hostnamectl; # tested on Icon name: computer-desktop Chassis: desktop Operating System: Debian GNU/Linux 10 (buster) Kernel: Linux 4.19.0-8-amd64 Architecture: x86-64 su – root; # become root apt update apt install rfkill rfkill list all 0: phy0: Wireless LAN Soft blocked: […]
Update: 2020-02 added “geany” is there an ideal IDE for every task? Nope. Of course just as programming languages every IDE has their pros and cons. (build for a specific purpose? might serve other purposes also) There is not a […]
ls -lah –color –time-style=+%F # will output year-month-day like: 2020-02-06 # if one needs the actual TIMESTAMP: go –full-time # ls -lah –color –full-time will output time in format: # 2020-02-04 11:37:57.619196543 +0100 # can put it into (debian/ubuntu/mint…) vim […]
all infos about one’s harddisk: # tested on: hostnamectl Static hostname: centos.localdomain Operating System: CentOS Linux 7 (Core) CPE OS Name: cpe:/o:centos:centos:7 Kernel: Linux 4.15.9 Architecture: x86-64 # software needed: install smart monitoring tools yum install smartmontools.x86_64 # nice overview: […]
firewall & pinguin: iptables where do thou go? it is said that when using “ip-sets” iptables and nftables achieve almost same performance (amounts of ips possible to block, without server becoming slow/unresponsive) Redhat and nftables on DDoS “so the only […]
situation: one is userA but wants to ssh login to server with ipv4: 123.123.123.123 via userB (dedicated user for that server/task). so what one does is: make sure one can login as userB than as userA: userA: ssh -v -i […]
very very nice actually. visit the site: https://www.wieistmeineip.de/ 1) setup an ssh server 2) make sure u can login with the given user ssh -N -D 9090 -p22 user@yourserver.com now config firefox proxy like this: click “ok” then visit the […]
mdadm -E /dev/sd[a-z] # -E, –examine # Print contents of the metadata stored on the named device(s). # Note the contrast between –examine and –detail. # –examine applies to devices which are components of an array, while # –detail applies […]
some jpgs are badly compressed, taking 5-10MBytes each! a little nifty cool tool let’s you batch recompress WARNING! Always test things out before applying it to your original data! # become root su – root # install jpegoptim apt install […]
list all current ips that are connected to port 587 netstat -anp | grep :587 | grep ESTABLISHED
One way to do it is: while read p; do echo “$p” done <peptides.txt As pointed out in the comments, this has the side effects of trimming leading whitespace, interpretting backslash sequences, and skipping the trailing line if it’s missing […]
yum install ascii # or apt install ascii ascii Usage: ascii [-dxohv] [-t] [char-alias…] -t = one-line output -d = Decimal table -o = octal table -x = hex table -h = This help screen -v = version information Prints […]
# tested on yum install inxi inxi -b System: Host: hp.centos Kernel: 5.1.15 x86_64 bits: 64 Desktop: MATE 1.16.2 Distro: CentOS Linux release 7.6.1810 (Core) Machine: Type: Server System: HP product: ProLiant DL360 G6 v: N/A serial: XXXXXXXXX Mobo: N/A […]
bc is a nice calculator that one can use under linux terminal. a good exercise: count from 0 to 255 and convert it to binary # install # debian/ubuntu apt install bc # fedora/redhat/centos yum install bc # run bc […]
when one is happy with the setup of a linux system (config and scripts) one might want to backup those settings and restore it on a different machine or if things go haywire restore on the current machine. cat /scripts/backup/config_scripts.sh […]
this is, because this is, because, when one logs in, and opens another shell as the same user, the last bash process to quit, will save to ~/.bash_history overwrite history. to avoid this add: (TEST IN PROGRESS (UNTESTED)!) # Avoid […]
it is actually possible to open a text file in less, then switch over to vim (without exiting less) and when done with editing, switch back to less. less /open/this/file/for/viewing # switch over to vim :v # now one is […]
tar gz (single core) -> tar pigz (multi core) tar might be old, but still a great program for archiving files manpage: tar.man.txt to get multi core usage for compression (faster) the user tells tar to use a different compression […]
# install apt install zip; # deb based yum install zip; # rpm based # encrypt all files (not filenames) with password zip –encrypt -r file.encrypted.zip /folder/to/encrypt
if you want to search all files (file size smaller than 256MBytes) for a match in it’s sha1 checksum: #!/bin/bash find / -type f -size -256M | while read fname; do checksum=$(sha1sum “$fname”); CHECKSUM=${checksum^^}; echo $CHECKSUM; done write it to […]
WARNING! BE VERY VERY CAREFUL! YOU CAN DESTROY YOUR SYSTEM! so better use a system that is not production important/not a live server. use a laptop that has NOTHING ATTACHED TO IT! (unplug all USB Sticks and external USB Drives) […]
will do exactly that: last -F # -F Print full login and logout times and dates. # output will look like this # username (who logged in) ip (from which was logged in) duration of session username pts/0 123.123.123.123 Tue […]
cat /scripts/crontab_show_all.sh for user in $(cut -f1 -d: /etc/passwd); do echo $user; crontab -u $user -l; done outputs a nice list like this: in format: user command root no crontab for root actualuser * * * * * echo “stuff” […]
aim: in software development, step debugging is a very nice way to look at your code and see if it does what it should. i wondered, if such a thing exists for shell / bash scripts. develop shell bash scripts […]
arrays are pretty useful variables that hold key:value data pairs, per default the “key” is an integer number, BUT: as shown there can also be associative arrays, meaning the index can be any string (needs bash version4) this script demonstrates […]
bash games – you must be kidding me! no! bash is a serious language X-D while it might not be your first choice when it comes to creating games. it’s awesome what people put together on the command line! bash […]
WARNING! BACKUP YOUR MACHINE! UNTESTED! before running this script change to your new web root: /home/UserName/web/domain.com/public_html then run it like /scripts/install_wordpress.sh it tries to: download and unpack the latest wordpress into the current directory disable xmlrpc.php disable wp-cron.php requirements: a […]
it is super slow, but for copying small files it works. if /mnt/cifs/here is owned by non-root user, also non-root users are allowed to mount. (which is rather tricky with mount cifs) # setup software apt install sshfs yum install […]
tested with: tested with/on: Static hostname: CentOS1.localdomain Operating System: CentOS Linux 7 (Core) Kernel: Linux 4.15.9 Architecture: x86-64 bash -version GNU bash, version 4.2.46(2)-release (x86_64-redhat-linux-gnu) ping -V ping utility, iputils-s20160308 usage: /scripts/count_host_uptime.sh domain.com cat /scripts/count_host_uptime.sh domain.com #!/bin/bash # ping -c […]
start a second console and as root: watch kill -USR1 $(pgrep ^dd)