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28 votes
8 answers
40878 views
Terminal - copy from CLI without using mouse
While firing commands in CLI, **I want to copy the command I just fired** or anything I wrote in terminal and **paste it somewhere else** without using mouse. Like in following picture, I want to copy the update command (completely or partially) without using mouse and paste it somewhere. ![copy fro...
While firing commands in CLI, **I want to copy the command I just fired** or anything I wrote in terminal and **paste it somewhere else** without using mouse. Like in following picture, I want to copy the update command (completely or partially) without using mouse and paste it somewhere. copy from CLI without using mouse
prayagupadhyay (5047 rep)
Sep 22, 2013, 07:41 AM • Last activity: Aug 12, 2025, 02:47 AM
0 votes
1 answers
40 views
How do I recieve MMS messages in Spacebar with AT&T/ATT?
I have KDE's [Spacebar][1] installed on my Librem 5 but cannot figure out how to access/receive MMS messages. (edited image example) [![Screenshot of Spacebar with MMS Message][2]][2] I added my MMS settings but still get the message above: [![enter image description here][3]][3] Have any of you bee...
I have KDE's Spacebar installed on my Librem 5 but cannot figure out how to access/receive MMS messages. (edited image example) Screenshot of Spacebar with MMS Message I added my MMS settings but still get the message above: enter image description here Have any of you been able to receive MMS messages? I am attempting to receive cat photos. The screenshot was taken on Mobian. **Edit**: I am using AT&T (sometimes refered to as ATT) but would prefer a carrier-independent solution so that other may recieve help here as well
newunix (189 rep)
Aug 11, 2025, 04:58 AM • Last activity: Aug 12, 2025, 02:21 AM
4 votes
2 answers
3236 views
os-prober giving wrong UUID for Arch Linux
Up until yesterday, everything was working find and os-prober was successfully generating menu entries for the Arch Linux install. However today when I tried to boot into Arch, I got an error that the root file system could not be found at the UUID it was trying to use. After some tinkering I was ab...
Up until yesterday, everything was working find and os-prober was successfully generating menu entries for the Arch Linux install. However today when I tried to boot into Arch, I got an error that the root file system could not be found at the UUID it was trying to use. After some tinkering I was able to get Arch to boot by manually changing the root to the actual partition "/dev/sda7" as opposed to using UUID. I was wondering what might cause os-prober to be generating this invalid configuration just for the Arch Linux install. It does fine still for the openSUSE and Windows 7 installs. One other thing to note is that it has added "rw quiet" to the end of the boot line for Arch Linux. That is not something it previously did, and I am wondering if whatever changed that has to do with why the UUID is incorrect. Below I will post the menu entry for Arch Linux. As you can see os-prober has the --set-root= 'some UUID' part with the correct UUID, but later on when booting linux it has -root=UUID='some other incorrect UUID'. Just to clarify, I have Ubuntu, Arch Linux, openSUSE, and Windows 7 on this machine, but I am using Ubuntu as the main OS and allowing it to manage GRUB and its configurations. All of the operating systems are at their most up-to-date versions. menuentry 'Arch (on /dev/sda7)' --class gnu-linux --class gnu --class os $menuentry_id_option 'osprober-gnulinux-simple-b9522736-878c-49e3-b30d-ad65589aa1d9' { insmod part_msdos insmod ext2 set root='hd0,msdos7' if [ x$feature_platform_search_hint = xy ]; then search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos7 --hint-efi=hd0,msdos7 --hint-baremetal=ahci0,msdos7 b9522736-878c-49e3-b30d-ad65589aa1d9 else search --no-floppy --fs-uuid --set=root b9522736-878c-49e3-b30d-ad65589aa1d9 fi linux /boot/vmlinuz-linux root=UUID=ad4103fa-d940-47ca-8506-301d8071d467 rw quiet initrd /boot/initramfs-linux.img } As you can see the first two UUIDs are different from the last one. The first two are correct and the last one is wrong. If I replace the last UUID with '/dev/sda7', Then it boots without problem. I have manually edited the grub.cfg to do this, but I would like os-prober to get back to working automatically. Thanks.
user256518
May 10, 2014, 03:42 PM • Last activity: Aug 12, 2025, 02:07 AM
2 votes
1 answers
3142 views
Where are kernel and initramfs files for systemd-boot?
I'm trying to do a fresh install and use `systemd-boot` as the bootloader for my ESP, but in the [install instructions](https://wiki.archlinux.org/index.php/systemd-boot#EFI_boot) on step 4 it says: > Copy your kernel and initramfs onto that ESP. But where are `vmlinuz-linux` and `initramfs-linux.im...
