| Merge text and Json files Posted: 10 Nov 2021 09:48 AM PST I have a text file that looks like this AWSDynamoDB/01629227303395-c3801363/_started AWSDynamoDB/01629227303395-c3801363/data/57sxfwx54y63xo46yhna6qgf3e.json.gz
Have a JSON file that looks like this. { "TagSet": [test:tag] } { "TagSet": [foo:bar] }
I'd like to merge these files in a way that the output will look like this. AWSDynamoDB/01629227303395-c3801363/_started { "TagSet": [test:tag] } AWSDynamoDB/01629227303395-c3801363/data/57sxfwx54y63xo46yhna6qgf3e.json.gz { "TagSet": [test:tag] }
or this. AWSDynamoDB/01629227303395-c3801363/_started "TagSet": [test:tag] AWSDynamoDB/01629227303395-c3801363/data/57sxfwx54y63xo46yhna6qgf3e.json.gz "TagSet": [foo:bar]
I tried using paste input.txt output.json | pr -t -e24
But its not giving me the output that I am looking. How can I achieve this?  |
| WiFi interface configured as AP is down after system restart Posted: 10 Nov 2021 09:48 AM PST I'm trying to setup my WiFi interface in AP mode using hostapd. However, after system restart startup hangs for about 2min on: A start job is running for Wait for Network to be Configured
It seems that WiFi interface is not getting UP and that is why systemd-networkd-wait-online.service hangs. It does not if I set WiFi interface as ignored in systemd-networkd-wait-online.service, but this does not solve the general problem. After system startup I see this output after I execute ip addr command: 3: wlxc04a0010118a: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc mq state DOWN group default qlen 1000 link/ether c0:4a:00:10:11:8a brd ff:ff:ff:ff:ff:ff
As I expected interface is DOWN. sudo ip link set wlxc04a0010118a up does not change interface status. To bring it UP and fix my issue I have to execute systemctl restart hostapd.service
Then ip addr command returns: 3: wlxc04a0010118a: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000 link/ether c0:4a:00:10:11:8a brd ff:ff:ff:ff:ff:ff inet 172.24.1.1/24 brd 172.24.1.255 scope global wlxc04a0010118a valid_lft forever preferred_lft forever
I would like to fix that and have WiFi AP configured after system startup without this manual step as other services rely on this interface and eventualy have to be also started manualy when interface is up. I tried many things but still cannot solve this. I would appreciate your help. My /etc/hostapd/hostapd.conf: interface=wlxc04a0010118a # Use the nl80211 driver with the brcmfmac driver driver=nl80211 ssid=Wifinetwork hw_mode=g channel=6 ieee80211n=1 wmm_enabled=1 # Enable 40MHz channels with 20ns guard interval #ht_capab=[HT40][SHORT-GI-20][DSSS_CCK-40] macaddr_acl=0 auth_algs=1 ignore_broadcast_ssid=0 wpa=2 wpa_key_mgmt=WPA-PSK wpa_passphrase=Wifipassword rsn_pairwise=CCMP
Interface configuration: /lib/systemd/network/80-wifi-ap.network: [Match] Name=wlxc04a0010118a [Network] Address=172.24.1.1/24 DHCPServer=no IPForward=ipv4 IPMasquerade=no
/etc/dnsmasq.conf:
interface=wlxc04a0010118a # Use interface wlan0 listen-address=172.24.1.1 # Explicitly specify the address to listen on bind-dynamic # Bind to the interface to make sure we aren't sending things elsewhere server=8.8.8.8 # Forward DNS requests to Google DNS domain-needed # Don't forward short names bogus-priv # Never forward addresses in the non-routed address spaces. dhcp-option=6,172.24.1.1,192.168.1.1 domain=domain1 dhcp-range=172.24.1.50,172.24.1.150,12h
Result of systemctl status hostapd.service before hostapd restart: ● hostapd.service - Hostapd IEEE 802.11 Access Point Loaded: loaded (/etc/systemd/system/hostapd.service; enabled; vendor preset: enabled) Active: active (running) since Wed 2021-11-10 16:42:02 UTC; 4min 48s ago Process: 780 ExecStartPre=/sbin/ip link set wlxc04a0010118a up (code=exited, status=0/SUCCESS) Process: 794 ExecStart=/usr/sbin/hostapd -B /etc/hostapd/hostapd.conf -P /var/run/hostapd.pid (code=exited, sta> Main PID: 966 (hostapd) Tasks: 1 (limit: 4596) Memory: 2.4M CGroup: /system.slice/hostapd.service └─966 /usr/sbin/hostapd -B /etc/hostapd/hostapd.conf -P /var/run/hostapd.pid Nov 10 16:41:58 domain1 systemd[1]: Starting Hostapd IEEE 802.11 Access Point... Nov 10 16:41:58 domain1 hostapd[794]: Configuration file: /etc/hostapd/hostapd.conf Nov 10 16:42:00 domain1 hostapd[794]: Using interface wlxc04a0010118a with hwaddr c0:4a:00:10:11:8a and ssid "> Nov 10 16:42:02 domain1 hostapd[794]: wlxc04a0010118a: interface state UNINITIALIZED->ENABLED Nov 10 16:42:02 domain1 hostapd[794]: wlxc04a0010118a: AP-ENABLED Nov 10 16:42:02 domain1 systemd[1]: hostapd.service: Can't open PID file /run/hostapd.pid (yet?) after start: > Nov 10 16:42:02 domain1 systemd[1]: Started Hostapd IEEE 802.11 Access Point.
