sancho.s ReinstateMonicaCellio's questions

I mean to gzip all files *.vtu, at all depths below a given directory, in bash. I have such files at depths 1 and 2 below ./. I managed to do so with

$ gzip -v $(find . -name "*.vtu")

I could also use find ... -exec, and other combinations (see below).
Is there any way of doing it only with a capability of gzip (-r was my candidate)?

I expected

$ gzip -r -v "*.vtu"

where the pattern would not be expanded by the shell but expanded by gzip (and in a way to produce my intended result!), would work for this, but I get gzip: ...: No such file or directory with all combinations I tried. What I found is the following:

1. With shopt -s globstar (from here), the command gzip -v **/*.vtu seems to do exactly what I want.
2. If shopt | grep globstar gives globstar off, the command above does not work. In this case, I can use gzip -v */*.vtu, but it only works with files at depth=1. Likewise with gzip -v */*/*.vtu at depth=2.

In any case, I didn't find what is the effect/usefulness of flag -r.

Related:

1. gzip all files with specific extensions
2. https://stackoverflow.com/questions/10363921/how-to-gzip-all-files-in-all-sub-directories-in-bash

I mean to match (with ls, rm, etc.) files with names test10 to test18, test30 to test38, test22 to test23, with a single regex, in bash. I tried many variants around

$ ll "test([1,3][0-8]|22|23)" 

but I couldn't make it work. What is the correct way to do this?

I mean to connect from my Ubuntu 20.04.05LTS to a Windows machine with TeamViewer. I have just installed the .deb for TeamViewer. It only shows as TeamViewer Host, and when I launch it, it doesn't look like I was used to.

I don't see how to use it as a client, where I can simply enter the information for the server and connect to it.

Is that possible? How?

I mean to determine the clock speed. I am posting below the output of the various commands listed here.

For the max freq, I see 4 different sources, with 2 different values:

1. CPU max MHz: 3300,0000 from lscpu.
2. capacity: 3300MHz from lshw.
3. capacity: 3800MHz from sudo lshw.
4. Max Speed: 3800 MHz from dmidecode.

For the current freq, I see 4 different sources, with roughly 3 different values:

1. CPU MHz: 2100.000 from lscpu.
2. cpu MHz : 1691 (averaged by me) from cat /proc/cpuinfo.
3. Current Speed: 2600 MHz from dmidecode.
4. Detected 2594.332 MHz processor from cat /var/log/dmesg.

My observations:

1. There was a wide variation in the output obtained, for both the max freq and current freq. How to make sense of this? For instance, lshw gives different results with or without sudo. Is this expected? Which should be considered more reliable, and why?
2. The clock speed was even different among the 4 processors. Is such a wide variation expected?

Note: As appropriately asked by @hobbs, this OP was motivated by the need for understanding the relation between "Clock speed" (whichever variant corresponds), CPU freq spec, and memory speed spec (here there is also possibly more than one value, see e.g. dmidecode showing Memory Module Voltage: 3.3 V for DDR3 RAM).

Output:

$ lscpu | grep "MHz"
CPU MHz:                         2100.000
CPU max MHz:                     3300,0000
CPU min MHz:                     1200,0000

$ cat /proc/cpuinfo | grep "MHz"
cpu MHz         : 1753.417
cpu MHz         : 1200.000
cpu MHz         : 2212.235
cpu MHz         : 1600.000

$ lshw -c cpu | grep capacity
WARNING: you should run this program as super-user.
       capacity: 3300MHz
$ sudo lshw -c cpu | grep capacity
       capacity: 3800MHz

$ sudo dmidecode -t processor | grep "Speed"
        Max Speed: 3800 MHz
        Current Speed: 2600 MHz

$ cat /var/log/dmesg | grep "MHz processor"
[    0.000000] kernel: tsc: Detected 2594.332 MHz processor

$ cat /var/log/kern.log | grep "MHz processor"

I will update info as I find out

The problem

I am using a recently installed Lubuntu 20.04.3, in an old PC. I mean to connect via xRDP from both Ubuntu (remmina) and Windows 10 PCs, and so far I cannot from either.

What I see when connecting from Ubuntu 20.04.3, remmina:

1. Screen 1 with the message login failed for display 0.
   _{From logs below, I understand this is just a warning, but then an attempt to connect with display 10 (or display 11 if there is already an X connection using display 10) is successful.
   So I would only later bother about how to remove this initial attempt with display 0, or how to make it succeed.}
2. Screen 2 with the login prompt.
3. A brief black screen, and then the connection window closes.

How can I fix this?

Note: I don't think there is a problem with username/password. There are no special characters, nor capital letters in either. And I can ssh to that server with no problem from both Ubuntu and Win 10. Plus, logs below suggest this is ok.

What I tried so far

See below for specific info; none of this changed the outcome:

1. Installed required packages: xrdp xorgxrdp xserver-xorg-core xserver-xorg-input-all

2. Enabled the service.

3. Added two lines in /etc/xrdp/startwm.sh as shown under Fix Black Ubuntu Screen. Restaring the service.

4. Removed an issue with certifcates (Option 2 here), with sudo adduser xrdp ssl-cert Restaring the service. Upon connecting again, remmina asked me to accept certificates, which I did.

5. Edited /etc/X11/Xwrapper.config as shown here. Restaring the service.

6. Given the error message in ~/.xorgxrdp.11.log (failed to take device: Operation not permitted) and this solved similar problem (although not with xrdp), I tried enabling KMS (I learned radeon is the driver) with

   $ sudo nano /etc/initram-tools/modules
   (adding radeon at the end)
   $ sudo update-initramfs -u
   $ sudo shutdown -r
   

7. Logging out in the server and remote-connecting, as per this.

I am not sure about a few points:

1. Could the problem be related to the fact I am using Gnome in the client, and another WM in the server? If it could, how can I confirm or rule out this? How can I solve this? See below.
2. Could the problem be related to the first attempt at using display 0? If so, how could I remove that initial attempt, and use the available display (10, 11, etc.) in the first attempt?
3. Do I need any UFW rule, given I am at home, with all PCs connected to the same router? If so, which are the commands to set the rule/s?
4. Should I modify /etc/xrdp/xrdp.ini as shown here?
5. Is the excerpt from ~/.xsession-errors below indicative of what to try next? If so, what are the commands that should follow?
6. Is line [ERROR] g_tcp_bind(9, 6010) failed bind IPv6 (errno=98) and IPv4 (errno=22) the key for the solution? If so, what are the commands that should follow?
7. Can I do this without a VNC server? (I would keep the demand on my server as low as possible, it is an old PC). This and this mention the VNC server as a requirement.

Specific info

On firewall

$ sudo ufw status verbose
Status: inactive

On packages

$ dpkg -l | grep xrdp
ii  xorgxrdp                      1:0.2.12-1                    amd64   Remote Desktop Protocol (RDP) modules for X.org
ii  xrdp                          0.9.12-1                      amd64   Remote Desktop Protocol (RDP) server
$ dpkg -l | grep xserver
ii  x11-xserver-utils             7.7+8                         amd64   X server utilities
ii  xserver-common                2:1.20.11-1ubuntu1~20.04.2    all     common files used by various X servers
ii  xserver-xorg                  1:7.7+19ubuntu14              amd64   X.Org X server
ii  xserver-xorg-core             2:1.20.11-1ubuntu1~20.04.2    amd64   Xorg X server - core server
ii  xserver-xorg-input-all        1:7.7+19ubuntu14              amd64   X.Org X server -- input driver metapackage
ii  xserver-xorg-input-libinput   0.29.0-1                      amd64   X.Org X server -- libinput input driver
ii  xserver-xorg-input-wacom      1:0.39.0-0ubuntu1             amd64   X.Org X server -- Wacom input driver
ii  xserver-xorg-legacy           2:1.20.11-1ubuntu1~20.04.2    amd64   setuid root Xorg server wrapper
ii  xserver-xorg-video-all        1:7.7+19ubuntu14              amd64   X.Org X server -- output driver metapackage
ii  xserver-xorg-video-amdgpu     19.1.0-1                      amd64   X.Org X server -- AMDGPU display driver
ii  xserver-xorg-video-ati        1:19.1.0-1                    amd64   X.Org X server -- AMD/ATI display driver wrapper
ii  xserver-xorg-video-fbdev      1:0.5.0-1ubuntu1              amd64   X.Org X server -- fbdev display driver
ii  xserver-xorg-video-intel      2:2.99.917+git20200226-1      amd64   X.Org X server -- Intel i8xx, i9xx display driver
ii  xserver-xorg-video-nouveau    1:1.0.16-1                    amd64   X.Org X server -- Nouveau display driver
ii  xserver-xorg-video-qxl        0.1.5+git20200331-1           amd64   X.Org X server -- QXL display driver
ii  xserver-xorg-video-radeon     1:19.1.0-1                    amd64   X.Org X server -- AMD/ATI Radeon display driver
ii  xserver-xorg-video-vesa       1:2.4.0-2                     amd64   X.Org X server -- VESA display driver
ii  xserver-xorg-video-vmware     1:13.3.0-3                    amd64   X.Org X server -- VMware display driver