I'm trying to do a fresh install and use systemd-boot as the bootloader for my ESP, but in the [install instructions](https://wiki.archlinux.org/index.php/systemd-boot#EFI_boot) on step 4 it says: > Copy your kernel and initramfs onto that ESP. But where are vmlinuz-linux and initramfs-linux.img located? I can't find them for the life of me. Do I need to install bootctl before those files are available? Nothing exists in /boot in either my Arch Linux install disk or the partitions that I'm working with
starscream_disco_party (165 rep)
Aug 4, 2016, 05:35 PM • Last activity: Aug 12, 2025, 02:01 AM
5 votes
1 answers
6268 views
Two *different* mount points having the *same* absolute path (bind-mount problem)
Scenario -------- - a NFS share is mounted on `/mnt/temp/dir` (and other shares are mounted in subdirectories), - I `umount` everything there but supposedly, it doesn't work well (maybe I start with `umount /mnt/temp/dir` instead of umounting "nested" shares like `/mnt/temp/dir/subdir*` first), - I...
Scenario -------- - a NFS share is mounted on /mnt/temp/dir (and other shares are mounted in subdirectories), - I umount everything there but supposedly, it doesn't work well (maybe I start with umount /mnt/temp/dir instead of umounting "nested" shares like /mnt/temp/dir/subdir* first), - I do mount -o bind /data/temp /mnt/temp, - I do mount /mnt/temp/dir, - I do mount /mnt/temp/dir/subdir1... and it works well. Note: /mnt/temp is initially hosted on the root (/) filesystem /dev/sda6, and /data is another filesystem from /dev/sda8. Problem ------- I cannot delete the /mnt/temp/dir directory on the root filesystem: # mount -o bind / /test/root # rmdir /test/root/mnt/temp/dir rmdir: failed to remove `dir': Device or resource busy Some explanation ----------------- /mnt/temp/dir is mounted ***twice***, probably once on the root fs, and once on the /data fs. Here is cat /proc/mounts: nfsserver:/some/share/ /mnt/temp/dir nfs rw,relatime(...) 0 0 nfsserver:/some/share/ /mnt/temp/dir nfs rw,relatime,(...) 0 0 More interesting, here is cat /proc/1/mountinfo: 29 20 0:18 / /mnt/temp/dir rw,relatime - nfs nfsserver:/some/share/ rw,(...) 33 31 0:18 / /mnt/temp/dir rw,relatime - nfs nfsserver:/some/share/ rw,(...) See, the two numbers at the beginning are *different*. Kernel doc says for these two fields: (1) mount ID: unique identifier of the mount (may be reused after umount) (2) parent ID: ID of parent (or of self for the top of the mount tree) They also have different parents 20 and 31 (root fs and /data fs), see: 20 1 8:6 / / rw,relatime - ext4 /dev/sda6 rw,(...) 31 20 8:8 /temp /mnt/temp rw,relatime - ext4 /dev/sda8 rw,(...) If I try to umount /mnt/temp/dir, I get 2 error messages: umount.nfs: /mnt/temp/dir: device is busy umount.nfs: /mnt/temp/dir: device is busy Question ======== **How can I umount the "bad" one (mount ID 29)?** Even the umount(2) system call takes a path for argument, and not a "mount ID".
Totor (21040 rep)
Feb 27, 2015, 06:24 PM • Last activity: Aug 12, 2025, 01:06 AM
0 votes
1 answers
57 views
Debian Trixie: problems with Lxc unprivileged Containers
On Debian 12 bullseye all works fine. This is the situation on Debian Trixie (released stable some days ago) lxc-ls: ../src/lxc/utils.c: switch_to_ns: 900 Operation not permitted - Failed to set process 3227 to "net" of 3 lxc-ls: ../src/lxc/utils.c: switch_to_ns: 900 Operation not permitted - Failed...