Result of systemctl status hostapd.service after hostapd restart: hostapd.service - Hostapd IEEE 802.11 Access Point Loaded: loaded (/etc/systemd/system/hostapd.service; enabled; vendor preset: enabled) Active: active (running) since Wed 2021-11-10 17:32:36 UTC; 6min ago Process: 1499 ExecStartPre=/sbin/ip link set wlxc04a0010118a up (code=exited, status=0/SUCCESS) Process: 1514 ExecStart=/usr/sbin/hostapd -B /etc/hostapd/hostapd.conf -P /var/run/hostapd.pid (code=exited, s> Main PID: 1522 (hostapd) Tasks: 1 (limit: 4596) Memory: 816.0K CGroup: /system.slice/hostapd.service └─1522 /usr/sbin/hostapd -B /etc/hostapd/hostapd.conf -P /var/run/hostapd.pid Nov 10 17:32:30 domain1 systemd[1]: Stopping Hostapd IEEE 802.11 Access Point... Nov 10 17:32:30 domain1 systemd[1]: hostapd.service: Succeeded. Nov 10 17:32:30 domain1 systemd[1]: Stopped Hostapd IEEE 802.11 Access Point. Nov 10 17:32:30 domain1 systemd[1]: Starting Hostapd IEEE 802.11 Access Point... Nov 10 17:32:30 domain1 hostapd[1514]: Configuration file: /etc/hostapd/hostapd.conf Nov 10 17:32:34 domain1 hostapd[1514]: Using interface wlxc04a0010118a with hwaddr c0:4a:00:10:11:8a and ssid> Nov 10 17:32:36 domain1 hostapd[1514]: wlxc04a0010118a: interface state UNINITIALIZED->ENABLED Nov 10 17:32:36 domain1 hostapd[1514]: wlxc04a0010118a: AP-ENABLED Nov 10 17:32:36 domain1 systemd[1]: hostapd.service: Can't open PID file /run/hostapd.pid (yet?) after start:> Nov 10 17:32:36 domain1 systemd[1]: Started Hostapd IEEE 802.11 Access Point.
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| What happens when an SD card gets connected Posted: 10 Nov 2021 09:39 AM PST I'm still quite confused as to how this works exactly. When we connect an SD card to a computer running a Linux system, this is my understanding (Please feel free to correct on the smallest of details which are incorrect ) : Linux identifies the device as an SD card by an identifier stored on the SD card. Along with this identifier, there is an SD card controller which takes care about reading and writing from and to the card. In Linux, the SD card shows up as a block device in /dev . An SD card driver will then get loaded into the kernel and connected to use with the device file. This SD card driver takes care about writing and reading to and from the SD card controller on the SD card. Now, when we wish to format the SD card and use a particular filesystem for it such as FAT32, where does this filesystem controller code come into all this? Does it get written onto the card, or just on the Linux computer? Thanks in advance.  |
| Custom system locale results in unreadable output Posted: 10 Nov 2021 09:33 AM PST I try to define a custom locale on Debian Bullseye, and everything is going well until I set the custom locale as the system locale. After I set the custom locale as the system locale output becomes unreadable. Let's install a stock locale as the golden standard $ echo "el_GR.UTF-8 UTF-8" | sudo tee -a /etc/locale.gen $ sudo locale-gen $ LC_ALL=el_GR.utf8 ncal Νοέμβριος 2021 Δε 1 8 15 22 29 Τρ 2 9 16 23 30 Τε 3 10 17 24 Πε 4 11 18 25 Πα 5 12 19 26 Σα 6 13 20 27 Κυ 7 14 21 28
Creating a custom locale I intentionally don't make any customization to demonstrate that the problem doesn't originate from the customization. $ sudo mkdir -p /usr/local/share/i18n/locales/ $ sudo cp /usr/share/i18n/locales/el_GR /usr/local/share/i18n/locales/el_GR@test $ sudo localedef -c -v -f UTF-8 --no-archive -i /usr/local/share/i18n/locales/el_GR@test el_GR.UTF-8@test $ echo "el_GR.UTF-8@test UTF-8" | sudo tee -a /etc/locale.gen $ sudo locale-gen $ LC_ALL=el_GR.utf8@test ncal Νοέμβριος 2021 Δε 1 8 15 22 29 Τρ 2 9 16 23 30 Τε 3 10 17 24 Πε 4 11 18 25 Πα 5 12 19 26 Σα 6 13 20 27 Κυ 7 14 21 28
Everything looks well at the moment. Setting it as the system locale $ sudo update-locale LANG=el_GR.UTF-8@test
and after logging out and logging back in: $ ncal ÎÎ¹Î¿Ï 2021 Îε 1 8 15 22 29 Î¤Ï 2 9 16 23 30 Τε 3 10 17 24 Πε 4 11 18 25 Πα 5 12 19 26 Σα 6 13 20 27 ÎÏ 7 14 21 28 $ LC_ALL=el_GR.utf8 ncal ÎÎ¹Î¿Ï 2021 Îε 1 8 15 22 29 Î¤Ï 2 9 16 23 30 Τε 3 10 17 24 Πε 4 11 18 25 Πα 5 12 19 26 Σα 6 13 20 27 ÎÏ 7 14 21 28
And what about the stock locale? $ sudo update-locale LANG=el_GR.UTF-8
and after logging out and logging back in everything becomes fine with the custom locale as well as with the stock one: $ ncal Νοέμβριος 2021 Δε 1 8 15 22 29 Τρ 2 9 16 23 30 Τε 3 10 17 24 Πε 4 11 18 25 Πα 5 12 19 26 Σα 6 13 20 27 Κυ 7 14 21 28 $ LC_ALL=el_GR.utf8@test ncal Νοέμβριος 2021 Δε 1 8 15 22 29 Τρ 2 9 16 23 30 Τε 3 10 17 24 Πε 4 11 18 25 Πα 5 12 19 26 Σα 6 13 20 27 Κυ 7 14 21 28
What am I doing wrong and how to fix it?  |
| TAR returns 1 on big directories - how to ignore this? Posted: 10 Nov 2021 09:04 AM PST I'm running the following sequence for backup purposes: $> set -o pipefail $> tar -c /vary/large/folder1 /very/large/folder2 | xz ... | gpg ... | aws ... $> echo "${PIPESTATUS[0]} ${PIPESTATUS[1]} ${PIPESTATUS[2]} ${PIPESTATUS[3]}" 1 0 0 0
