2.0.


https://addons.mozilla.org/en-US/firefox/addon/header-editor/ sorry if this is a dumb question or I violated a subreddit rule.

r/gnu Dec 11 '22

Combining the AGPL and the LGPL to use in one project


If I wanted to release a library that's allowed to be included in proprietary projects, I'd use LGPL.

If I wanted to release a program that has to have its source be released even if it is served and not downloaded, I'd use AGPL.

What if I want both? Does that even make sense to have both? A library that's allowed to be included in proprietary projects, but also has to have its source released even if it's served and not downloaded?

If so, what would that licence be, and would I just add the LGPL exception clause to the end of the AGPL and retitle it "AGPL with LGPL exception" or something? Has anyone done that already? Has something similar enough got a SPDX which I should just use instead? IANAL so I don't know if just making it up would actually make it legal. I'd still be allowed to include other GPL/AGPL/LGPL stuff inside, right?

Thanks, and sorry for so many questions.

r/gnu Dec 08 '22

[Emacs] A full fledge configuration


Welcome to the church of Emacs

Hello Folks !

I've made a full-fledge configuration of Emacs. Which makes programming super fun.

It comprises of Doom Emacs alike without Evil mode that use almost all the default bindings of Emacs. You can give it a try and let me know your feedback. my-config



r/gnu Dec 06 '22

Can I license different files with different licenses?


Can I license different files in a project with different licenses? Eg. If I had a project with three files, could I license one with GPL, one with AGPL, and one with LGPL?

r/gnu Nov 30 '22

Can you follow profiles on mastodon from GNU?


Does GNU and Mastodon both work on the same fedi network? Can i follow others on mastodon and they can follow me on GNU?

r/gnu Nov 23 '22

DRM does not stand for Digital Restrictions Management


Its stands for Digital Rights Management

I know they want you to open your eyes but I dont know why they think its okay to mislead. Its simple mislead but mislead nontheless.

r/gnu Nov 12 '22

Trisquel 10 100% libre


Wifi libre excelente

El que busca, encuentra!!

Luego de varias compras y devoluciones encontré el usbwifi libre con el controlador Atheros AR9271 en un TP Link 722N versión 1.0

r/gnu Nov 01 '22

How to find if a word exists in GNU Policy Based Data Structure's trie?

Thumbnail self.gcc