On Debian 12 bullseye all works fine. This is the situation on Debian Trixie (released stable some days ago) lxc-ls: ../src/lxc/utils.c: switch_to_ns: 900 Operation not permitted - Failed to set process 3227 to "net" of 3 lxc-ls: ../src/lxc/utils.c: switch_to_ns: 900 Operation not permitted - Failed to set process 3312 to "net" of 3 lxc-ls: ../src/lxc/utils.c: switch_to_ns: 900 Operation not permitted - Failed to set process 3312 to "net" of 3 lxc-ls: ../src/lxc/utils.c: switch_to_ns: 900 Operation not permitted - Failed to set process 3312 to "net" of 3 lxc-ls: ../src/lxc/utils.c: switch_to_ns: 900 Operation not permitted - Failed to set process 3382 to "net" of 3 lxc-ls: ../src/lxc/utils.c: switch_to_ns: 900 Operation not permitted - Failed to set process 3382 to "net" of 3 lxc-ls: ../src/lxc/utils.c: switch_to_ns: 900 Operation not permitted - Failed to set process 3382 to "net" of 3 lxc-ls: ../src/lxc/utils.c: switch_to_ns: 900 Operation not permitted - Failed to set process 3436 to "net" of 3 lxc-ls: ../src/lxc/utils.c: switch_to_ns: 900 Operation not permitted - Failed to set process 3436 to "net" of 3 lxc-ls: ../src/lxc/utils.c: switch_to_ns: 900 Operation not permitted - Failed to set process 3436 to "net" of 3 NAME STATE AUTOSTART GROUPS IPV4 IPV6 UNPRIVILEGED cacti1 RUNNING 0 - - - true certauth1 RUNNING 0 - - - true dns1 RUNNING 0 - - - true Seems working, but.. lxc-attach dns1 lxc-attach: dns1: ../src/lxc/cgroups/cgfsng.c: enter_scope: 1335 Failed opening dbus connection lxc-attach: dns1: ../src/lxc/cgroups/cgfsng.c: cgroup_attach_move_into_leaf: 2859 Failed entering scope 'lxc-dns1-0.scope' lxc-attach: dns1: ../src/lxc/cgroups/cgfsng.c: cgroup_attach_move_into_leaf: 2897 Permission denied - Failed to move process into target cgroup via fd 7 and 8 lxc-attach: dns1: ../src/lxc/conf.c: userns_exec_minimal: 4685 Permission denied - Running parent function failed lxcunpriv@nas:~$ lxc-attach: dns1: ../src/lxc/attach.c: do_attach: 1238 No data available - Failed to receive lsm label fd lxc-attach: dns1: ../src/lxc/attach.c: do_attach: 1376 Failed to attach to container The containers are unprivileged I have tried with systemd.unified_cgroup_hierarchy=false and not but same result. After some seconds all containers fails NAME STATE AUTOSTART GROUPS IPV4 IPV6 UNPRIVILEGED cacti1 STOPPED 0 - - - true certauth1 STOPPED 0 - - - true dns1 STOPPED 0 - - - true Trying with debug lxc-start -n dns1 -F -l DEBUG -o /tmp/lxc-nomecontainer.log lxc-start: dns1: ../src/lxc/cgroups/cgfsng.c: unpriv_systemd_create_scope: 1526 Failed opening dbus connection Failed to mount cgroup at /sys/fs/cgroup/systemd: Operation not permitted [!!!!!!] Failed to mount API filesystems. Exiting PID 1... lxc-checkconfig report all fine lxc-checkconfig LXC version 6.0.4 Kernel configuration not found at /proc/config.gz; searching... Kernel configuration found at /boot/config-6.12.38+deb13-amd64 --- Namespaces --- Namespaces: enabled Utsname namespace: enabled Ipc namespace: enabled Pid namespace: enabled User namespace: enabled Network namespace: enabled Namespace limits: cgroup: 127838 ipc: 127838 mnt: 127838 net: 127838 pid: 127838 time: 127838 user: 127838 uts: 127838 --- Control groups --- Cgroups: enabled Cgroup namespace: enabled Cgroup v1 mount points: Cgroup v2 mount points: - /sys/fs/cgroup Cgroup device: enabled Cgroup sched: enabled Cgroup cpu account: enabled Cgroup memory controller: enabled Cgroup cpuset: enabled --- Misc --- Veth pair device: enabled, loaded Macvlan: enabled, not loaded Vlan: enabled, loaded Bridges: enabled, loaded Advanced netfilter: enabled, loaded CONFIG_IP_NF_TARGET_MASQUERADE: enabled, not loaded CONFIG_IP6_NF_TARGET_MASQUERADE: enabled, not loaded CONFIG_NETFILTER_XT_TARGET_CHECKSUM: enabled, not loaded CONFIG_NETFILTER_XT_MATCH_COMMENT: enabled, not loaded FUSE (for use with lxcfs): enabled, not loaded --- Checkpoint/Restore --- checkpoint restore: enabled CONFIG_FHANDLE: enabled CONFIG_EVENTFD: enabled CONFIG_EPOLL: enabled CONFIG_UNIX_DIAG: enabled CONFIG_INET_DIAG: enabled CONFIG_PACKET_DIAG: enabled CONFIG_NETLINK_DIAG: enabled File capabilities: enabled Note: Before booting a new kernel, you can check its configuration with: CONFIG=/path/to/config /usr/bin/lxc-checkconfig Any idea? EDIT1: This script which fix something on some lxc versions fail completely #!/bin/bash # this is for the password in cache printf '\n\033[42mCreating cgroup hierarchy\033[m\n\n' && for d in /sys/fs/cgroup/*; do f=$(basename $d) echo "looking at $f" if [ "$f" = "cpuset" ]; then echo 1 | sudo tee -a $d/cgroup.clone_children; elif [ "$f" = "memory" ]; then echo 1 | sudo tee -a $d/memory.use_hierarchy; fi sudo mkdir -p $d/$USER sudo chown -R $USER $d/$USER # add current process to cgroup #echo $PPID > $d/$USER/tasks done mkdir: cannot create directory ‘/sys/fs/cgroup/cgroup.controllers’: not a directory chown: impossible to access on '/sys/fs/cgroup/cgroup.controllers/lxcunpriv': not a directory
elbarna (13738 rep)
Aug 10, 2025, 02:06 AM • Last activity: Aug 12, 2025, 12:23 AM
9 votes
3 answers
6892 views
Is there a way to empty the trash/wastebasket from the command line?