When I run tar on smaller directories, the return value is always 0. But when I try to backup larger folders (+10G), the return value is always 1. The manpage of tar states: RETURN VALUE 1 Some files differ. If tar was invoked with the --compare (--diff, -d) command line option, this means that some files in the archive differ from their disk counterparts. If tar was given one of the --create, --append or --update options, this exit code means that some files were changed while being archived and so the resulting archive does not contain the exact copy of the file set. What can I do to prevent tar returning 1 which spoils the sequence of my backup script? I want/need to ignore files that have changed during the backup, so how can I ignore files that differ? Is there any "best way" to handle huge directories with tar - how would you solve this error? Thanks in advance.  |
| AppImage - Where is state saved between instances? Posted: 10 Nov 2021 09:22 AM PST If you're running an AppImage application, and you make settings changes to it (or anything else that would change the state of the application), are those changes saved within the AppImage file itself? And if so, how do you preserve those settings upon upgrading to a later version of that AppImage application?  |
| iptables Forwarding and port blocking Posted: 10 Nov 2021 08:34 AM PST I have created the following Network in Virtual Box: Linux Internal PC with 1 Static IP: 10.10.10.2 Linux Gateway/Firewall with 2 Static IP's and 1 NAT: 10.10.10.3 | 11.11.11.2 | NAT Network Card Linux DMZ Server with 1 Static IP: 11.11.11.3 The targets:
1)Internet on 10.10.10.X and 11.11.11.X via Linux Gateway. (Only port 80, 443 allowed to the internet, everything else block)
2)Access to DMZ server from 10.10.10.X only via port 22,80,443 (everything else blocked from Linux Gateway The iptables in Linux Gateway I have until now is: iptables -F #Linux Gateway to Internet from 10.10.10.X iptables -A FORWARD -i enp0s8 -o enp0s3 -j ACCEPT iptables -A FORWARD -i enp0s3 -o enp0s8 -m state --state RELATED,ESTABLISHED -j ACCEPT iptables -t nat -A POSTROUTING -o enp0s3 -j MASQUERADE #Linux Gateway to Internet from 11.11.11.X iptables -A FORWARD -i enp0s9 -o enp0s3 -j ACCEPT iptables -A FORWARD -i enp0s3 -o enp0s9 -m state --state RELATED,ESTABLISHED -j ACCEPT #Linux Gateway to DMZ iptables -A FORWARD -i enp0s8 -o enp0s9 ACCEPT iptables -A FORWARD -i enp0s9 -o enp0s8 -m state --state RELATED,ESTABLISHED -j ACCEPT iptables -t nat -A POSTROUTING -o enp0s9 -j MASQUERADE #Allow only port 80,443 to Internet iptables -A INPUT -p tcp -m tcp -m multiport --dports 80,443 -j ACCEPT iptables -A INPUT -m state --state NEW,ESTABLISHED,RELATED -j ACCEPT iptables -A INPUT DROP iptables -A OUTPUT -m state --state NEW,ESTABLISHED,RELATED -j ACCEPT iptables -A OUTPUT DROP iptables -A FORWARD DROP
I am not sure if its correct and also I have to add the restriction for ports with destination to DMZ.  |
| Autostart script not working in Qtile on Manjaro Posted: 10 Nov 2021 08:01 AM PST I have Qtile installed on Manjaro, and in the config.py I have it set to run and autostart script autostart.sh. However, when I start Qtile it does not run, I get no errors or anything. I have to run the script manually every time I start Qtile. This is what I have in my config.py: from libqtile import hook import os import subprocess @hook.subscribe.startup_once def autostart(): home = os.path.expanduser('~/.config/qtile/autostart.sh') subprocess.call([home])
This is what I have in my autostart.sh #!/bin/bash xrandr --output HDMI1 --left-of eDP1 & nitrogen --restore & picom -f &
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| Implementing DB Security with Linux Posted: 10 Nov 2021 09:47 AM PST I have installed cygwin64 and have been practising linux commands and Shell programming. I am creating a project where I want to restrict file permissions, authenticate user, and execute procedures stored in Database. As I am not very well versed with this, I have been trying different methods. Can I do this in cygwin64? I do not want to download the virtualbox. I could not get administrator priviledges in cygwin64, not even with a run as administrator selection. The prompt remains a $. Please help.  |
| Elementary OS stuck, doesn't boot Posted: 10 Nov 2021 07:35 AM PST 
I have no idea what went wrong. I know how to chroot. I am a student and this is my only computer. I have some urgent work pending so please help me if you can. I have encrypted luks drive.  |
| Unable to connect telnet to mysql listen ip port from remote host Posted: 10 Nov 2021 08:20 AM PST I m able to telnet locally to mysql process like below: I have also made sure MySQL process is listening on all IPs by setting bind-address = 0.0.0.0 as evident below: root@localhost:~# netstat -plutn | grep mysql tcp 0 0 0.0.0.0:33060 0.0.0.0:* LISTEN 39288/mysqld tcp 0 0 0.0.0.0:7306 0.0.0.0:* LISTEN 39288/mysqld
and root@localhost:~# telnet 82.165.32.59 7306 Trying 82.165.32.59... Connected to 82.165.32.59. Escape character is '^]'. >Host 'linux' is not allowed to connect to this MySQL serverConnection closed by foreign host
I opened the firewall port 7306 and reloaded the firewall using the below commands: root@localhost:~# firewall-cmd --zone=public --permanent --add-port=7306/tcp Warning: ALREADY_ENABLED: 7306:tcp success root@localhost:~# firewall-cmd --reload success root@localhost:~# firewall-cmd --list-all public target: default icmp-block-inversion: no interfaces: sources: services: dhcpv6-client ssh ports: 443/tcp 80/tcp 7306/tcp protocols: masquerade: no forward-ports: source-ports: icmp-blocks: rich rules:
However, when telnet from a remote host it fails like below: $ telnet 82.165.32.59 7306 Trying 82.165.32.59... telnet: connect to address 82.165.32.59: Connection timed out
My OS is: root@localhost:~# uname -a Linux localhost 5.4.0-89-generic #100-Ubuntu SMP Fri Sep 24 14:50:10 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux root@localhost:~# lsb_release -a No LSB modules are available. Distributor ID: Ubuntu Description: Ubuntu 20.04.3 LTS Release: 20.04 Codename: focal
I tried restarting the firewall service as below: root@localhost:~# systemctl restart firewalld
I also flushed the IPTABLES using the below script but it did not help: root@localhost:~# cat fw.stop #!/bin/sh echo "Stopping IPv4 firewall and allowing everyone..." ipt="/sbin/iptables" ## Failsafe - die if /sbin/iptables not found [ ! -x "$ipt" ] && { echo "$0: \"${ipt}\" command not found."; exit 1; } $ipt -P INPUT ACCEPT $ipt -P FORWARD ACCEPT $ipt -P OUTPUT ACCEPT $ipt -F $ipt -X $ipt -t nat -F $ipt -t nat -X $ipt -t mangle -F $ipt -t mangle -X $ipt -t raw -F $ipt -t raw -X
Can you please suggest?  |
| Can't restart MariaDB after adding datadir line to my.cnf file Posted: 10 Nov 2021 07:27 AM PST Having a issue getting MariaDB to restart after adding the following line to the [mysqld] section of my.cnf: datadir = /home/mysql
It won't restart. Could this be a permissions issue. This is the directory that holds all my SQL data. Here is what systemctl status mysql.service shows ● mariadb.service - MariaDB database server Loaded: loaded (/usr/lib/systemd/system/mariadb.service; disabled; vendor preset: disabled) Active: failed (Result: exit-code) since Wed 2021-11-10 08:33:00 CST; 36s ago Docs: man:mysqld(8) https://mariadb.com/kb/en/library/systemd/ Process: 14438 ExecStart=/usr/lib/mysql/mysql-systemd-helper start (code=exited, status=1/FAILURE) Process: 14425 ExecStartPre=/usr/lib/mysql/mysql-systemd-helper upgrade (code=exited, status=0/SUCCESS) Process: 14412 ExecStartPre=/usr/lib/mysql/mysql-systemd-helper install (code=exited, status=0/SUCCESS) Main PID: 14438 (code=exited, status=1/FAILURE) Status: "MariaDB server is down" Nov 10 08:33:00 law-amp3 mysql-systemd-helper[14438]: 2021-11-10 8:33:00 0 [Note] /usr/sbin/mysqld (mysqld 10.4.17-MariaDB-log) starting as process 14438 ... Nov 10 08:33:00 law-amp3 mysql-systemd-helper[14438]: 2021-11-10 8:33:00 0 [Warning] Could not increase number of max_open_files to more than 1024 (request: 32214) Nov 10 08:33:00 law-amp3 mysql-systemd-helper[14438]: 2021-11-10 8:33:00 0 [Warning] Changed limits: max_open_files: 1024 max_connections: 151 (was 151) table_cache: 421 (was 2000) Nov 10 08:33:00 law-amp3 mysql-systemd-helper[14438]: 2021-11-10 8:33:00 0 [Warning] Can't create test file /home/mysql/law-amp3.lower-test Nov 10 08:33:00 law-amp3 mysql-systemd-helper[14438]: [87B blob data] Nov 10 08:33:00 law-amp3 mysql-systemd-helper[14438]: 2021-11-10 8:33:00 0 [ERROR] Aborting Nov 10 08:33:00 law-amp3 systemd[1]: mariadb.service: Main process exited, code=exited, status=1/FAILURE Nov 10 08:33:00 law-amp3 systemd[1]: Failed to start MariaDB database server. Nov 10 08:33:00 law-amp3 systemd[1]: mariadb.service: Unit entered failed state. Nov 10 08:33:00 law-amp3 systemd[1]: mariadb.service: Failed with result 'exit-code'.
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| Debian 11 issue with locale: No such file or directory Posted: 10 Nov 2021 07:47 AM PST The problem I encounter with Debian bullseye (v11): If I execute locale -a, I get the following output: locale: Cannot set LC_CTYPE to default locale: No such file or directory locale: Cannot set LC_MESSAGES to default locale: No such file or directory locale: Cannot set LC_COLLATE to default locale: No such file or directory C C.UTF-8 POSIX aa_DJ aa_DJ.iso88591 aa_DJ.utf8 aa_ER aa_ER.utf8 ... zh_TW zh_TW.big5 zh_TW.euctw zh_TW.utf8 zu_ZA zu_ZA.iso88591 zu_ZA.utf8
Also, if I try to use tlmgr (package manager for LateX), I get the following: perl: warning: Setting locale failed. perl: warning: Please check that your locale settings: LANGUAGE = "en_US:fr:en_GB", LC_ALL = "en-US.UTF-8", LC_MESSAGES = "en_US.UTF-8", LC_CTYPE = "en_US.UTF-8", LC_COLLATE = "en_US.UTF-8", LANG = "fr_FR.UTF-8" are supported and installed on your system. perl: warning: Falling back to a fallback locale ("fr_FR.UTF-8"). tlmgr: no action given; try --help if you need it.
I searched the issue, and tried the following: dpkg-reconfigure locales and selecting only used locales (fr utf8, en-us utf8 and en-gb utf8)dpkg-reconfigure locales and selecting all locales (as you can see above)locale-gen- restarting the PC with each change
- editing /etc/default/locale
More information cat /etc/default/locale gives:
# File generated by update-locale LANG=en_US.UTF-8 LANGUAGE=en_US.UTF-8 LC_ALL=en_US.UTF-8 LC_CTYPE=en_US.UTF-8 LC_MESSAGES=en_US.UTF-8 LC_COLLATE=en_US.UTF-8
ls /usr/share/locale/en gives:
LC_MESSAGES
ls /usr/share/locale/en/LC_MESSAGES gives:
accounts-service.mo gtk30-properties.mo iso_3166-2.mo kcoreaddons5_qt.qm kwidgetsaddons5_qt.qm cups-pk-helper.mo gtk30.mo
Questions - Should I reconfigure locales and only select used locales?
- The error message says that it expects file/folder that does not exist. Where should this file/folder be located? in
/usr/share/locale/en? - How to solve this issue (non-blocking, because all applications seem to work, but annoying)?