On the service (at the time of writing)

$ sudo systemctl status xrdp
[sudo] password for user1: 
● xrdp.service - xrdp daemon
     Loaded: loaded (/lib/systemd/system/xrdp.service; enabled; vendor preset: enabled)
     Active: active (running) since Wed 2021-11-03 07:17:27 -03; 46min ago
       Docs: man:xrdp(8)
             man:xrdp.ini(5)
    Process: 794 ExecStartPre=/bin/sh /usr/share/xrdp/socksetup (code=exited, status=0/SUCCESS)
    Process: 809 ExecStart=/usr/sbin/xrdp $XRDP_OPTIONS (code=exited, status=0/SUCCESS)
   Main PID: 821 (xrdp)
      Tasks: 2 (limit: 4114)
     Memory: 13.6M
     CGroup: /system.slice/xrdp.service
             ├─ 821 /usr/sbin/xrdp
             └─2270 /usr/sbin/xrdp

nov 03 07:51:49 server1 xrdp[2270]: (2270)(140250390095680)[DEBUG] xrdp_000008de_wm_login_mode_event_00000001
nov 03 07:51:49 server1 xrdp[2270]: (2270)(140250390095680)[INFO ] Loading keymap file /etc/xrdp/km-0000080a.ini
nov 03 07:51:49 server1 xrdp[2270]: (2270)(140250390095680)[WARN ] local keymap file for 0x0000080a found and doesn't match built in keym>
nov 03 07:51:50 server1 xrdp[2270]: (2270)(140250390095680)[DEBUG] xrdp_wm_log_msg: connecting to sesman ip 127.0.0.1 port 3350
nov 03 07:51:50 server1 xrdp[2270]: (2270)(140250390095680)[INFO ] xrdp_wm_log_msg: sesman connect ok
nov 03 07:51:50 server1 xrdp[2270]: (2270)(140250390095680)[DEBUG] xrdp_wm_log_msg: sending login info to session manager, please wait...
nov 03 07:51:50 server1 xrdp[2270]: (2270)(140250390095680)[DEBUG] return value from xrdp_mm_connect 0
nov 03 07:51:52 server1 xrdp[2270]: (2270)(140250390095680)[INFO ] xrdp_wm_log_msg: login failed for display 0
nov 03 07:51:52 server1 xrdp[2270]: (2270)(140250390095680)[DEBUG] xrdp_mm_module_cleanup
nov 03 07:51:52 server1 xrdp[2270]: (2270)(140250390095680)[DEBUG] Closed socket 16 (AF_INET6 ::1 port 33602)

On the last 2 connection attempts (at the time of writing), via tail -100 /var/log/xrdp.log. Note that the log for the second to last is much briefer (I wouldn't know why).

[20211103-08:12:23] [DEBUG] xrdp_wm_log_msg: connecting to sesman ip 127.0.0.1 port 3350
[20211103-08:12:23] [INFO ] xrdp_wm_log_msg: sesman connect ok
[20211103-08:12:23] [DEBUG] xrdp_wm_log_msg: sending login info to session manager, please wait...
[20211103-08:12:23] [DEBUG] return value from xrdp_mm_connect 0
[20211103-08:12:24] [INFO ] xrdp_wm_log_msg: login successful for display 11
[20211103-08:12:24] [DEBUG] xrdp_wm_log_msg: started connecting
[20211103-08:12:25] [INFO ] lib_mod_log_peer: xrdp_pid=2270 connected to X11rdp_pid=2309 X11rdp_uid=1000 X11rdp_gid=1001 client_ip=::ffff:192.168.0.139 client_port=42290
[20211103-08:12:25] [DEBUG] xrdp_wm_log_msg: connected ok
[20211103-08:12:25] [DEBUG] xrdp_mm_connect_chansrv: chansrv connect successful
[20211103-08:12:25] [DEBUG] Closed socket 16 (AF_INET6 ::1 port 33604)
[20211103-08:12:27] [DEBUG] Closed socket 12 (AF_INET6 ::ffff:192.168.0.176 port 3389)
[20211103-08:12:27] [DEBUG] xrdp_mm_module_cleanup
[20211103-08:12:27] [DEBUG] Closed socket 17 (AF_UNIX)
[20211103-08:12:27] [DEBUG] Closed socket 18 (AF_UNIX)
[20211103-08:20:06] [DEBUG] Closed socket 11 (AF_INET6 :: port 3389)
[20211103-08:20:06] [INFO ] address [0.0.0.0] port [3389] mode 1
[20211103-08:20:06] [INFO ] listening to port 3389 on 0.0.0.0
[20211103-08:20:06] [INFO ] xrdp_listen_pp done
[20211103-08:20:07] [DEBUG] Closed socket 7 (AF_INET6 :: port 3389)
[20211103-08:20:09] [INFO ] starting xrdp with pid 2430
[20211103-08:20:09] [INFO ] address [0.0.0.0] port [3389] mode 1
[20211103-08:20:09] [INFO ] listening to port 3389 on 0.0.0.0
[20211103-08:20:09] [INFO ] xrdp_listen_pp done
[20211103-08:20:34] [INFO ] Socket 12: AF_INET6 connection received from ::ffff:192.168.0.139 port 42446
[20211103-08:20:34] [DEBUG] Closed socket 12 (AF_INET6 ::ffff:192.168.0.176 port 3389)
[20211103-08:20:34] [DEBUG] Closed socket 11 (AF_INET6 :: port 3389)
[20211103-08:20:34] [INFO ] Using default X.509 certificate: /etc/xrdp/cert.pem
[20211103-08:20:34] [INFO ] Using default X.509 key file: /etc/xrdp/key.pem
[20211103-08:20:34] [DEBUG] TLSv1.3 enabled
[20211103-08:20:34] [DEBUG] TLSv1.2 enabled
[20211103-08:20:34] [DEBUG] Security layer: requested 3, selected 1
[20211103-08:20:40] [INFO ] connected client computer name: ViaLactea
[20211103-08:20:40] [INFO ] adding channel item name rdpdr chan_id 1004 flags 0xc0800000
[20211103-08:20:40] [INFO ] adding channel item name rdpsnd chan_id 1005 flags 0xc0000000
[20211103-08:20:40] [INFO ] adding channel item name cliprdr chan_id 1006 flags 0xc0a00000
[20211103-08:20:40] [INFO ] adding channel item name drdynvc chan_id 1007 flags 0xc0800000
[20211103-08:20:41] [INFO ] TLS connection established from ::ffff:192.168.0.139 port 42446: TLSv1.3 with cipher TLS_AES_256_GCM_SHA384
[20211103-08:20:41] [DEBUG] xrdp_0000097f_wm_login_mode_event_00000001
[20211103-08:20:41] [INFO ] Loading keymap file /etc/xrdp/km-0000080a.ini
[20211103-08:20:41] [WARN ] local keymap file for 0x0000080a found and doesn't match built in keymap, using local keymap file
[20211103-08:20:41] [DEBUG] xrdp_wm_log_msg: connecting to sesman ip 127.0.0.1 port 3350
[20211103-08:20:42] [INFO ] xrdp_wm_log_msg: sesman connect ok
[20211103-08:20:42] [DEBUG] xrdp_wm_log_msg: sending login info to session manager, please wait...
[20211103-08:20:42] [DEBUG] return value from xrdp_mm_connect 0
[20211103-08:20:43] [INFO ] xrdp_wm_log_msg: login failed for display 0
[20211103-08:20:43] [DEBUG] xrdp_mm_module_cleanup
[20211103-08:20:43] [DEBUG] Closed socket 18 (AF_INET6 ::1 port 33606)
[20211103-08:20:52] [DEBUG] xrdp_wm_log_msg: connecting to sesman ip 127.0.0.1 port 3350
[20211103-08:20:52] [INFO ] xrdp_wm_log_msg: sesman connect ok
[20211103-08:20:52] [DEBUG] xrdp_wm_log_msg: sending login info to session manager, please wait...
[20211103-08:20:52] [DEBUG] return value from xrdp_mm_connect 0
[20211103-08:20:53] [INFO ] xrdp_wm_log_msg: login successful for display 11
[20211103-08:20:53] [DEBUG] xrdp_wm_log_msg: started connecting
[20211103-08:20:53] [INFO ] lib_mod_log_peer: xrdp_pid=2431 connected to X11rdp_pid=2434 X11rdp_uid=1000 X11rdp_gid=1001 client_ip=::ffff:192.168.0.139 client_port=42446
[20211103-08:20:53] [DEBUG] xrdp_wm_log_msg: connected ok
[20211103-08:20:54] [DEBUG] xrdp_mm_connect_chansrv: chansrv connect successful
[20211103-08:20:54] [DEBUG] Closed socket 18 (AF_INET6 ::1 port 33608)
[20211103-08:20:55] [DEBUG] Closed socket 12 (AF_INET6 ::ffff:192.168.0.176 port 3389)
[20211103-08:20:55] [DEBUG] xrdp_mm_module_cleanup
[20211103-08:20:55] [DEBUG] Closed socket 19 (AF_UNIX)
[20211103-08:20:55] [DEBUG] Closed socket 20 (AF_UNIX)