This would be great especially considering the latest version of Ubuntu is very slow when displaying directories on my PC...
This would be great especially considering the latest version of Ubuntu is very slow when displaying directories on my PC...
ixtmixilix (13530 rep)
Oct 10, 2010, 10:22 PM • Last activity: Aug 12, 2025, 12:22 AM
0 votes
1 answers
3856 views
How to disable ModemManager in linux mint?
When I setting up qmk_firmware, it throws ``` ⚠ Detected ModemManager. Please disable it if you are using a Pro-Micro. Ψ Problems detected, please fix these problems before proceeding. ``` I've tried both `systemctl disable ModemManager.service` and `sudo mv /usr/share/dbus-1/system-services/org.fre...
When I setting up qmk_firmware, it throws
⚠ Detected ModemManager. Please disable it if you are using a Pro-Micro.
Ψ Problems detected, please fix these problems before proceeding.
I've tried both systemctl disable ModemManager.service and sudo mv /usr/share/dbus-1/system-services/org.freedesktop.ModemManager1.service /usr/share/dbus-1/system-services/org.freedesktop.ModemManager1.service.disabled, but neither works. Also tried to logout and in. Didn't see any logs from this though.
$ systemctl list-dependencies multi-user.target | grep Modem
Mengo (103 rep)
Sep 13, 2020, 11:30 PM • Last activity: Aug 12, 2025, 12:00 AM
80 votes
4 answers
12779 views
I accidentally typed my password into the login field, is it still secure?
I was looking down at my keyboard and typed my password in because I thought I had already typed my login name. I pressed Enter , then when it asked for the password I pressed Ctrl + c . Should I take some precautionary measure to make sure the password isn't stored in plain text somewhere or should...
I was looking down at my keyboard and typed my password in because I thought I had already typed my login name. I pressed Enter, then when it asked for the password I pressed Ctrl+c. Should I take some precautionary measure to make sure the password isn't stored in plain text somewhere or should I change the password? Also this was on a tty on ubuntu server 16.04 LTS.
hermancain (1309 rep)
Apr 24, 2016, 09:38 PM • Last activity: Aug 11, 2025, 11:37 PM
3 votes
1 answers
2064 views
Value of /proc/sys/kernel/hostname
I've set computer hostname in `/etc/hostname` a while ago (also there are record in `/etc/hosts`). Everything worked fine, but recently I've noticed that value of `hostname` (and `/proc/sys/kernel/hostname`) changed (to hostname of neighbour computer), although I haven't touched anything related. Va...
I've set computer hostname in /etc/hostname a while ago (also there are record in /etc/hosts). Everything worked fine, but recently I've noticed that value of hostname (and /proc/sys/kernel/hostname) changed (to hostname of neighbour computer), although I haven't touched anything related. Value of /etc/hostname remains correct. Which mechanism may cause such change? There are similar problem description , but it doesn't contains any solution.
valodzka (405 rep)
Nov 22, 2013, 01:33 PM • Last activity: Aug 11, 2025, 11:03 PM
3 votes
1 answers
2499 views
Debian apt issue (not found and deb12u1)
I wanted to install texmaker the other day but I ran into an issue : it downloaded 500mb but it told me it could not find a few dependencies, for instance `Err : 4 http://deb.debian.org/debian/pool/main/t/texlive-bin/texlive-binaries_2022.20220321.62855-5.1_amd64.deb 404 Not Found [IP : .... 80]` I...