If you have suggestions for documentations to read to dive deeper on this issue I'm also all hear. Thank you. Edits Questions from @StéphaneChazelas Output of locale locale: Cannot set LC_CTYPE to default locale: No such file or directory locale: Cannot set LC_MESSAGES to default locale: No such file or directory locale: Cannot set LC_ALL to default locale: No such file or directory LANG=fr_FR.UTF-8 LANGUAGE=en_US:fr:en_GB LC_CTYPE="en-US.UTF-8" LC_NUMERIC="en-US.UTF-8" LC_TIME="en-US.UTF-8" LC_COLLATE="en-US.UTF-8" LC_MONETARY="en-US.UTF-8" LC_MESSAGES="en-US.UTF-8" LC_PAPER="en-US.UTF-8" LC_NAME="en-US.UTF-8" LC_ADDRESS="en-US.UTF-8" LC_TELEPHONE="en-US.UTF-8" LC_MEASUREMENT="en-US.UTF-8" LC_IDENTIFICATION="en-US.UTF-8" LC_ALL=en-US.UTF-8
Output of strace locale 2>&1 | grep ENOENT: access("/etc/ld.so.preload", R_OK) = -1 ENOENT (No such file or directory) openat(AT_FDCWD, "/usr/lib/locale/en-US.UTF-8/LC_CTYPE", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory) openat(AT_FDCWD, "/usr/lib/locale/en-US.utf8/LC_CTYPE", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory) openat(AT_FDCWD, "/usr/lib/locale/en-US/LC_CTYPE", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory) openat(AT_FDCWD, "/usr/lib/locale/en-US.UTF-8/LC_MESSAGES", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory) openat(AT_FDCWD, "/usr/lib/locale/en-US.utf8/LC_MESSAGES", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory) openat(AT_FDCWD, "/usr/lib/locale/en-US/LC_MESSAGES", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory) openat(AT_FDCWD, "/usr/lib/locale/en-US.UTF-8/LC_IDENTIFICATION", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory) openat(AT_FDCWD, "/usr/lib/locale/en-US.utf8/LC_IDENTIFICATION", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory) openat(AT_FDCWD, "/usr/lib/locale/en-US/LC_IDENTIFICATION", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
ls /usr/lib/locale gives:
C.UTF-8 locale-archive
Strange dpkg-reconfigure locales output If I'm not wrong, dpkg-reconfigure locales should list locales and say for each of them "up to date" if already generated. But in my case, it re-process each locale and says "done": perl: warning: Setting locale failed. perl: warning: Please check that your locale settings: LANGUAGE = "en_US:fr:en_GB", LC_ALL = "en-US.UTF-8", LC_MESSAGES = "en_US.UTF-8", LC_CTYPE = "en_US.UTF-8", LC_COLLATE = "en_US.UTF-8", LANG = "fr_FR.UTF-8" are supported and installed on your system. perl: warning: Falling back to a fallback locale ("fr_FR.UTF-8"). locale: Cannot set LC_CTYPE to default locale: No such file or directory locale: Cannot set LC_MESSAGES to default locale: No such file or directory locale: Cannot set LC_ALL to default locale: No such file or directory /usr/bin/locale: Cannot set LC_CTYPE to default locale: No such file or directory /usr/bin/locale: Cannot set LC_MESSAGES to default locale: No such file or directory /usr/bin/locale: Cannot set LC_ALL to default locale: No such file or directory Generating locales (this might take a while)... aa_DJ.UTF-8... done aa_DJ.ISO-8859-1... done aa_ER.UTF-8... done aa_ER.UTF-8@saaho... done aa_ET.UTF-8... done af_ZA.UTF-8... done af_ZA.ISO-8859-1... done agr_PE.UTF-8... done ak_GH.UTF-8... done am_ET.UTF-8... done an_ES.UTF-8... done an_ES.ISO-8859-15... done anp_IN.UTF-8... done ar_AE.UTF-8... done ar_AE.ISO-8859-6... done ar_BH.UTF-8... done ar_BH.ISO-8859-6... done ar_DZ.UTF-8... done ar_DZ.ISO-8859-6... done ar_EG.UTF-8... done ar_EG.ISO-8859-6... done ar_IN.UTF-8... done ar_IQ.UTF-8... done ...
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| PXE Server Build Posted: 10 Nov 2021 07:15 AM PST So what if I already have a DHCP server and a DNS Server, How do I build it with out those components? Would DHCP and DNS Conflict with what I already have?  |
| HAPROXY - Redirect request to another server Posted: 10 Nov 2021 08:22 AM PST Through a HAProxy I have to redirect requests of the type http://my server/vo-tcs to a server with IP address 172.22.80.40 (SRV1). I state that on SRV1 the Joomla CMS is installed and it is installed in a subdirectory called vo-tcs. If I do not activate the SEO (within the Joomla configuration) everything works correctly and the requests are of the type http://mioserver/vo-tcs/index.php?option=com_wrapper&view=wrapper&Itemid=155
then everything works correctly. If instead I activate the Joomla SEO and the URL is of the type http://mioserver/vo-tcs/tna
then I get the error message 404 (page not found). Could you give me a hand? I am attaching the configuration. frontend Local_Server mode http bind *:80 acl is_vo-tcs path_beg -i /vo-tcs use_backend be_vo-tcs if is_vo-tcs backend be_vo-tcs mode http reqrep ^([^\ ]*\ /)vo-tcs[/]?(.*) \1\2 http-request set-header X-Forwarded-Port %[dst_port] http-request add-header X-Forwarded-Proto https if { ssl_fc } http-request set-path %[path,regsub(^/?,/vo-tcs/)] option httpchk HEAD / HTTP/1.1rnHost:localhost server web7 172.22.80.40:80
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| bash: trap reaction - different timing Posted: 10 Nov 2021 08:22 AM PST GNU bash, version 4.2.46(2)-release (x86_64-redhat-linux-gnu) [curious ~]# cat ./trap-term #!/bin/bash trap 'echo TRAP' TERM sleep 30 [curious ~]# ./trap-term & sleep 3; kill -TERM %1 [1] 3141 <... pause - 3s> [curious ~]# Terminated TRAP [1]+ Exit 143 ./trap-term
Reaction is immediate (3s)?! [curious ~]# cat ./tt #!/bin/bash ./trap-term & sleep 3; kill -TERM %1 [curious ~]# ./tt <... pause - 3s> [curious ~]# <... pause - 30s> TRAP
Reaction agrees with bash doc: If Bash is waiting for a command to complete and receives a signal for which a trap has been set, the trap will not be executed until the command completes. The question is why the first variant is so much faster than other?? Update: Test in another distro: Ubuntu 20.04.3 LTS (GNU/Linux 4.4.0-19041-Microsoft x86_64); GNU bash, version 5.0.17(1)-release (x86_64-pc-linux-gnu): the same first result with "Terminated" and "TRAP" after 3s @zevzek "there are no jobs in shell scripts"??! curious ~$ cat ./ttj #!/bin/bash ./trap-term & sleep 3; jobs; kill -TERM %1 curious ~$ ./ttj [1]+ Running ./trap-term & curious ~$ TRAP
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| Free up mysql space on low-disk PC Posted: 10 Nov 2021 07:47 AM PST I have a PC with a small disk: Filesystem Size Used Avail Use% Mounted on /dev/root 3.5G 3.1G 249M 93% / devtmpfs 459M 0 459M 0% /dev tmpfs 463M 0 463M 0% /dev/shm tmpfs 463M 36M 428M 8% /run tmpfs 5.0M 8.0K 5.0M 1% /run/lock tmpfs 463M 0 463M 0% /sys/fs/cgroup /dev/mmcblk0p1 63M 25M 38M 40% /boot tmpfs 64M 140K 64M 1% /mnt/ramdisk
I have a simple database, but one of the tables has more than 5 million rows, taking up a lot on such a small record: # ls -lh /var/lib/mysql/datalogger/ total 1.1G ... -rw-rw---- 1 mysql mysql 1.1G Nov 10 09:56 avg_values.ibd ...
