April 2023 - ILUG-D - lists.fsci.in

1D1C - ufw
by Dhanasekar 20 Apr '23

20 Apr '23

ufw - program for managing a netfilter firewall To check ufw status $ sudo ufw status To enable ufw $ sudo ufw enable To disable ufw $ sudo ufw disable To show ufw rules, along with their numbers $ sudo ufw status numbered To reset ufw to its default state $ sudo ufw reset To view firewall reports $ sudo ufw show added $ sudo ufw show raw To set ufw logging levels $ sudo ufw logging on $ sudo ufw logging high $ sudo ufw logging medium $ sudo ufw logging low $ sudo ufw logging full To allow service $ sudo ufw allow openssh To deny service $ sudo ufw deny openssh To view all application profiles $ sudo ufw app list To get more information about a particular profile and defined rules $ sudo ufw app info 'Apache' To reject outgoing FTP connections $ sudo ufw reject out ftp To add a new rule at a specific number $ sudo ufw insert 1 allow 80/tcp $ sudo ufw insert 2 allow 443/tcp To Delete rules by specifying their numbers $ sudo ufw status numbered $ sudo ufw ufw delete 1 (will delete above rule allow 80/tcp) To Deleting rules by service $ sudo ufw delete allow ftp $ sudo ufw delete allow openssh To allow or deny a specific port for a given IP address $ sudo ufw allow from 192.168.122.100 to any port 8081 $ sudo ufw deny from 192.168.122.100 to any port 8080 To allow an entire subnet $ sudo ufw allow from 10.0.1.0/16 To Allow Network Subnets to Specific Port $ sudo ufw allow from 192.168.1.0/24 to any port 22 To Allow Specific Network Interface $ sudo ufw allow in on eth1 to any port 22 To open all ports for a particular IP address $ sudo ufw allow from 192.168.122.100 To allow all ports in a range by specifying a port range $ sudo ufw allow 20:450/tcp To get a numbered list of added rules $ sudo ufw status numbered To check all added rules before starting the firewall $ sudo ufw show added To Allow only TCP traffic over HTTP/80 $ sudo ufw allow http/tcp $ sudo ufw allow 80/tcp To deny incoming FTP traffic $ sudo ufw deny ftp/tcp $ sudo ufw deny 21/tcp To add a new rule to allow SSH $ sudo ufw allow ssh $ sudo ufw allow 22/tcp To rate limiting service $ sudo ufw limit ssh/tcp To print verbose $ sudo ufw status verbose To reload ufw $ sudo ufw reload To Dry Run UFW Rules $ sudo ufw --dry-run enable regards, T.Dhanasekar

1 0

1D1C - unalias
by Dhanasekar 19 Apr '23

19 Apr '23

unalias - is used to remove entries from the current user’s list of aliases To list all aliases $ alias or $ alias -p if user had an alias named h for the history command alias could be removed $ unalias h To remove all aliases from the current session $ unalias -a regards, T.Dhanasekar

1 0

1D1C - ulimit
by Dhanasekar 18 Apr '23

18 Apr '23

ulimit - is a built-in Linux shell command that allows viewing or limiting system resource amounts that individual users consume Syntax $ ulimit [flags][limit] To set the physical memory size in kilobytes $ ulimit -m 10000 To view the detailed soft limits for the current user $ ulimit -Sa To view the detailed hard limits for the current user $ ulimit -Ha To find the resource amount that the current user has access to use $ ulimit To get a detailed report with all resource limits for the current user $ ulimit -a To limit the process number to 10 $ ulimit -u 10 To set the maximum file size that a user can make $ ulimit -f 100 To limit maximum virtual memory $ ulimit -v 1500 To limits the number of simultaneously opened files $ ulimit -n 10 To display maximum users process $ ulimit -u To show maximum memory size limit $ ulimit -v To display the Hard limit $ ulimit -Hn To display Soft Limit $ ulimit -Sn To check out the max scheduling priority of the current user $ ulimit -e To check the maximum stack size of the current user $ ulimit -s To report the time each process is allowed to run $ ulimit -t To check out how many file descriptors a process $ ulimit -n To check out the help options $ ulimit --help regards, T.Dhanasekar