I wanted to install texmaker the other day but I ran into an issue : it downloaded 500mb but it told me it could not find a few dependencies, for instance Err : 4 http://deb.debian.org/debian/pool/main/t/texlive-bin/texlive-binaries_2022.20220321.62855-5.1_amd64.deb 404 Not Found [IP : .... 80] I looked it up on the repo, it was there with a different name : http://deb.debian.org/debian/pool/main/t/texlive-bin/texlive-binaries_2022.20220321.62855-5.1+deb12u1_amd64.deb The error suggested that i run the command with --fix-missing and run apt update before, but it didnt work. So i tried to download the file and install it with sudo apt install ./texlive-binaries...+deb12u1_amd64.deb. Then running sudo apt install texmaker still did not found the package as it recognized the version is 5.1+deb12u1_amd64 and not 5.1. I looked it up on google, did not find much, and moved on Overleaf. But today, i ran apt update && apt upgrade, and after i reboot i come to a tty. I am surprised. I found out i can't start gnome with startx or sudo systemctl enable gdm3. It turns out apt updated gnome-shell-common to a deb12u1_amd64 version, and it broke the DE. Now apt lists all the gnome packets as installed automatically and not needed anymore, aswell as bolt, gir1, ibus, ... I am confused, when i run apt install gdm3 it tells me gnome-shell depends on gnome-shell-common = 43.4-1 but 43.6-1~deb12u1 will be installed. Impossible to fix the problem. I looked up /etc/apt/sources.list but everything seems fine :
deb http://deb.debian.org/debian  bookworm flags
deb-src http://deb.debian.org/debian  bookworm flags

deb http://security.debian.org/debian-security  bookworm-security flags
deb-src http://security.debian.org/debian-security  bookworm-security flags

deb http://deb.debian.org/debian  bookworm-updates flags
deb-src http://deb.debian.org/debian  bookworm-updates flags
where flags is main non-free-firmware non-free contrib. Also in source.list.d I have vscodium.list which contains deb [singed-by = /usr/share...gpg ] https://download.vscodium.con/debs vscodium main apt policy gnome gnome-shell returns
gnome:
  installed : none
  candidate : 1:43+1
  version table :
    1:43+1 500
    500 http://deb.debian.org/debian  bookworm/main amd64 Packages
gnome-shell:
  installed : none
  candidate :43.4-1
  version table :
    43.4-1 500
    500 http://deb.debian.org/debian  bookworm/main amd64 Packages
    100 /var/lib/dpkg/status
Here is the content of apt update :
Reached :1 http://deb.debian.org/debian  bookworm InRelease
Reached :2 http://security.debian.org/debian-security  bookworm-security InRelease
Reached :3 http://deb.debian.org/debian  bookworm-updates InRelease
Reached :4 http://download.vscodium.com/debs  vscodium InRelease
Reading list ... done
Constructing dependency tree ... done
Reading information status ... done
1 packet can be updated. Run apt list --upgradable to see it
Now I have a new update which is nvidia-installer-cleanup and apt policy nvidia-installer=cleanup is :
nvidia-installer-cleanup:
  installed : 20220217+2
  candidate : 20220217+3~deb12u1
  version table :
    20220217+3~deb12u1 500
      500 http://deb.debian.org/debian  bookworm/contrib amd64 Packages
    20220217+2 100 
      100 /var/lib/dpkg/status
But i think i found the issue. I have a Brother HL-2135W printer that used to work on Debian 11. However, this time it did not work out of the box so when i tried to install it with the script found on Brother's support website, it was a 32 bit script : https://www.brother.fr/services-et-supports/hl-2135w/downloads The script messed up libc6-i386. I had to run dpkg -add-architecture i386 which messed up apt. dpkg -l | grep i386 outputs
cupswrapperhl2130:i386
hl2130lpr:i386
so I uninstalled those two packages and run dpkg --remove-architecture i386. But I still can't install gnome. There is a deeper issue with apt probably. I run Debian 12 bookworm on an Dell Inspiron 5415 with Ryzen 5 5500U. Thanks for your help.
themathsdude (33 rep)
Sep 10, 2023, 02:21 PM • Last activity: Aug 11, 2025, 10:14 PM
0 votes
1 answers
3928 views
read_passphrase being called on SSH key even though SSH key is not protected by password
I have a staging server and a production server, and I run identical Bitbucket Pipelines, where I send some commands over SSH. Unfortunately, my pipeline for the production always fails with: ``` Host key verification failed. ``` I've tried _everything_, folder permissions, recreating the keys, noth...