My goal, done on other similar computers without so much space occupied (about half in that table) was to run a query that deleted data more than 6 months old. The query is irrelevant to the case. after the query, running optimize NO_WRITE_TO_BINLOG table avg_values; free up ibd space. The problem with the computer in question, is that -as I believe- the available space is very limited, you can not perform queries on such a large table (by cache, I understand), causing instability in communications, even when the query has a limit: MariaDB [datalogger]> select * from avg_values limit 10; ERROR 2006 (HY000): MySQL server has gone away No connection. Trying to reconnect... Connection id: 5 Current database: datalogger ERROR 2013 (HY000): Lost connection to MySQL server during query
With other smaller tables there are usually no problems (although it also indicates error): MariaDB [datalogger]> select * from raw_values; ERROR 2006 (HY000): MySQL server has gone away No connection. Trying to reconnect... Connection id: 5 Current database: datalogger +----+---------------------+-------------------+------+-------+ | id | timestamp | channel | raw | value | +----+---------------------+-------------------+------+-------+ | 1 | 2021-11-10 09:46:51 | AI1 | 1 | 0.011 | | 2 | 2021-11-10 09:46:51 | AI2 | 1 | 0.011 | | 3 | 2021-11-10 09:46:51 | AI3 | 2 | 0.022 | | 4 | 2021-11-10 09:46:51 | AI4 | 2 | 0.022 | | 5 | 2021-11-10 09:46:51 | pyr1_sensor1_data | 113 | 113 | | 6 | 2021-11-10 09:46:51 | pyr1_body_temp | 42 | 42 | | 7 | 2021-11-10 09:46:51 | pyr2_sensor1_data | NULL | NULL | | 8 | 2021-11-10 09:46:51 | pyr2_body_temp | NULL | NULL | | 9 | 2021-11-10 09:46:46 | AI1 | 1 | 0.011 | | 10 | 2021-11-10 09:46:46 | AI2 | 1 | 0.011 | | 11 | 2021-11-10 09:46:46 | AI3 | 2 | 0.022 | | 12 | 2021-11-10 09:46:46 | AI4 | 2 | 0.022 | | 13 | 2021-11-10 09:46:46 | pyr1_sensor1_data | 115 | 115 | | 14 | 2021-11-10 09:46:46 | pyr1_body_temp | 42 | 42 | | 15 | 2021-11-10 09:46:46 | pyr2_sensor1_data | NULL | NULL | | 16 | 2021-11-10 09:46:46 | pyr2_body_temp | NULL | NULL | | 17 | 2021-11-10 09:46:52 | AI1 | 1 | 0.011 | | 18 | 2021-11-10 09:46:52 | AI2 | 1 | 0.011 | | 19 | 2021-11-10 09:46:52 | AI3 | 2 | 0.022 | | 20 | 2021-11-10 09:46:52 | AI4 | 2 | 0.022 | | 21 | 2021-11-10 09:46:52 | pyr1_sensor1_data | 112 | 112 | | 22 | 2021-11-10 09:46:52 | pyr1_body_temp | 42 | 42 | | 23 | 2021-11-10 09:46:52 | pyr2_sensor1_data | NULL | NULL | | 24 | 2021-11-10 09:46:52 | pyr2_body_temp | NULL | NULL | +----+---------------------+-------------------+------+-------+ 24 rows in set (0.02 sec)
Is there any way I can run these queries, especially with this little disk in order to free up space?  |
| How to Send a Signal or Data to C++ Program from Bash Script Posted: 10 Nov 2021 07:18 AM PST As the title states I would like a to be able to send a signal, alert, message, or something to a C++ program while it is executing from a bash script. I have seen some solutions where a script will start the program with arguments, but I need it to occur while the program is already up and running. Is there any way to do that? Basically while the script runs in the background if an error occurs I would like it to be reported to the program directly, rather than be logged somewhere in the OS. I am using Redhat 8. Thank you  |
| Splitting a small file into 512 byte segments changes it, but splitting it in 1k segments doesn't Posted: 10 Nov 2021 08:48 AM PST So I'm trying to split a 64MB file FileCarve.001 into 512 byte segments (each block is 512 bytes long). I need to make sure the file has the same data when split into smaller files, so I cat all the files to standard out and pipe it into sha256sum (there's a lot of files, so I need to do this with find and xargs). Splitting the file in 512 byte segments seems to garble the data when the output gets split by the split command. $ dd if=FileCarve.001 bs=512 | split -b512 - splits/img 131072+0 records in 131072+0 records out 67108864 bytes (67 MB, 64 MiB) copied, 4.10824 s, 16.3 MB/s $ sha256sum FileCarve.001 3e64100044099b10060f5ca3194d4d60414941c7cb26437330aba532852a60cd FileCarve.001 $ find splits/ -type f -print0 | xargs -0 cat | sha256sum 25b37f28204895e5d0b1cb160c5fa599d15188baf7e529ccc92a10fdb3f0515a -
But splitting the file in 1 kilobyte segments (1000 bytes) seems to work just fine. $ dd if=FileCarve.001 bs=512 | split -b1k - splits/img 131072+0 records in 131072+0 records out 67108864 bytes (67 MB, 64 MiB) copied, 2.06029 s, 32.6 MB/s $ sha256sum FileCarve.001 3e64100044099b10060f5ca3194d4d60414941c7cb26437330aba532852a60cd FileCarve.001 $ find splits/ -type f -print0 | xargs -0 cat | sha256sum 3e64100044099b10060f5ca3194d4d60414941c7cb26437330aba532852a60cd -
Why are they different? Is there something I don't understand about the way blocks work on a storage device? In response to a comment: I did clear out the split/ directory on each run.  |
| How to update R on Linux mint Posted: 10 Nov 2021 07:19 AM PST I am not able to update R version 3.* on 4.* What I have done according to this page: I checked /etc/apt/sources.list #deb cdrom:[Linux Mint 19.2 Tina - Release amd64 20190729]/ bionic contrib main non-free
I ran: sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys E298A3A825C0D65DFD57CBB651716619E084DAB9 [sudo] heslo pro linux: Executing: /tmp/apt-key-gpghome.H9fjVZrS2l/gpg.1.sh --keyserver keyserver.ubuntu.com --recv-keys E298A3A825C0D65DFD57CBB651716619E084DAB9 gpg: klíč 51716619E084DAB9: „Michael Rutter <marutter@gmail.com>" 1 nový podpis gpg: Celkový počet zpracovaných klíčů: 1 gpg: nové podpisy: 1 linux@linux-HP-Pavilion-dv6-Notebook-PC:~$ sudo add-apt-repository 'deb https://cloud.r-project.org/bin/linux/ubuntu focal-cran40/' linux@linux-HP-Pavilion-dv6-Notebook-PC:~$ sudo apt install r-base Načítají se seznamy balíků… Hotovo Vytváří se strom závislostí Načítají se stavové informace… Hotovo r-base je již nejnovější verze (3.4.4-1ubuntu1). Následující balíky byly nainstalovány automaticky a již nejsou potřeba: libllvm9 linux-headers-4.15.0-20 linux-headers-4.15.0-20-generic linux-image-4.15.0-128-generic linux-image-4.15.0-20-generic linux-image-4.15.0-74-generic linux-modules-4.15.0-128-generic linux-modules-4.15.0-20-generic linux-modules-4.15.0-74-generic linux-modules-extra-4.15.0-128-generic linux-modules-extra-4.15.0-20-generic linux-modules-extra-4.15.0-74-generic Pro jejich odstranění použijte „sudo apt autoremove". 