On the last connection attempt (at the time of writing), via tail -200 /var/log/xrdp-sesman.log. Note that ... created session (access granted): username user1... suggests username/password are ok.

[20211103-08:20:06] [INFO ] shutting down sesman 1
[20211103-08:20:06] [DEBUG] Closed socket 7 (AF_INET6 ::1 port 3350)
[20211103-08:20:06] [DEBUG] libscp initialized
[20211103-08:20:06] [DEBUG] Testing if xrdp-sesman can listen on 127.0.0.1 port 3350.
[20211103-08:20:06] [DEBUG] Closed socket 5 (AF_INET6 ::1 port 3350)
[20211103-08:20:06] [INFO ] starting xrdp-sesman with pid 2420
[20211103-08:20:06] [INFO ] listening to port 3350 on 127.0.0.1
[20211103-08:20:41] [INFO ] A connection received from ::1 port 33606
[20211103-08:20:43] [DEBUG] Closed socket 8 (AF_INET6 ::1 port 3350)
[20211103-08:20:52] [INFO ] A connection received from ::1 port 33608
[20211103-08:20:52] [INFO ] ++ created session (access granted): username user1, ip ::ffff:192.168.0.139:42446 - socket: 12
[20211103-08:20:52] [INFO ] starting Xorg session...
[20211103-08:20:52] [DEBUG] Closed socket 9 (AF_INET6 :: port 5910)
[20211103-08:20:52] [ERROR] g_tcp_bind(9, 6010) failed bind IPv6 (errno=98) and IPv4 (errno=22).
[20211103-08:20:52] [DEBUG] Closed socket 9 (AF_INET6 :: port 0)
[20211103-08:20:52] [DEBUG] Closed socket 9 (AF_INET6 :: port 5911)
[20211103-08:20:52] [DEBUG] Closed socket 9 (AF_INET6 :: port 6011)
[20211103-08:20:52] [DEBUG] Closed socket 9 (AF_INET6 :: port 6211)
[20211103-08:20:53] [DEBUG] Closed socket 8 (AF_INET6 ::1 port 3350)
[20211103-08:20:53] [INFO ] calling auth_start_session from pid 2432
[20211103-08:20:53] [DEBUG] Closed socket 7 (AF_INET6 ::1 port 3350)
[20211103-08:20:53] [DEBUG] Closed socket 8 (AF_INET6 ::1 port 3350)
[20211103-08:20:53] [INFO ] /usr/lib/xorg/Xorg :11 -auth .Xauthority -config xrdp/xorg.conf -noreset -nolisten tcp -logfile .xorgxrdp.%s.log  
[20211103-08:20:53] [CORE ] waiting for window manager (pid 2433) to exit
[20211103-08:20:55] [CORE ] window manager (pid 2433) did exit, cleaning up session
[20211103-08:20:55] [INFO ] calling auth_stop_session and auth_end from pid 2432
[20211103-08:20:55] [DEBUG] cleanup_sockets:
[20211103-08:20:55] [DEBUG] cleanup_sockets: deleting /run/xrdp/sockdir/xrdp_chansrv_audio_out_socket_11
[20211103-08:20:55] [DEBUG] cleanup_sockets: deleting /run/xrdp/sockdir/xrdp_chansrv_audio_in_socket_11
[20211103-08:20:55] [DEBUG] cleanup_sockets: deleting /run/xrdp/sockdir/xrdpapi_11
[20211103-08:20:55] [INFO ] ++ terminated session:  username user1, display :11.0, session_pid 2432, ip ::ffff:192.168.0.139:42446 - socket: 12

On the Window Manager.

1. From a graphical terminal at the server.

    $ wmctrl -m
    Name: Openbox
    Class:
    PID: N/A
    Window manager's "showing the desktop" mode: OFF
   

2. From a graphical terminal at an ssh-logged client.

    $ wmctrl -m
    Name: GNOME Shell
    Class: N/A
    PID: N/A
    Window manager's "showing the desktop" mode: OFF
   

Excerpt from ~/.xsession-errors (at the time of writing)

Xsession: X session started for user1 at mié 03 nov 2021 10:33:01 -03
dbus-update-activation-environment: systemd --user not found, ignoring --systemd argument
dbus-update-activation-environment: setting DISPLAY=:11.0
localuser:user1 being added to access control list
dbus-update-activation-environment: systemd --user not found, ignoring --systemd argument
dbus-update-activation-environment: setting QT_ACCESSIBILITY=1
dbus-update-activation-environment: systemd --user not found, ignoring --systemd argument
dbus-update-activation-environment: setting USER=user1

Excerpt from ~/.xorgxrdp.11.log (at the time of writing, checked based on this)

[ 10692.409] (EE) systemd-logind: failed to take device /dev/dri/card0: Operation not permitted
[ 10692.409] (EE) /dev/dri/card0: failed to set DRM interface version 1.4: Permission denied

Related

1. https://aguslr.com/blog/2017/04/15/debian-thinclient.html
2. https://thunderboltlaptop.com/install-xrdp-ubuntu/
3. Openbox vs. LXQt

I am inexperienced in configuring mail systems. I am using Ubuntu #54~20.04.1-Ubuntu.

How can I configure my computer to send emails using a gmail account, with postfix?
I mean not to have any other paid mail server or domain involved (EDIT: I could configure my PC to work as a server, but I mean to avoid requiring paid registration in DNSs). Is this is even possible?

I tried a few things, which I will describe below, citing the sources I used.
I have read other sources, but I could not figure out what to do. As I understand, most of these other sources assume I have some other server or address I can use (typically exemplified as example.com), which I don't have, and I guess I can dispense with.