I have a staging server and a production server, and I run identical Bitbucket Pipelines, where I send some commands over SSH. Unfortunately, my pipeline for the production always fails with:
Host key verification failed.
I've tried _everything_, folder permissions, recreating the keys, nothing works. Finally with adding -v to my ssh call, I think I'm a step closer, but still lost. On my staging server, I see something like this:
debug1: Host '$STAGING_SERVER' is known and matches the RSA host key.	
debug1: Found key in /root/.ssh/known_hosts:4	
debug1: ssh_rsa_verify: signature correct
and the rest of the build follows flawlessly. On my production server, however, I see the following:
debug1: Host '$PRODUCTION_SERVER' is known and matches the RSA host key.
debug1: Found key in /root/.ssh/known_hosts:5
debug1: read_passphrase: can't open /dev/tty: No such device or address
debug1: permanently_drop_suid: 0
ssh_askpass: exec(/usr/bin/ssh-askpass): No such file or directory
Host key verification failed.
So it would look like the key _is_ found on my production server, but for some reason on the production server read_passphrase is being called. I've just created a new id_rsa and id_rsa.pub key, with _no_ password, so why the heck is my production server trying to call read_passphrase? My ssh_config and sshd_config on both servers are identical - checked via diff. Another way of looking at it is that ssh_rsa_verify is called immediately on the staging server, while on the production server read_passphrase is called. Any help here would be greatly appreciated, this is driving me crazy!
fullStackChris (101 rep)
Dec 13, 2021, 02:18 PM • Last activity: Aug 11, 2025, 10:03 PM
9 votes
1 answers
2736 views
gdm greeter configuration: Exclude all *except* for one specific user
I have Googled this one and tried so many combinations, with no success. I need the GDM login greeter to display one and only one username. In effect, what I need is something like this in **/etc/gdm/custom.conf**: [greeter] ExcludeAll=true Include=guest This does not work, however, because ExcludeA...
I have Googled this one and tried so many combinations, with no success. I need the GDM login greeter to display one and only one username. In effect, what I need is something like this in **/etc/gdm/custom.conf**: [greeter] ExcludeAll=true Include=guest This does not work, however, because ExcludeAll is not a valid option. IncludeAll=false does nothing either. I've tried every combination that I can think of. Despite being discouraged, I modified **/etc/gdm/gdm.schemas**, trying a variety of combinations similar to the above. No go. I am aware of: gconftool-2 --config-source xml:readwrite:/etc/gconf/gconf.xml.defaults --direct --type bool --set /apps/gdm/simple-greeter/disable_user_list true but this is not an applicable solution, as it removes the user list completely. I need one specific username to appear. The only practical solution I can find is to, upon user login, run a script which will append that username to the "Exclude" list in **/etc/gdm/custom.conf**. This is hacky, and not preferable. This is for a public-use machine. People can log in with their LDAP accounts if they have them, or they can select "Guest" from the login screen. The people who log in with their LDAP accounts should NOT have their names visible on the login screen, but the "Guest" option must remain. Using gnome 2.28.
CptSupermrkt (1512 rep)
Apr 15, 2014, 08:01 PM • Last activity: Aug 11, 2025, 09:02 PM
1 votes
1 answers
16817 views
JAVA_HOME should point to a JDK not a JRE
If anyone can help me with this, it would mean a lot as I've seen similarly answered questions for windows but not many or Linux. I am running I am running Linux mint 20.2 (Uma). I have a problem where trying to run my maven project, I get the error ``` The JAVA_HOME environment variable is not defi...
If anyone can help me with this, it would mean a lot as I've seen similarly answered questions for windows but not many or Linux. I am running I am running Linux mint 20.2 (Uma). I have a problem where trying to run my maven project, I get the error
The JAVA_HOME environment variable is not defined correctly
This environment variable is needed to run this program
NB: JAVA_HOME should point to a JDK not a JRE
I have since fully uninstalled java and maven and set up JDK17 and the JAVA_HOME
$ echo $JAVA_HOME
/usr/lib/jvm/jdk-17.0.2
Along with setting the profile
$ grep JAVA_HOME /etc/profile

JAVA_HOME=/usr/lib/jvm/jdk-17.0.2
JRE_HOME=$JAVA_HOME/jre
PATH=$PATH:JAVA_HOME/bin:$JRE_HOME/bin
export JAVA_HOME
And .bashrc
$ grep JAVA_HOME ~/.bashrc

JAVA_HOME=/usr/lib/jvm/jdk-17.0.2
JRE_HOME=$JAVA_HOME/jre
PATH=$PATH:JAVA_HOME/bin:$JRE_HOME/bin
export JAVA_HOME
I also found a
.sh
file in the
/etc/profile.d/
that was redirecting JAVA_HOME to the old JDK and have since deleted it. But even after all of this the problem pressies, I don't know if something is still redirecting JAVA_HOME to the old JDK or I didn't set it up correctly, I also don't know where to look if something is redirecting it or if I have an alias for
since I'm not adept to Linux fully and I haven't used to this system in a while to backtrack my changes. If anyone has any input on how to solve this problem, it would be greatly appreciated. Thank you all in advance.