0 aktualizováno, 0 nově instalováno, 0 k odstranění a 245 neaktualizováno. linux@linux-HP-Pavilion-dv6-Notebook-PC:~$ sudo apt install r-base Načítají se seznamy balíků… Hotovo Vytváří se strom závislostí Načítají se stavové informace… Hotovo r-base je již nejnovější verze (3.4.4-1ubuntu1). Následující balíky byly nainstalovány automaticky a již nejsou potřeba: libllvm9 linux-headers-4.15.0-20 linux-headers-4.15.0-20-generic linux-image-4.15.0-128-generic linux-image-4.15.0-20-generic linux-image-4.15.0-74-generic linux-modules-4.15.0-128-generic linux-modules-4.15.0-20-generic linux-modules-4.15.0-74-generic linux-modules-extra-4.15.0-128-generic linux-modules-extra-4.15.0-20-generic linux-modules-extra-4.15.0-74-generic Pro jejich odstranění použijte „sudo apt autoremove". 0 aktualizováno, 0 nově instalováno, 0 k odstranění a 245 neaktualizováno. linux@linux-HP-Pavilion-dv6-Notebook-PC:~$ r -- version Příkaz 'r' nebyl nalezen, ale je možné jej nainstalovat pomocí: sudo apt install r-cran-littler linux@linux-HP-Pavilion-dv6-Notebook-PC:~$ R --version R version 3.4.4 (2018-03-15) -- "Someone to Lean On" Copyright (C) 2018 The R Foundation for Statistical Computing Platform: x86_64-pc-linux-gnu (64-bit) R is free software and comes with ABSOLUTELY NO WARRANTY. You are welcome to redistribute it under the terms of the GNU General Public License versions 2 or 3. For more information about these matters see http://www.gnu.org/licenses/.
The version is still 3.4.4.  |
| What is an effective way to automatically append file extensions to extensionless files? Posted: 10 Nov 2021 08:02 AM PST I wrote a bash script today during my lunch break that finds extensionless files in a directory and appends a file extension to those files. The script is relatively long because I added a bunch of flags and stuff like directory selection and whether to copy or overwrite the file, but the meat and potatoes of its functionality can be replicated simply with this: #recursively find files in current directory that have no extension for i in $(find . -type f ! -name "*.*"); do #guess that extension using file extfile=$(file --extension --brief $i) #select the first extension in the event file spits something weird (e.g. jpeg/jpe/jfif) extawk=$(echo $extfile | awk -F/ '{print $1}') #copy the file to a file appended with the extension guessed from the former commands cp -av $i $i.$extawk done
It's a bit tidier in my actual script—I just wanted to split commands up on here so I could comment why I was doing things. My question: Using find in combination with file in the manner I have chosen is likely not the most fool-proof way to go about doing this—what is the best way to recursively guess and append extensions for a bulk group of diverse filetypes among several directories?  |
| fail2ban / FirewallD error: invalid port/service `1-65535' specified Posted: 10 Nov 2021 08:57 AM PST I am running a CentOS 8.4 server. When I do a systemctl status firewalld I see the daemon is active and running, but I see the following error repeated five times: ERROR: '/usr/sbin/iptables-restore -w -n' failed: iptables-restore v1.8.4 (nf_tables): invalid port/service `1-65535' specified FirewallD version is 0.8.2. The error disappears when I stop fail2ban. Any thoughts on what may be causing this? Thank you.  |
| Taskwarrior Question : Howto show completed projects? Posted: 10 Nov 2021 08:06 AM PST to show all completed tasks the command is in Taskwarrior : task status:completed all but what is the command for showing only the completed projects (not including the completed tasks !)  |
| How to mount a xfs volume to centOS 7 ec2 instance /home directory Posted: 10 Nov 2021 08:05 AM PST I created t2.medium instance and attached ebs volume to the instance Here are some useful information. sudo pvs
PV VG Fmt Attr PSize PFree /dev/xvdb1 vg_home lvm2 a-- <200.00g 0
sudo vgs
VG #PV #LV #SN Attr VSize VFree vg_home 1 1 0 wz--n- <200.00g 0
sudo lvs
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert lv_home vg_home -wi-a----- <200.00g
lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT xvda 202:0 0 50G 0 disk └─xvda1 202:1 0 50G 0 part / xvdb 202:16 0 200G 0 disk └─xvdb1 202:17 0 200G 0 part └─vg_home-lv_home 253:0 0 200G 0 lvm
lsblk -lf
NAME FSTYPE LABEL UUID MOUNTPOINT xvda xvda1 xfs 0356e691-d6fb-4f8b-a905-4230dbe62a32 / xvdb xvdb1 LVM2_member qSmSpW-MRuF-WrUE-jJL8-N182-xOgA-57kdkB vg_home-lv_home xfs b4fadb7e-714c-4cdd-a5dd-43df5ef19b84
So I need to mount vg_home-lv_home to /home directory. I can mount this volume by running sudo mount /dev/vg_home/lv_home /home Then its mounted. After that, I terminated my ssh session and try to ssh again. ssh -i <key> centos@<ec2_public_ip>. I can't ssh into ec2 instance, error is Permission denied (publickey,gssapi-keyex,gssapi-with-mic). It makes sense, because I mounted /dev/vg_home/lv_home to /home. and .ssh folder has gone from /home Then I restarted the ec2 instance and I can ssh it again. So my question is how can I mount xfs volume to /home directory? I created a mountpoint /mnt/home and copied /home then unmounted from mnt/home and mounted to /home. Then I can't connected to ec2 instance at all (with restart). So what is the best practice/method to mount a volume to ec2 instance /home directory? -Thank you  |
| Excessive CPU usage with vlock as tmux lock-command Posted: 10 Nov 2021 09:49 AM PST I am running tmux, configured to lock my sessions via /etc/tmux.conf: set-option -g lock-command "/usr/bin/vlock -c" set-option -g lock-after-time 300
(The aim is to replace GNU screen -- to see if it behaves better with the various terminal emulators I use -- which has idle 300 lockscreen in its config.) Every now and again, if I allow a session to lock and leave it for a few days, I can return to the session to find that vlock is consuming most of my CPU (top shows %CPU at 96-98): PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 19002 root 20 0 48176 8888 1040 R 98.7 1.8 13:00.60 vlock