1. I followed this basic guide, which seemed to be useful for many others. After issuing

   echo "Test mail thingy" | mail -s "Test Postfix Subject" [email protected]
   

   I did not get an email in [email protected], and this is the relevant tail of /var/log/mail.log (line numbers added for reference)

    1 Apr 18 08:55:03 MyComputer postfix/postfix-script[1092678]: refreshing the Postfix mail system
    2 Apr 18 08:55:03 MyComputer postfix/master[3124]: reload -- version 3.4.13, configuration /etc/postfix
    3 Apr 18 08:55:24 MyComputer postfix/pickup[1092682]: 06004443921: uid=1000 from=<MyUser@MyComputer>
    4 Apr 18 08:55:24 MyComputer postfix/cleanup[1092704]: 06004443921: message-id=<[email protected]_URL>
    5 Apr 18 08:55:24 MyComputer postfix/qmgr[1092683]: 06004443921: from=<MyUser@MyComputer>, size=391, nrcpt=1 (queue active)
    6 Apr 18 08:55:24 MyComputer postfix/error[1092706]: 06004443921: to=<[email protected]>, relay=none, delay=0.03, delays=0.02/0/0/0.01, dsn=5.0.0, status=bounced ([smtp.gmail.com]:587)
    7 Apr 18 08:55:24 MyComputer postfix/cleanup[1092704]: 09DD4443938: message-id=<[email protected]_URL>
    8 Apr 18 08:55:24 MyComputer postfix/bounce[1092707]: 06004443921: sender non-delivery notification: 09DD4443938
    9 Apr 18 08:55:24 MyComputer postfix/qmgr[1092683]: 09DD4443938: from=<>, size=2359, nrcpt=1 (queue active)
   10 Apr 18 08:55:24 MyComputer postfix/qmgr[1092683]: 06004443921: removed
   11 Apr 18 08:55:24 MyComputer postfix/local[1092708]: 09DD4443938: to=<MyUser@MyComputer>, relay=local, delay=0.01, delays=0/0/0/0, dsn=2.0.0, status=sent (delivered to mailbox)
   12 Apr 18 08:55:24 MyComputer postfix/qmgr[1092683]: 09DD4443938: removed
   

   I don't know how to interpret this log. I note that line 11 states status=sent.

2. I added -a "From: [email protected]" (ref). I did not get the mail either. Lines in /var/log/mail.log that changed as compared to above are marked with *. Now I have status=bounced in line 11.

    3*Apr 18 09:54:43 MyComputer postfix/pickup[1098199]: 0353244348F: uid=1000 from=<[email protected]>   <-- CHANGED
    4 Apr 18 09:54:43 MyComputer postfix/cleanup[1098387]: 0353244348F: message-id=<[email protected]_URL>
    5*Apr 18 09:54:43 MyComputer postfix/qmgr[1098200]: 0353244348F: from=<[email protected]>, size=384, nrcpt=1 (queue active)   <-- CHANGED
    6 Apr 18 09:54:43 MyComputer postfix/error[1098389]: 0353244348F: to=<[email protected]>, relay=none, delay=0.03, delays=0.02/0/0/0, dsn=5.0.0, status=bounced ([smtp.gmail.com]:587)
    7 Apr 18 09:54:43 MyComputer postfix/cleanup[1098387]: 06E2F4436C3: message-id=<[email protected]_URL>
    8 Apr 18 09:54:43 MyComputer postfix/bounce[1098390]: 0353244348F: sender non-delivery notification: 06E2F4436C3
    9 Apr 18 09:54:43 MyComputer postfix/qmgr[1098200]: 06E2F4436C3: from=<>, size=2364, nrcpt=1 (queue active)
   10 Apr 18 09:54:43 MyComputer postfix/qmgr[1098200]: 0353244348F: removed
   11*Apr 18 09:54:43 MyComputer postfix/error[1098389]: 06E2F4436C3: to=<[email protected]>, relay=none, delay=0.01, delays=0/0/0/0, dsn=5.0.0, status=bounced ([smtp.gmail.com]:587)   <-- CHANGED
   12 Apr 18 09:54:43 MyComputer postfix/qmgr[1098200]: 06E2F4436C3: removed
   

Notes:

1. Prior to my attempts today, I already had postfix installed. I do not recall when and why I installed it. I do not recall either going through the postfix configuration screen. I know I can do it with sudo dpkg-reconfigure postfix, but I don't know which is the proper option.

2. This adds smtp_tls_CAfile = /etc/postfix/cacert.pem to /etc/postfix/main.cf, instead of smtp_tls_CApath ..., and later cats a specific .pem to cacert.pem. I don't have cacert.pem. I guess both options can work if properly configured.

3. I have lots of soft links in /etc/ssl/certs/. I am not sure I need to add anything.

4. I used my actual source gmail and corresponding password in /etc/postfix/sasl_passwd.

Related:

1. How can I configure postfix to send emails via gmail (2FA problems)?
2. SETUP for sending Mail via postfix to GMAIL to use ssmtp instead of postfix.
3. Setting gmail as default for sending files via email using gnome-gmail or desktop-webmail.
4. https://rtcamp.com/tutorials/linux/ubuntu-postfix-gmail-smtp/
5. Sending email from Gmail account to local Ubuntu server
6. Ubuntu 20.04 Mail Setup Setting the Default From Address
7. https://www.digitalocean.com/community/tutorials/how-to-install-and-configure-postfix-as-a-send-only-smtp-server-on-ubuntu-18-04
8. https://www.digitalocean.com/community/tutorials/how-to-install-and-configure-postfix-on-ubuntu-20-04
9. https://www.linuxbabe.com/mail-server/setup-basic-postfix-mail-sever-ubuntu
10. https://www.cyberciti.biz/faq/how-to-configure-postfix-relayhost-smarthost-to-send-email-using-an-external-smptd/
11. https://ubuntu.com/server/docs/mail-postfix
12. https://devops.ionos.com/tutorials/configure-a-postfix-relay-through-gmail-on-ubuntu/

When starting Eclipse for the first time in my Ubuntu 20.04, I got a warning (which actually seem to be 2 warnings)

***WARNING: Detected: GTK_IM_MODULE=xim. This input method is unsupported and can cause graphical issues.
***WARNING: Unset GTK_IM_MODULE or set GTK_IM_MODULE=ibus if flicking is experienced. 
log4j:WARN No appenders could be found for logger (org.eclipse.jgit.internal.storage.file.FileSnapshot).
log4j:WARN Please initialize the log4j system properly.

To deal with the GTK... warning, I googled a bit. I found here that "Gnome made ibus the default input method" (even if the answer is from 2016, figure below suggests it still applies). But

$ env | grep -i gtk
GTK_IM_MODULE=xim
GTK_MODULES=gail:atk-bridge

So I wonder where is GTK_IM_MODULE set. What I tried (with no luck):

$ grep -i gtk ~/.bashrc
$ grep -i gtk ~/.profile 
$ grep -i gtk /etc/profile
$ grep -i -nH gtk /etc/profile.d/*
$ grep -i gtk ~/.xprofile 
$ grep -i gtk ~/.xinputrc 
$ gsettings get org.gnome.desktop.interface gtk-im-module
'gtk-im-context-simple'

(note that as per dconf-editor, the default value is '').

I will next try the suggestion in the warning, Unset GTK_IM_MODULE or set GTK_IM_MODULE=ibus, but I still have the question:

Where are GTK_IM_MODULE and GTK_MODULES set?

When launching im-config I see this

EDIT:

Perhaps ~/.xinputrc is responsible. Its contents:

# im-config(8) generated on Tue, 03 Nov 2020 10:36:11 -0300
run_im xim
# im-config signature: 1f92fadecc95eaeaf5534ec0902b5a9b  -

If this is the cause, why would .xinputrc contain that?

EDIT #2:

I have removed .xinputrc, logged out and in again. Still

$ env | grep -i gtk
GTK_IM_MODULE=xim
GTK_MODULES=gail:atk-bridge

So it seems .xinputrc was not the culprit.

EDIT #3:

I executed

$ im-config -n ibus
$ im-config -m
default
ibus
ibus

ibus

So I made sure ibus was current (in the second line of the output, I had xim before). I logged out and in again. Still

$ env | grep -i gtk
GTK_IM_MODULE=xim
GTK_MODULES=gail:atk-bridge
$ cat .xinputrc 
# im-config(8) generated on Thu, 04 Mar 2021 23:34:26 -0300
run_im ibus
# im-config signature: 3d5777226bbd6243ce412ee4470b8020  -

Plus, launching eclipse still gives the same warning (expected, since the environment variables have the same values). And the ensuing flicker is still present.

As requested in comments

$ env | grep -E '_IM|XMOD'
GTK_IM_MODULE=xim
QT4_IM_MODULE=xim
XMODIFIERS=@im=none
CLUTTER_IM_MODULE=xim
QT_IM_MODULE=ibus

So it seems .xinputrc was not the culprit.