SaltySwan (11 rep)
Feb 19, 2022, 04:39 PM • Last activity: Aug 11, 2025, 08:03 PM
27 votes
4 answers
11819 views
Practical limit on the number of btrfs snapshots?
I am considering using btrfs on my data drive so that I can use [snapper](http://snapper.io/), or something like snapper, to take time based snapshots. I believe this will let me browse old versions of my data. This would be in addition to my current off site backup since a drive failure would wipe...
I am considering using btrfs on my data drive so that I can use [snapper](http://snapper.io/) , or something like snapper, to take time based snapshots. I believe this will let me browse old versions of my data. This would be in addition to my current off site backup since a drive failure would wipe out the data and the snapshots. From my understanding btrfs snapshots do not take up much space (meta data and the blocks that have changed, plus maybe some overhead), so space doesn't seem to be a constraint. If I have a million snapshots (e.g., a snapshot every minute for two years) would that cause havoc, assuming I have enough disk space for the data, the changed data, and the meta data? If there is a practical limit on the number of snapshots, does it depend on the number of files and/or size of files?
StrongBad (5491 rep)
Jul 2, 2014, 12:00 PM • Last activity: Aug 11, 2025, 07:29 PM
4 votes
4 answers
476 views
Creating n folders with equal number of files from a large folder with all files
I have a large folder of data files, which I want to copy into subfolders to make a specified number of batches. Right now I count how many files there are and use that to make ranges, like so: ``` cd /dump batches=4 files=$(cat /data/samples.txt | wc -l) echo "$files $batches" for ((i=0; i<=batches...
I have a large folder of data files, which I want to copy into subfolders to make a specified number of batches. Right now I count how many files there are and use that to make ranges, like so:
cd /dump
batches=4
files=$(cat /data/samples.txt | wc -l)

echo "$files $batches"
for ((i=0; i<=batches; i++))
do
    mkdir -p merged_batches/batch$i
    rm -f merged_batches/batch$i/*

    ls merged/*.sorted.labeled.bam* |
      head -n $(( $((files/batches)) * $((i+1)) * 2 )) |
      tail -n $((2 * files/batches)) |
      xargs -I {} cp {} merged_batches/batch$i

done
Is there a more convenient way to do this?
rubberduck (53 rep)
Aug 7, 2025, 03:49 PM • Last activity: Aug 11, 2025, 07:21 PM
1 votes
1 answers
2866 views
Reverse Proxy with Apache presenting blank page
I've got one Raspberry Pi 2 Model B running Deluge and Deluge Web UI 24/7. I set up a No-IP free host so I can access the Rasperry Pi to download some data I've stored in a 3TB disk. I am using Apache2 as the webserver but I am looking forward to change to a Go application I am creating myself. The...
I've got one Raspberry Pi 2 Model B running Deluge and Deluge Web UI 24/7. I set up a No-IP free host so I can access the Rasperry Pi to download some data I've stored in a 3TB disk. I am using Apache2 as the webserver but I am looking forward to change to a Go application I am creating myself. The WebUI Deluge listening port is **9090**. I wanted to access Deluge WebUI without having to type :9090 in the end of the hostname (via /del would be ideal). I read multiple questions on SO where the Reverse Proxies were mentioned. I quickly checked the official documentation. The changes I've made to my configuration files are the following: */etc/apache2/sites-enabled/000-default.conf* ProxyPass /del http://hostname:9090/ ProxyPassReverse /del http://hostname:9090/ I also tried **rewrite** in 000-default (but in different times) RewriteEngine on RewriteCond %{REQUEST_URI} /del [NC] RewriteRule ^(.*)$ http://hostname:9090 [P] Restarted Apache and the result is a blank page whenever I visit http://hostname/del **(via browser)**
fabiofcferreira (121 rep)
Sep 2, 2017, 06:59 PM • Last activity: Aug 11, 2025, 07:04 PM
0 votes
0 answers
31 views
Sendmail wont work for my ubuntu terminal server (Ubuntu 24.04.2)
I'm currently attempting (and failing) to set up an SMTP mail server on my Ubuntu server so I can recieve emails from the contact page of my php based website. I was planning to send these emails using phps built in mail() function. However, no matter what I try the email either never sends with no...