While this is happening, a large number of log entries occur in both /var/log/secure and /var/log/audit/audit.log -- one or two every second, e.g.: ==> /var/log/audit/audit.log <== type=USER_AUTH msg=audit(1502738594.043:4705): pid=19002 uid=0 auid=0 ses=14 subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 msg='op=PAM:authentication grantors=? acct="root" exe="/usr/bin/vlock" hostname=? addr=? terminal=pts/0 res=failed' ==> /var/log/secure <== Aug 14 20:23:14 hostname.local vlock[19002]: pam_unix(vlock:auth): auth could not identify password for [root] Aug 14 20:23:14 hostname.local vlock[19002]: pam_succeed_if(vlock:auth): requirement "uid >= 1000" not met by user "root"
None of the tty consoles appear to be locked -- they all appear logged out. The tmux process appears to be the owner of the vlock process (at least, according to ps): # ps -ef | grep vlock root 19002 4102 0 Aug09 ? 00:21:35 /usr/bin/vlock -c root 25318 24147 0 20:41 pts/7 00:00:00 grep --color=auto vlock # ps -ef | grep 4102 root 4102 1 0 Aug02 ? 00:00:00 tmux new-session -t root root 19002 4102 0 Aug09 ? 00:22:25 /usr/bin/vlock -c
I guess the ? suggests that both tmux and vlock have 'divorced' themselves somehow from their respective terminals, but I don't know how to resolve, short of kill -9 19002. I also guess that the audit.log entries mean a missing SELinux exception, but this only seems to happen after a few days of vlock running, where I'd have thought a problem there would always happen. Again, I guess the pam_succeed_if messages in secure suggest that something is attempting to validate username/password and failing because the UID of root is less than 1000, but I can't find the process doing that. Besides, I have no users with UID >= 1000, because I haven't set other users up yet. Again, I would expect this to be a problem all the time, rather than just after a few days. If I connect via SSH and allow tmux to either reattach or merge sessions (tmux new-session -t $USER), I can see the same session as before; if that session then idles for 5 mins, I can use another SSH session to see the second instance of vlock, this time owned by tmux, and sshd: root 26751 22688 0 21:02 pts/4 00:00:00 /usr/bin/vlock -c root 22688 22681 0 20:22 pts/4 00:00:00 tmux new-session -t root root 22681 838 0 20:22 ? 00:00:00 sshd: root@pts/4 root 838 1 0 Aug02 ? 00:00:00 /usr/sbin/sshd -D
Pertinent versions, that I can think of: - /etc/redhat-release:
CentOS Linux release 7.3.1611 (Core) - uname -a:
Linux server.local 3.10.0-514.26.2.el7.x86_64 #1 SMP Tue Jul 4 15:04:05 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux - tmux -V:
tmux 1.8 - vlock -v:
1.15.5 I'm not wedded to vlock if a more-suitable alternative exists in Base or EPEL. If not, I guess I'll try setting lock-command to tmux detach-client to force a disconnection rather than a lock, but I did like the locking paradigm. What else can I look at to prevent this spin-wait problem? For its perceived faults, GNU Screen never seemed to take up resources like this... Update #1 OK, I can reliably recreate this now: - Login to the server via SSH
- Create/attach the
tmux session (I do this in my login script, FWIW) - Allow that session to idle and start locking
- Kill the SSH client on my workstation (i.e. an unclean shutdown of my client)
vlock will start spinning I suppose I can get around it using the following in a script, which I execute using a per-minute cron job: ps -ef \ | grep -F '/usr/bin/vlock' \ | grep -Fv 'grep' \ | awk '$6 == "?" { print $2 }' \ | xargs -r kill -9
...but that feels like a bit of a hack. Better suggestions are welcome.  |
| Installing Packages in PyCharm Posted: 10 Nov 2021 09:05 AM PST I'm using Mint Cinnamon (very new) and tryign to get some packages in PyCharm. When I use the package installer for Numpy or Pandas I get the error message: collect2: error: ld returned 1 exit status
And if I try to upgrade pip in the terminal I get: PermissionError: [Errno 13] Permission denied: 'download.py'
What steps should I take to get these packages into PyCharm. Project interpreter is '/usr/bin/python3.4  |
| How to script with systemd-cgtop? Posted: 10 Nov 2021 09:01 AM PST The manpage for systemd-cgtop says that if there is no attached tty it will do one iteration and then print it out, saying that this would be useful in scripts. However when I try to do this from a script, it does not work as advertised: #!/bin/bash line=$(systemd-cgtop|grep ezdose) echo $line
Running the script as so: $ bash test.sh (hangs with no output)
How do you work this?  |
| Why only one active group at a time? Posted: 10 Nov 2021 08:22 AM PST As far as I understand the users in Unix system can belong to multiple groups and one of them will become the primary group for that user. Others will be supplementary groups. All of this User/Group infrastructure is facilitated by /etc/group and /etc/passwd files. Now group permission of the user is determined exclusively by the active group which can be changed by newgrp command. The active group on login is the primary group defined in /etc/passwd file. So the question is what is the fundamental reason on why the designers chose to have this concept of a single active group even though allowing the user to have more than one supplementary groups? What would be the issue if all the groups were active simultaneously?  |
| mpd to remote dlna Posted: 10 Nov 2021 09:21 AM PST I currently use an mpd with 4 configured outputs, wired to speakers in the ceilings as home-made "multiroom" audio system. I would like to add wireless speakers, e.g. one like this. The question is: How can I tell mpd that there is an output which is in fact remote a dlna/upnp (even aiyplay would be fine) ip-device ? Is it possible at all ? Edit 1: I found a way, though through pulseaudio and not dlna (which could be a use for one of my Raspberry Pis).  |
| Case insensitive search in man pages Posted: 10 Nov 2021 08:59 AM PST Is there a way to search man pages case-insensitively? Using the '/' search feature matches exact case.  |
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