EDIT #4:

After a reboot

$ im-config -m
default
ibus
ibus

ibus
$ env | grep -E '_IM|XMOD'
XMODIFIERS=@im=ibus
QT_IM_MODULE=ibus
$ env | grep -i gtk
GTK_MODULES=gail:atk-bridge
$ grep -i gtk ~/.profile 
$ grep -i gtk /etc/environment
$ grep -i gtk /etc/environment.d/*
/etc/environment.d/90atk-adaptor.conf:GTK_MODULES=${GTK_MODULES:+$GTK_MODULES:}gail:atk-bridge

Plus, eclipse does not show the warning (as expected), and the flicker is gone.

whether GTK_IM_MODULE was also set in /etc/environment.d/90atk-adaptor.conf, I cannot tell (I would need to try a few things to ascertain that).

Even if not needed:

1. The question about what set GTK_IM_MODULE persists.
2. I will try removing .xinputrc, rebooting, and checking again.

This is yet another question regarding the error message E: Failed to fetch ... (example in Note 2 below). What makes this question different (I guess) from the others I have seen is the following.

I am running Ubuntu 18.04LTS, behind a proxy. I had a lot of packages with available updates (more than 200, I guess).

I could update many of the packages with no problem, and I ended up with 48 that I cannot install.

All of the packages not installed belong to bionic-updates/universe or bionic-updates/main. And most are related to java, jdk, linux, systemd. The complete list is in Note 1 below. But there are packages from bionic-updates/universe and bionic-updates/main that I can install (I just installed qemu and bsdutils).

How is it possible that some of the packages can be installed and some cannot?
What is a possible solution (other than connecting the PC without a proxy)?

Notes:

1. Complete list of packages not installed

   ant ant-optional apport apport-gtk fwupd fwupdate fwupdate-signed gettext gettext-base jarwrapper junit4 libasm-java libcommons-collections3-java libcommons-compress-java libcommons-httpclient-java libdb5.3 libdb5.3-java libdb5.3-java-jni libecj-java libequinox-osgi-java libhsqldb1.8.0-java libjetty9-java libnss-systemd libobjenesis-java libpam-systemd libservlet3.1-java libsystemd0 libtomcat8-java linux-generic linux-headers-generic linux-image-generic openjdk-11-jdk openjdk-11-jdk-headless openjdk-11-jre openjdk-11-jre-headless openjdk-8-jdk openjdk-8-jdk-headless openjdk-8-jre openjdk-8-jre-headless python-pip-whl python3-pip snapd systemd
   

This was obtained with

$ sudo apt list --upgradable 2> /dev/null | sed 's/\/.*//' | tail +2 | sed -e ':a' -e 'N' -e '$!ba' -e 's/\n/ /g'

To find which repo each one belonged, I used (printf "%30s"... helps visualizing in columns)

$ for p in $(sudo apt list --upgradable 2> /dev/null | sed 's/\/.*//' | tail +2 | sed -e ':a' -e 'N' -e '$!ba' -e 's/\n/ /g') ; do printf "%30s" $p ; apt policy $p 2> /dev/null | tail +6 | head -1 ; done

This generates output like

                       ant        500 http://us.archive.ubuntu.com/ubuntu bionic-updates/universe amd64 Packages

2. Sample error

    $ sudo apt-get install apport
    Reading package lists... Done
    Building dependency tree       
    Reading state information... Done
    The following packages will be upgraded:
      apport
    1 upgraded, 0 newly installed, 0 to remove and 46 not upgraded.
    Need to get 125 kB of archives.
    After this operation, 20,5 kB of additional disk space will be used.
    Ign:1 http://us.archive.ubuntu.com/ubuntu bionic-updates/main amd64 apport all 2.20.9-0ubuntu7.17
    Err:1 http://us.archive.ubuntu.com/ubuntu bionic-updates/main amd64 apport all 2.20.9-0ubuntu7.17
      403  URLBlockDownload [IP: xxx.xxx.xxx3.xxx 80]
    E: Failed to fetch http://us.archive.ubuntu.com/ubuntu/pool/main/a/apport/apport_2.20.9-0ubuntu7.17_all.deb  403  URLBlockDownload [IP: 10.1.33.101 80]
    E: Unable to fetch some archives, maybe run apt-get update or try with --fix-missing?

3. EDIT: output "requested" in this answer is here.

    $ find /etc/apt/ -name "*.list" -exec grep -iq http {} \; -exec egrep -v '^#|^$' {} \; | uniq 
    deb [arch=amd64] http://dl.google.com/linux/chrome/deb/ stable main
    deb http://us.archive.ubuntu.com/ubuntu/ bionic main restricted
    deb http://us.archive.ubuntu.com/ubuntu/ bionic-updates main restricted
    deb http://us.archive.ubuntu.com/ubuntu/ bionic universe
    deb http://us.archive.ubuntu.com/ubuntu/ bionic-updates universe
    deb http://us.archive.ubuntu.com/ubuntu/ bionic multiverse
    deb http://us.archive.ubuntu.com/ubuntu/ bionic-updates multiverse
    deb http://us.archive.ubuntu.com/ubuntu/ bionic-backports main restricted universe multiverse
    deb http://security.ubuntu.com/ubuntu bionic-security main restricted
    deb http://security.ubuntu.com/ubuntu bionic-security universe
    deb http://security.ubuntu.com/ubuntu bionic-security multiverse
    deb https://apt.kitware.com/ubuntu/ bionic main

I had this issue with sound Only "Dummy output" (sound) in Ubuntu 20.04 after reboot - Broken driver / module after a reboot. I was missing package linux-modules-extra-5.4.0-40-generic.

Now I rebooted again (I am not sure think I know if I also rebooted at some point in between), and I had no sound or wifi. I checked and now I have kernel 5.4.0-42.46, and I didn't have linux-modules-extra-5.4.0-42-generic. So I guessed there was an automatic kernel update (I don't recall doing it myself), without installing that package, waiting for me to reboot and suffer from the missing package.

My questions are:

1. Why would an automatic kernel update not install linux-modules-extra?
2. Can I configure my system to have the package installed whenever an update takes place?

Related:

Kernel modules missing after update to 5.4.0-37

What is the linux-image-extra package for and do I need it?

I often use

du --max-depth=n -h | sort --human-numeric-sort

Now I want to use tree, in a similar manner. I found here a partial answer

tree -sh --sort=size --du

where --du makes tree reporting the cumulative size for each directory (as du). This reports each file as well. If I want to report only directories, I should add -d to tree. But -d seems to do two things:

1. Remove files from the report.
2. Remove the size of files from the cumulative total computed for each dir.

Of course, I want only 1, not 2 (as du does). So

tree -sh --sort=size --du -d

would always report "small" sizes, without considering file sizes.

Can tree overcome this? Is there any alternative?

EDIT: This appears to have turned in a sort of canonical set of commands to start diagnosing audio issues.

I am using Ubuntu 20.04 for over a month now. After a reboot, I have no more sound and WiFi. Note that this is different from many other posts, which seem to have had no sound at all, after an upgrade. In this case, sound stopped working only after a reboot.

As for the sound, I seem to not have the appropriate kernel modules for sound, so I guess the most likely solution would come from making the modules available (it seems I have two sound cards). I will try to include below (1) as much info as possible related to the copious posts with similar problems.

I am listing below (2) the posts that I consider most useful at the current point of the fixing work-in-progress.

And I am listing below (3) other posts that I checked when the grass was higher.

(1) Info about my broken system, along with a comparison with what I see in a working system that I managed to put together.