I'm currently attempting (and failing) to set up an SMTP mail server on my Ubuntu server so I can recieve emails from the contact page of my php based website. I was planning to send these emails using phps built in mail() function. However, no matter what I try the email either never sends with no errors (in the case of using sendmail) or causes a client-side timeout (in the case of using postfix). If anyone can help me it'd be greatly appreciated! I'm rather new to using SMTP related stuff so I don't really know what log files to attach so please ask me for them if needed. Thanks. Edit: port 25 is forwarded
Hoax (1 rep)
Aug 11, 2025, 06:16 PM • Last activity: Aug 11, 2025, 06:32 PM
15 votes
2 answers
7924 views
How to disable suspend on close laptop lid on NixOS?
I'm using [NixOS](http://nixos.org), so the approach described in “https://unix.stackexchange.com/q/52643/11397”, editing `/etc/systemd/logind.conf`, won't work, as it is just a symlink to `/etc/static/systemd/logind.conf`, which itself is a symlink to a file in `/nix/store`. AFAIK, you shouldn't ed...
I'm using [NixOS](http://nixos.org) , so the approach described in “https://unix.stackexchange.com/q/52643/11397” , editing /etc/systemd/logind.conf, won't work, as it is just a symlink to /etc/static/systemd/logind.conf, which itself is a symlink to a file in /nix/store. AFAIK, you shouldn't edit the *Nix store* directly. But the file in /nix/store doesn't have write permissions anyway. How do I disable laptop auto-suspension in a NixOS idiomatic way?
Mirzhan Irkegulov (8818 rep)
Jan 25, 2016, 06:43 PM • Last activity: Aug 11, 2025, 06:11 PM
1 votes
1 answers
1970 views
How to show all current ssh connected users on Linux?
Using GCP VM Instance, I'm connected via ssh, not serial port. When I type `w` or `who` or `finger` I get the following output: ``` $ w 08:46:18 up 41 min, 0 users, load average: 0.10, 0.07, 0.01 USER TTY FROM LOGIN@ IDLE JCPU PCPU WHAT $ who $ finger No one logged on. ``` I'm expecting to see my cu...
Using GCP VM Instance, I'm connected via ssh, not serial port. When I type w or who or finger I get the following output:
$ w
08:46:18 up 41 min,  0 users,  load average: 0.10, 0.07, 0.01
USER     TTY      FROM             LOGIN@   IDLE   JCPU   PCPU WHAT

$ who                                                                                                                         

$ finger                                                                                                                      No one logged on.
I'm expecting to see my current connected user, but this is not the case. I tried to connect as another user along mine and it showed, but not my primary user, either when he or the other runs the command.
> pstree -alus "$$" 
systemd
  └─sshd
      └─sshd
          └─sshd,Dédé
              └─bash
                  └─bash
                      └─code-e170252f76 command-shell --cli-data-dir /home/Dédé/.vscode-server/cli --parent-process-id 234934 --on-port
                          └─sh /home/Dédé/.vscode-server/cli/servers/Stable-e170252f762678dec6ca2cc69aba1570769a5d39/server/bin/code-server --connection-token=remotessh --accept-server-license-terms --start-server --enable-remote-auto-shutdown --socket-path=/tmp/code-bd3d6d38-59de-47a1-8df7-54881cb666dd
                              └─node /home/Dédé/.vscode-server/cli/servers/Stable-e170252f762678dec6ca2cc69aba1570769a5d39/server/out/server-main.js --connection-token=remotessh --accept-server-license-terms --start-server --enable-remote-auto-shutdown --socket-path=/tmp/code-bd3d6d38-59de-47a1-8df7-54881cb666dd
                                  └─node /home/Dédé/.vscode-server/cli/servers/Stable-e170252f762678dec6ca2cc69aba1570769a5d39/server/out/bootstrap-fork --type=ptyHost --logsPath /home/Dédé/.vscode-server/data/logs/20240504T173238
                                      └─zsh -i
                                          └─pstree -alus 271031
D&#233;d&#233; (11 rep)
May 4, 2024, 10:57 AM • Last activity: Aug 11, 2025, 06:08 PM
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