- ILUG-D - lists.fsci.in

1D1C - semodule
by Dhanasekar 04 Sep '23

04 Sep '23

semodule - Manage SELinux policy modules To view the policy module loaded by SELinux $ sudo semodule -l To view the apache policy module $ sudo semodule -l | grep apache To disable the zabbix policy module $ sudo semodule -d zabbix regards, T.Dhanasekar

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1D1C - firewall-offline-cmd
by Dhanasekar 03 Sep '23

03 Sep '23

firewall-offline-cmd - firewalld offline command line client It should be used only if the firewalld service is not running To add a port to firewall daemon when firewalld is offline $ sudo firewall-offline-cmd --port=80:tcp $ sudo firewall-offline-cmd --port=443:tcp $ sudo firewall-offline-cmd --port=3306:tcp To remove a port to firewall daemon when firewalld is offline $ sudo firewall-offline-cmd --remove-port=80:tcp $ sudo firewall-offline-cmd --remove-port=443:tcp $ sudo firewall-offline-cmd --remove-port=3306:tcp $ sudo firewall-offline-cmd --remove-port=53:tcp To list all the ports under all the zones $ sudo firewall-offline-cmd --list-all regards, T.Dhanasekar

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1D1C - PS1
by Dhanasekar 02 Sep '23

02 Sep '23

PS1 - is the current bash shell prompt To display current bash shell prompt setting $ echo $PS1 To print the current settings from your ~/.bashrc $ grep PS1 ~/.bashrc To customise the bash prompt to ilugc > temporarily $ PS1="\e[1;32milugc> \e[m" To display customised colours for bash prompt $ PS1="\e[1;32milugc> \e[m" $ PS1="\e[1;33milugc> \e[m" $ PS1="\e[1;35milugc> \e[m" $ PS1="\e[1;36milugc> \e[m" $ PS1="\e[1;37milugc> \e[m" $ PS1="\e[1;38milugc> \e[m" To make the above bash prompt permanently $ vim ~/.bashrc comment the old entries with PS1 then add the entry PS1="\e[1;32milugc> \e[m" : wq! save and exit then $ source ~/.bashrc To make system wide $ sudo vim /etc/profile comment the old entries with PS1 then add the entry PS1="\e[1;32milugc> \e[m" : wq! save and exit then # source /etc/profile To set emoji in bash prompt $ PS1="\e[1;32milugc🎄 \e[m" PS1="\e[1;32milugc🦌 \e[m" regards, T.Dhanasekar

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1D1C - set
by Dhanasekar 01 Sep '23

01 Sep '23

set - is used to set and unset certain flags or settings within the shell environment syntax $ set [options] To display a list of all system settings $ set To print help options $ set --help To turn on the debugging information in a shell script $ set -x To turn off the debugging information $ set +x To disable the default behavior of Bash $ set -C To stop a script immediately $ set -e regards, T.Dhanasekar

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1D1C - rdfind
by Dhanasekar 31 Aug '23

31 Aug '23

rdfind - finds duplicate files To install rdfind $ sudo apt install rdfind To find duplicate file in a directory testdir $ rdfind /home/venus/testdir it will create a results.txt file To print help options $ rdfind --help To delete duplicate files in a current directory $ rdfind -deleteduplicates true . regards, T.Dhanasekar

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1D1C - rmlint
by Dhanasekar 30 Aug '23

30 Aug '23

rmlint - find duplicate files and other space waste efficiently To find duplicate files in test dir $ pwd /home/venus/test create same content with 3 files test$ ls file1.txt file2.txt file3.txt $ rmlint /home/venus/test # Duplicate(s): ls '/home/venus/test/file1.txt' rm '/home/venus/test/file2.txt' rm '/home/venus/test/file3.txt' ==> Note: Please use the saved script below for removal, not the above output. ==> In total 3 files, whereof 2 are duplicates in 1 groups. ==> This equals 12 B of duplicates which could be removed. ==> Scanning took in total 0.146s. Wrote a sh file to: /home/venus/test/rmlint.sh Wrote a json file to: /home/venus/test/rmlint.json 2. To print help options $ rmlint --help 3. To open rmlint in GUI $ rmlint --gui /home/venus/test regards, T.Dhanasekar

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1D1D - fdupes
by Dhanasekar 29 Aug '23

29 Aug '23

fdupes - finds duplicate files in a given set of directories create file1.txt $ cat file1.txt i love linux i love python create file2.txt with same content as file1.txt $ cat file2.txt i love linux i love python To find duplicate contents with different file names in the current directory $ fdupes . To search for duplicates recursively under every directory $ fdupes -r /home To find the size of duplicates in the current dir $ fdupes -S . To find duplicates in more than one directory $ fdupes /home/<username>/Downloads /home/<username>/Documents To display a summary of all information related to duplicate files in the current directory $ fdupes -m . $ cat filea.txt hello $ cat fileb.txt hello $ cat filec.txt hello To remove duplicate files in the current directory $ fdupes -d . Set 1 of 1: 1 [ ] ./filea.txt 2 [ ] ./fileb.txt 3 [ ] ./filec.txt if we want to keep file 2 and delete 1 and 3 ( Preserve files [1 - 3, all, help] )=2 then ( Preserve files [1 - 3, all, help] ): prune and hit ENTER ( No duplicates remaining; type 'exit' to exit program ):exit To preserve the first instance of a file in every set of duplicate files and want to ignore the prompt $ fdupes -d -N . To display help options $ fdupes --help regards, T.Dhanasekar

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1D1C - sshpass
by Dhanasekar 28 Aug '23

28 Aug '23

sshpass - noninteractive ssh password provider To install sshpass $ sudo apt-get install sshpass To pass ssh passwords from a file .secret to ssh login $ echo 'myPassword' > .ssh_secrets $ chmod 0400 .secrets $ sshpass -f ".ssh_secrets" ssh user@remote_server_ip To pass ssh password direct to ssh login $ sshpass -p 'ssh_server_password' ssh username@remote_server_ip To make backup of all databases without password $ sshpass -f ".db_secrets" mysqldump -u root -p --all-databases > all-databases_`date +"%Y-%B-%d_%R"`.sql To make backup using rsync $ sshpass -f ".ssh_secrets" rsync -a backup/ user_name@remote_server_ip :/home/test/backup regards, T.Dhanasekar

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1D1C - identify
by Dhanasekar 27 Aug '23

27 Aug '23

identify - describes the format and characteristics of one or more image files. To get the details of images $ identify pic1.jpg $ identify pic2.jpeg $ identify pic3.png regards, T.Dhanasekar

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1D1C - at , atq , atrm
by Dhanasekar 26 Aug '23

26 Aug '23

at, batch, atq, atrm - queue, examine, or delete jobs for later execution To execute a command at 13.00 hours $ at 13.00 at> df -Th > df.txt at> CTRL+D The command $ df -Th will executed and stored in df.txt at 13.00 hours To list the jobs in queue with job numbers $ atq To cancel the jobs in queue $ atrm <job_number> To execute a command at 14.00 hours $ at 14.00 at> free -h > free.txt at> CTRL+D The command $ free -h will executed and stored in free.txt at 14.00 hours check with $ atq regards, T.Dhanasekar

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