1. No /proc/asound directory.
   Versus

    $ cat /proc/asound/cards
     0 [PCH            ]: HDA-Intel - HDA Intel PCH
                          HDA Intel PCH at 0x604b108000 irq 159
     1 [NVidia         ]: HDA-Intel - HDA NVidia
                          HDA NVidia at 0xa4000000 irq 17

2. $ lsmod | grep snd outputs nothing.
   Versus (also compare with this)

    $ lsmod | grep snd_hda_intel
    snd_hda_intel          53248  10
    snd_intel_dspcfg       24576  3 snd_hda_intel,snd_sof_pci,snd_sof_intel_hda_common
    snd_hda_codec         131072  5 snd_hda_codec_generic,snd_hda_codec_hdmi,snd_hda_intel,snd_hda_codec_realtek,snd_soc_hdac_hda
    snd_hda_core           90112  9 snd_hda_codec_generic,snd_hda_codec_hdmi,snd_hda_intel,snd_hda_ext_core,snd_hda_codec,snd_hda_codec_realtek,snd_sof_intel_hda_common,snd_soc_hdac_hda,snd_sof_intel_hda
    snd_pcm               106496  9 snd_hda_codec_hdmi,snd_hda_intel,snd_hda_codec,snd_sof,snd_sof_intel_hda_common,snd_soc_core,snd_hda_core,snd_pcm_dmaengine
    snd                    90112  33 snd_hda_codec_generic,snd_seq,snd_seq_device,snd_hda_codec_hdmi,snd_hwdep,snd_hda_intel,snd_hda_codec,snd_hda_codec_realtek,snd_timer,snd_compress,thinkpad_acpi,snd_soc_core,snd_pcm,snd_rawmidi

3. Kernel modules

    $ dpkg -L linux-modules-$(uname -r) | grep snd
    /lib/modules/5.4.0-40-generic/kernel/sound/core/seq/snd-seq-dummy.ko
    /lib/modules/5.4.0-40-generic/kernel/sound/core/seq/snd-seq-midi-emul.ko
    /lib/modules/5.4.0-40-generic/kernel/sound/core/seq/snd-seq-midi-event.ko
    /lib/modules/5.4.0-40-generic/kernel/sound/core/seq/snd-seq-midi.ko
    /lib/modules/5.4.0-40-generic/kernel/sound/core/seq/snd-seq-virmidi.ko
    /lib/modules/5.4.0-40-generic/kernel/sound/core/seq/snd-seq.ko
    /lib/modules/5.4.0-40-generic/kernel/sound/core/snd-compress.ko
    /lib/modules/5.4.0-40-generic/kernel/sound/core/snd-hrtimer.ko
    /lib/modules/5.4.0-40-generic/kernel/sound/core/snd-hwdep.ko
    /lib/modules/5.4.0-40-generic/kernel/sound/core/snd-pcm-dmaengine.ko
    /lib/modules/5.4.0-40-generic/kernel/sound/core/snd-pcm.ko
    /lib/modules/5.4.0-40-generic/kernel/sound/core/snd-rawmidi.ko
    /lib/modules/5.4.0-40-generic/kernel/sound/core/snd-seq-device.ko
    /lib/modules/5.4.0-40-generic/kernel/sound/core/snd-timer.ko
    /lib/modules/5.4.0-40-generic/kernel/sound/core/snd.ko
    /lib/modules/5.4.0-40-generic/kernel/sound/drivers/pcsp/snd-pcsp.ko
    /lib/modules/5.4.0-40-generic/kernel/sound/pci/snd-ens1370.ko

Versus exactly the same

How can I check if any of this is what I need?
How can I check if any of this corresponds to those from Intel listed in item #2 above?
How can I load these modules?

4. inxi

    $ inxi -SA
    System:    Host: Hydrus1 Kernel: 5.4.0-40-generic x86_64 bits: 64 Desktop: Gnome 3.36.1 Distro: Ubuntu 20.04 LTS (Focal Fossa) 
    Audio:     Device-1: Intel 6 Series/C200 Series Family High Definition Audio driver: N/A 
               Device-2: NVIDIA GF104 High Definition Audio driver: N/A 

Versus (also compare with this)

    $ inxi -SA
    System:    Host: ViaLactea Kernel: 5.4.0-40-generic x86_64 bits: 64 Console: tty 0 Distro: Ubuntu 20.04 LTS (Focal Fossa)
    Audio:     Device-1: Intel Cannon Lake PCH cAVS driver: snd_hda_intel
               Device-2: NVIDIA GP107GL High Definition Audio driver: snd_hda_intel
               Sound Server: ALSA v: k5.4.0-40-generic

5. lspci

   $ lspci -nnk | grep -A 1 Audio
   00:1b.0 Audio device [0403]: Intel Corporation 6 Series/C200 Series Chipset Family High Definition Audio Controller [8086:1c20] (rev 04)
       DeviceName:  Onboard Audio
       Subsystem: Dell 6 Series/C200 Series Chipset Family High Definition Audio Controller [1028:04a4]
   00:1c.0 PCI bridge [0604]: Intel Corporation 6 Series/C200 Series Chipset Family PCI Express Root Port 1 [8086:1c10] (rev b4)
   --
   01:00.1 Audio device [0403]: NVIDIA Corporation GF104 High Definition Audio Controller [10de:0beb] (rev a1)
       Subsystem: Dell GF104 High Definition Audio Controller [1028:04a4]
   03:00.0 Network controller [0280]: Intel Corporation Centrino Ultimate-N 6300 [8086:422b] (rev 35)
   

Versus

    $ lspci -nnk | grep -n -A 4 Audio
    49:00:1f.3 Audio device [0403]: Intel Corporation Cannon Lake PCH cAVS [8086:a348] (rev 10)
    50-     Subsystem: Lenovo Cannon Lake PCH cAVS [17aa:225f]
    51-     Kernel driver in use: snd_hda_intel
    52-     Kernel modules: snd_hda_intel, snd_sof_pci
    53-00:1f.4 SMBus [0c05]: Intel Corporation Cannon Lake PCH SMBus Controller [8086:a323] (rev 10)
    --
    67:01:00.1 Audio device [0403]: NVIDIA Corporation GP107GL High Definition Audio Controller [10de:0fb9] (rev a1)
    68-     Kernel driver in use: snd_hda_intel
    69-     Kernel modules: snd_hda_intel
    70-70:00.0 Unassigned class [ff00]: Realtek Semiconductor Co., Ltd. RTS525A PCI Express Card Reader [10ec:525a] (rev 01)
    71-     Subsystem: Lenovo RTS525A PCI Express Card Reader [17aa:225f]

6. System (Versus exactly the same kernel)

   $ uname -a
   Linux Hydrus1 5.4.0-40-generic #44-Ubuntu SMP Tue Jun 23 00:01:04 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux
   

7. Test sound

   $ aplay -l
   aplay: device_list:274: no soundcards found...
   

Versus

    $ aplay -l
    **** List of PLAYBACK Hardware Devices ****
    card 0: PCH [HDA Intel PCH], device 0: ALC285 Analog [ALC285 Analog]
      Subdevices: 0/1
      Subdevice #0: subdevice #0
    card 0: PCH [HDA Intel PCH], device 3: HDMI 0 [HDMI 0]
      Subdevices: 1/1
      Subdevice #0: subdevice #0
    ...

8. lshw

        $ lshw -C multimedia
        WARNING: you should run this program as super-user.
          *-multimedia UNCLAIMED    
               description: Audio device
               product: GF104 High Definition Audio Controller
               vendor: NVIDIA Corporation
               physical id: 0.1
               bus info: pci@0000:01:00.1
               version: a1
               width: 32 bits
               clock: 33MHz
               capabilities: bus_master cap_list
               configuration: latency=0
               resources: memory:e0080000-e0083fff
          *-multimedia UNCLAIMED
               description: Audio device
               product: 6 Series/C200 Series Chipset Family High Definition Audio Controller
               vendor: Intel Corporation
               physical id: 1b
               bus info: pci@0000:00:1b.0
               version: 04
               width: 64 bits
               clock: 33MHz
               capabilities: bus_master cap_list
               configuration: latency=0
               resources: memory:e1e50000-e1e53fff
        WARNING: output may be incomplete or inaccurate, you should run this program as super-user.

Here it is quoted (note the driver)

    $ sudo lshw -C multimedia
      *-multimedia              
           description: Audio device
           product: GP104 High Definition Audio Controller
           vendor: NVIDIA Corporation
           physical id: 0.1
           bus info: pci@0000:01:00.1
           version: a1
           width: 32 bits
           clock: 33MHz
           capabilities: pm msi pciexpress bus_master cap_list
           configuration: driver=snd_hda_intel latency=0
           resources: irq:17 memory:f7080000-f7083fff

9. alsa packages

   $ dpkg -l | grep alsa
   ii  alsa-base                                     1.0.25+dfsg-0ubuntu5                all          ALSA driver configuration files
   ii  alsa-tools-gui                                1.1.7-1ubuntu1                      amd64        GUI based ALSA utilities for specific hardware
   ii  alsa-topology-conf                            1.2.2-1                             all          ALSA topology configuration files
   ii  alsa-ucm-conf                                 1.2.2-1ubuntu0.1                    all          ALSA Use Case Manager configuration files
   ii  alsa-utils                                    1.2.2-1ubuntu1                      amd64        Utilities for configuring and using ALSA
   ii  gstreamer1.0-alsa:amd64                       1.16.2-4                            amd64        GStreamer plugin for ALSA
   ii  libsox-fmt-alsa:amd64                         14.4.2+git20190427-2                amd64        SoX alsa format I/O library
   

10. No sound either if I plug earphones.

11. I have no timidity-daemon to remove.

12. Attempt reload

    $ sudo alsa force-reload
    [sudo] password for user1: 
    Unloading ALSA sound driver modules: (none loaded).
    Loading ALSA sound driver modules: (none to reload).
    