1 0

1D1C - udevadm
by Dhanasekar 17 Apr '23

17 Apr '23

udevadm - is used to manage udev. It takes various subcommands, each of which performs a certain task to modify the behavior of the systemd-udevd daemon and related components To get help options $ udevadm --help $ udevadm info --help $ udevadm trigger --help $ udevadm settle --help $ udevadm control --help $ udevadm monitor --help $ udevadm test --help $ udevadm test-builtin --help To query the Udev database for the device path of /dev/vda1 $ udevadm info --query=path --name=/dev/vda1 To query the device attributes from the udev database $ udevadm info /dev/vda1 To query the Udev database for all device information for /dev/vda1 $ udevadm info --query=all --name=/dev/xvda $ udevadm info --query=all --name=/dev/xvda1 To print all sysfs properties of /dev/vda1 $ udevadm info --attribute-walk --name=/dev/vda $ udevadm info --attribute-walk --name=/dev/vda1 To Trigger all udev rules $ sudo udevadm trigger To Reload all udev rules $ sudo udevadm control --reload-rules To List attributes of a device $ udevadm info --attribute-walk --path /dev/vda1 To Monitor all device events $ udevadm monitor To Print uevents sent out by the kernel $ udevadm monitor --kernel To Print device events after being processed by udev $ udevadm monitor --udev regards, T.Dhanasekar

1 0

1D1C - type
by Dhanasekar 16 Apr '23

16 Apr '23

type - is used to display information about the command type syntax $ type [OPTIONS] FILE_NAME To find the type of ls command $ type ls To find the type of wc command $ type wc $ type type To display more than one argument $ type df free sleep head To display the command is an alias, keyword or a function and path of an executable $ type -a pwd $ type -a ls To print a single word describing the type of the command $ type -t ls $ type -t pwd $ type -t df $ type -t du $ type -t while To display the name of the disk file which would be executed by the shell $ type -p bash To search the PATH for an executable file on the disk even if the command is not file $ type -P pwd To suppress shell function lookup $ type -f while $ type -f ls $ type -f pwd regards, T.Dhanasekar

1 0

computer parts
by PETER REGELOUS 15 Apr '23

15 Apr '23

Dear Forum Team Please let me have your take on the below used pricey? Good weekends to 1 + all. Peter Regelous via UK ---------------------------------------------------------------------------------------- @ Seeing below 8GB (2x4GB) 1600mhz Corsair Vengeance RAM £15 • Radeon HD 6950 Graphics Card £60 • msi P55-GD55 motherboard With Intel i5-650 Costa Rica 3.28GHz processor £60 • GS800 PSU £50 • Freezer pro 7 Rev.2 heatsink £10 For whole lot £180

1 0

1D1C - tune2fs
by Dhanasekar 15 Apr '23

15 Apr '23

tune2fs - is used to manipulate the filesystem parameters of a ext 2/3/4 type file system syntax $ sudo tune2fs option device To list file system parameters $ sudo tune2fs -l /dev/vda1 To set the volume label $ sudo tune2fs -L my_vol /dev/vda1 To find out maximum mount count and mount count $ sudo tune2fs -l /dev/vda1 | grep -i mount To set maximum mount count $ sudo tune2fs -c 80 /dev/vda1 To Display Check Interval of a filesystem $ sudo tune2fs -l /dev/vda1 | grep interval To set time intervals between two filesystem checks $ sudo tune2fs -i 5m /dev/vda1 $ sudo tune2fs -i 5d /dev/vda1 $ sudo tune2fs -i 5w /dev/vda1 To disable filesystem check on reboot set the maximum mount count to -1 or 0. $ sudo tune2fs -c 0 /dev/vda1 $ sudo tune2fs -i 0 /dev/vda1 To set mount counts $ sudo tune2fs -C 30 /dev/vda1 To Set the last-mounted directory $ sudo tune2fs -M mount_mydir /dev/vda1 To Set the last time checked of a filesystem $ sudo tune2fs -T now /dev/vda1 To Change the error behavior of a filesystem $ sudo tune2fs -e continue /dev/vda1 To generate a new random UUID of the filesystem $ sudo tune2fs -U random /dev/vda1 regards, T.Dhanasekar

2 1

bluetooth keyboards
by PETER REGELOUS 14 Apr '23

14 Apr '23

Dear Forum Team Is it true that not many bluetooth keyboards would come with a dongle these days as you don't need it. it just uses the bluetooth built into most motherboards now, or a 3rd party dongle. The types that pair with dongles generally use some other RF protocol. Please let me have your take on the above. Good week-ends to 1 + all. Peter Regelous via UK

1 0

1D1C - tty
by Dhanasekar 14 Apr '23

14 Apr '23

tty - print the file name of the terminal connected to standard input $ tty /dev/pts/0 To Print nothing, only return an exit status. $ tty -s regards, T.Dhanasekar

1 0

1D1C - tsort
by Dhanasekar 13 Apr '23

13 Apr '23

tsort - perform topological sort To perform topological sort $ cat demo.txt a b c d e f g z b c d h $ tsort demo.txt To redirect output to a file $ tsort > demo_out.txt regards, T.Dhanasekar

1 0

2024

2023

2022

2021

ILUG-D April 2023