13. modprobe

    $ grep intel /etc/modprobe.d/alsa-base.conf 
    options snd-intel8x0m index=-2
    

(2) Related and possibly useful posts

Unable to get sound working. Ubuntu Server 14.04.3

https://forums.linuxmint.com/viewtopic.php?t=221745

https://ubuntuforums.org/showthread.php?t=1684576

How to load "snd-hda-intel" at startup

(3) Other related posts

https://www.alsa-project.org/wiki/Matrix:Module-hda-intel

https://askubuntu.com/a/1244118/226614 . Recent post, accepted answer. Suggests using a ppa for fixing. I am not sure this can get things worse...

https://askubuntu.com/a/1249071/226614 . Recent post. Suggests using sudo setfacl -m u:user1:rw /dev/snd/* Tried this, didn't help.

https://askubuntu.com/a/847954/226614 . Old post, accepted answer. Suggests installing alsa-firmware-loaders and alsa-base. I am not sure this still applies...

How to install missing firmware for an Creative Labs Audigy2 soundcard? . Also old post. Also suggests UNCLAIMED device is due to firmware issues. Why would the problem appear after a reboot?

No sound on upgrade (18.04 -> 20.04) only have "dummy output"

Dummy output after standby since upgrading to Ubuntu 20.04

Internal speaker (Audio) is not working in Ubuntu 20.04 LTS after upgrading from Ubuntu 18.04 LTS

Ubuntu 20.04 - No sound

Soundcard not detected by pulseaudio (but by alsa)

How to install missing firmware for an Creative Labs Audigy2 soundcard?

https://itsfoss.com/fix-sound-ubuntu-1304-quick-tip/

I mean to install scanner Epson 3170 Photo under Ubuntu 20.04. I post at the bottom the (usual) installation steps I took prior to checking if my PC finds the scanner.

Then, sane-find-scanner found the scanner

$ sudo sane-find-scanner

  # sane-find-scanner will now attempt to detect your scanner. If the
  # result is different from what you expected, first make sure your
  # scanner is powered up and properly connected to your computer.

  # No SCSI scanners found. If you expected something different, make sure that
  # you have loaded a kernel SCSI driver for your SCSI adapter.

found USB scanner (vendor=0x06cb, product=0x009a) at libusb:001:005
found USB scanner (vendor=0x04b8 [EPSON], product=0x0116 [EPSON Scanner]) at libusb:001:009
  # Your USB scanner was (probably) detected. It may or may not be supported by
  # SANE. Try scanimage -L and read the backend's manpage.

  # Not checking for parallel port scanners.

  # Most Scanners connected to the parallel port or other proprietary ports
  # can't be detected by this program.

Note: without sudo I got the error messages

could not open USB device 0x1d6b/0x0003 at 002:001: Access denied (insufficient permissions)
...

I mean to fix this later on, if I manage to overcome the following problems, unless this is part of the problem, which I guess it is not).

Then scanimage did not find the scanner

$ sudo scanimage -L

No scanners were identified. If you were expecting something different,
check that the scanner is plugged in, turned on and detected by the
sane-find-scanner tool (if appropriate). Please read the documentation
which came with this software (README, FAQ, manpages).

So I edited /etc/sane.d/dll.conf, to add epkowa (it wasn't listed), and comment epson2; epson was already commented. The page SANE: External Backends (Drivers) mentions that the 3170 is supported by epkowa ("requires DFSG non-free iscan-plugin-gt-9400 overseas version of the GT-9400UF").

So I tried installing iscan-plugin-gt-9400. It is only available as an rpm, not deb. Looking for related info, I found in [Solved] Successful Image Scan Installation for EPSON USB Scanner and Epson Perfection 3170 Photo Scanner (aka GT-9400) on Ubuntu Feisty that going through the conversion rpm -> deb and installing them (two packages, actually) is the only way to make the 3170 work. I am not certain this changed from the time of those posts, but I decided trying.

Following instructions above, and additionally:

1. Using Architecture: i386 amd64 instead of Architecture: i386, amd64 in debian/control files (otherwise error dpkg-gencontrol: error: 'i386,' is not a legal architecture in list 'i386, amd64' is thrown).

2. Executing export LD_LIBRARY_PATH="/usr/lib/x86_64-linux-gnu" since I was getting several errors

   $ fakeroot debian/rules binary
   ...
   dpkg-shlibdeps: error: cannot find library libjpeg.so.62 needed by debian/iscan/usr/lib/sane/libsane-epkowa.so.1.0.15 (ELF format: 'elf32-i386' abi: '0101000300000000'; RPATH: '')
   ...
   dpkg-shlibdeps: error: cannot continue due to the errors listed above
   Note: libraries are not searched in other binary packages that do not have any shlibs or symbols file.
   To help dpkg-shlibdeps find private libraries, you might need to use -l.
   dh_shlibdeps: error: dpkg-shlibdeps -Tdebian/iscan.substvars debian/iscan/usr/lib/sane/libsane-epkowa.so.1.0.15 debian/iscan/usr/lib/libesmod.so.1.1.0 debian/iscan/usr/bin/iscan returned exit code 2
   dh_shlibdeps: error: Aborting due to earlier error
   make: [debian/rules:27: binary-arch] Error 2 (ignored)
   ...
   

I managed to create iscan_2.10.0-2_amd64.deb (is it expected to get 2.10.0-2 instead of 2.10.0-1?) and iscan-plugin-gt-9400_1.0.0-2_amd64.deb.

Then I installed both packages with

$ sudo gdebi iscan_2.10.0-2_amd64.deb
$ sudo gdebi iscan-plugin-gt-9400_1.0.0-2_amd64.deb 

(I overwrote here my previously created /etc/sane.d/epkowa.conf).

Then I plugged the scanner and turned it on. And the I got error

$ iscan
iscan: error while loading shared libraries: libjpeg.so.62: wrong ELF class: ELFCLASS64

How can I proceed to get the scanner to work? (I expect once this problem is solved, there will be a few hurdles until it is working)

What I did:

1. sudo apt-get install sane sane-utils libsane xsane

2. Download imagescan-bundle-ubuntu-19.10-3.62.0.x64.deb.tar.gz

3. Expand archive above and inside imagescan-bundle-ubuntu-19.10-3.62.0.x64.deb execute ./install.sh

4. Add myself to group lp: sudo adduser $USER lp

5. Reboot

6. Verify

   $ groups
   user1 adm lp cdrom sudo dip plugdev lpadmin lxd sambashare vboxusers
   

7. Plug the scanner in the USB and turn it on.

Related

1. https://alicious.com/iscan-linux-networked-epson/
2. https://wiki.archlinux.org/index.php/SANE/Scanner-specific_problems#Epson
3. Running a epson Scanner perfection 3170
4. Syntax error when installing Epson Linux scanner driver (for v550)
5. https://bbs.archlinux.org/viewtopic.php?id=182346
6. Scanner Epson L210 for Ubuntu 16.04 is NOW working
7. https://exain.wordpress.com/tag/epkowa/
8. http://fbcorner.tuxfamily.org/linux.html
9. https://forums.linuxmint.com/viewtopic.php?t=279318
10. How to install EPSON l210 scanner
11. Simple Scan cannot find scanner
12. https://gist.github.com/unfulvio/e8daa0a78482a03e0358b0f5afee8b03
13. https://linux.die.net/man/7/sane
14. Scanner Not detected by Simple Scan
15. https://community.clearlinux.org/t/scanner-not-recognized-part-2/1719
16. http://manpages.ubuntu.com/manpages/bionic/man5/sane-epson2.5.html
17. http://www.subdude-site.com/WebPages_Local/RefInfo/Computer/Linux/ScannerHowTo/Scanner_HowTo_forEpson.htm
18. https://www.gsp.com/cgi-bin/man.cgi?section=5&topic=sane-epkowa

I have followed the instructions here (and posted many places else in various forms, 1) to boot from an iso image of Win10 under VBox in Ubuntu 20.04.

I get Fatal: Could not read from the boot medium! System halted

What am I missing?

Notes:

1. I actually posted first Install a guest Win10 in VirtualBox in Ubuntu 20.04 from USB. Since the difference between booting from a USB installer or an .iso image installer may be significant, I later changed the title of the other question to specifically address the USB case, and this one to address the .iso image case.

2. I managed to import the ova image obtained here, MSEdge - Win10.ova, but it is not the same.

I am looking for information on tracker, and generally speaking I find it very scarce.

In particular, is there any reference describing the possible configuration to set what tracker indexes?

I found here the following configuration options, but I don't know how/where to use them

-- enable-writeback false
-- index-optical-discs false
-- index-on-battery false
-- index-removable-devices false
-- ignored-directories ['core-dumps', 'CVS', 'lost+found', 'po', 'vendor']
-- ignore-stop-words true
-- ignore-numbers true
-- max-words-to-index 1000
-- removable-days-threshold 3 ? (I don't not understand this)

From The tracker FAQ:

How can I control what Tracker indexes?

In GNOME, you can use the Search Settings panel to control what Tracker indexes. See GNOME's documentation.

You can control Tracker's configuration directly using dconf-editor or the gsettings CLI tool. The relevant schemas are org.freedesktop.Tracker.Miner.Files and org.freedesktop.Tracker.Extract.

So I go to... GNOME's documentation:

Customize files search only describes how to control which files are indexed, not what is indexed.

I used to have a hierarchical menu at the top left, that let me launch applications, similar the old-fashioned Windows start menu. The nice thing about this is that one may organize the launchers, instead of having all at the same level, as in the Dock. In Unity, for instance, Drawers intended to allow for a similar capability.

How can I get this menu in Ubuntu 20?

I know I can simply search for an app in Activities. The menu I am referring to is not a replacement for that, but complementary. In this menu, I can explore what is available, in an organized manner.

Regarding configuration of Unattended-Upgrades:

1. Which are the appropriate files for configuring each option of Unattended-Upgrades?
   I have seen three files mentioned, see below. I am not certain others could also be used.

2. Can any of the files above be used for any of the options, or there is a restriction on this? (There is some overlap, for sure, see below).

3. Which has precedence for repeated options?

PS: These are actually different questions, but intimately related, so it would be possibly less convenient to separate them into different posts.

What I see in my 18.04LTS:

$ cat /etc/apt/apt.conf.d/20auto-upgrades 
APT::Periodic::Update-Package-Lists "1";
APT::Periodic::Unattended-Upgrade "1";
$ cat /etc/apt/apt.conf.d/10periodic 
APT::Periodic::Update-Package-Lists "1";
APT::Periodic::Download-Upgradeable-Packages "0";
APT::Periodic::AutocleanInterval "0";
$ cat /etc/apt/apt.conf.d/50unattended-upgrades
(long output)

PS2: As for how to configure or disable, these are related

Limiting the time Unattended-Upgrade keeps the lock on `/var/lib/dpkg/`

Ubuntu 16.04: Unattended-upgrades runs at random times

Unattended-upgrades running for hours

Disable automatic updates ubuntu 18.04

disable updates from command line in Ubuntu 16.04

Disable Software Updater Notification?

How to Enable/Disable Unattended Upgrades in Ubuntu 16.04

Terminate and disable/remove unattended upgrade before command returns

I have Ubuntu 18.04LTS.

I was used to locate as an indexed search tool. Combined with grep (and sometimes find) it is a swiss-army knife for file searching and inspecting.

I have yesterday noticed that something was eating up my little spare space available. Today I concluded ~/.local/share/baloo/index is the culprit.

The respective spaces taken are

/var/lib/mlocate/mlocate.db    47M
~/.local/share/baloo/index    7,5G

Is such a large difference normal? What additional information does baloo carry, to use such a large space? Can baloo be configured in a way that it uses a space similar to mlocate.db (even at the expense of some indexed information)?

PS 1: I didn't know about baloo until today.

PS 2: I have apt-get installed dolphin a couple of days ago, and I guess baloo came along.

PS 3: I have used dolphin since ancient times as well, in other systems, and I never noticed anything strange. I wouldn't know if in those other cases baloo was also installed but it lead to no issues, or if it was not installed at all.

I have a 1920x1080 screen connected directly to my Ubuntu 18.04 LTS server.

I am connecting to it via vino (server side) and vncviewer (client side, Win 10). In my client, I have a 1366x768 screen.

Is there any way to adapt the screen resolution for the remote session (i.e., without changing the resolution in the server), so I don't have to scroll in the vncviewer session to access the whole screen?

PS: In the vncviewer connection options there is a tab Screen. There are two check boxes Resize remote session on connect (with a resolution of 1366 x 768 specified) and Resize remote session to the local window They appear to provide for the intended effect, but they do not.

PS2: There is some info on how to do this with vncserver, e.g. below. But I have found none for vino.

https://superuser.com/questions/184338/how-to-change-screen-resolution-of-vnc-server-without-restarting-it

I have Java 11 and 8 in my Ubuntu 18.04, side by side. I mean to set Java 8 as the default.

What I get:

    $ sudo update-java-alternatives --set /usr/lib/jvm/java-1.8.0-openjdk-amd64
    update-alternatives: error: no alternatives for mozilla-javaplugin.so

    update-java-alternatives: plugin alternative does not exist: /usr/lib/jvm/java-8-openjdk-amd64/lib/IcedTeaPlugin.so

How can I get both plugins if they exist, work.

I am not sure if using (see this)

    sudo update-java-alternative —jre-headless -s java-1.8.0-openjdk-amd64

is ok, so I did not try it. Could it break anything? The Following are results after update-java-alternatives

    $ sudo update-alternatives --config java
    There are 2 choices for the alternative java (providing /usr/bin/java).

  Selection    Path                                            Priority   Status
------------------------------------------------------------
  0            /usr/lib/jvm/java-11-openjdk-amd64/bin/java      1101      auto mode
  1            /usr/lib/jvm/java-11-openjdk-amd64/bin/java      1101      manual mode
* 2            /usr/lib/jvm/java-8-openjdk-amd64/jre/bin/java   1081      manual mode

$ java -version
openjdk version "1.8.0_191"
OpenJDK Runtime Environment (build 1.8.0_191-8u191-b12-2ubuntu0.18.04.1-b12)
OpenJDK 64-Bit Server VM (build 25.191-b12, mixed mode)

This is the opposite change from

update-alternatives: error: no alternatives for mozilla-javaplugin.so

https://ubuntuforums.org/showthread.php?t=2402155

Related:

https://serverfault.com/questions/814064/set-jdk-8-as-the-default-java-on-debian-8

I am looking for an application that can compare two C++ sources and find the code-meaningful differences (to compare versions which may have been reformatted differently). At the very minimum, something which has the capability for ignoring changes in white spaces, tab spaces and newlines which do not affect the functionality of the source (note that whether a newline is considered whitespace is language-dependent, and C and C++ do so). And, ideally, something that can identify exactly all code-meaningful differences. I am under Ubuntu.

As per diff --help | grep ignore, I expected diff -bBwZ to do reasonably the job (I expected to get some false negatives, to be dealt with later). Nevertheless, it doesn't.

if I have the following files with snippets

test_diff1.txt

    else if (prop == "P1") { return 0; }

and test_diff2.txt

    else if (prop == "P1") {
        return 0;
    }

then

$ diff -bBwZ test_diff1.txt test_diff2.txt
1c1,3
<     else if (prop == "P1") { return 0; }
---
>     else if (prop == "P1") {
>         return 0;
>     }

instead of empty results.

Using a code formatter as a "filter" on both inputs may filter out these differences, but then the resulting output would have to be tied back to the original inputs for the final reporting of differences to keep actual text and line numbers. So the objective is attainable without a need for a compiler properly... I do not know if something is available, though.

Can the objective be attained with diff? Otherwise, is there an alternative (preferably, for command line)?