• How to configure OpenDKIM on Linux with Postfix and setup bind zonefile


    This guide assumes you have a working Postfix server and want it to sign with DKIM. There are a few things we have to understand to make all of this work though, which require you to be familiar with DNS as well. 1.) Install OpenDKIM apt install opendkim systemctl enable opendkim 2.) Edit /etc/opendkim.conf Syslog yes SyslogSuccess yes Mode&nbs........
  • talib/_ta_lib.c:747:10: fatal error: ta-lib/ta_defs.h: No such file or directory


    If you are installing ta-lib for Python and get this error then you can normally solve it by manually getting the ta-lib source files and compiling. tar -zxvf ta-lib-0.4.0-src.tar.gz cd ta-lib;./configure;make;make install Collecting ta-lib Downloading https://files.pythonhosted.org/packages/39/6f/6acaee2eac6afb2cc6a2adcb294080577f9983fbd2726395b9047c4e13ec/TA-Lib-0.4.26.tar.gz (272kB) &nbs........
  • CentOS 6 EOL yum repo won't work Error: Cannot find a valid baseurl for repo: base Solution


    yum update Loaded plugins: fastestmirror Setting up Install Process Determining fastest mirrors YumRepo Error: All mirror URLs are not using ftp, http[s] or file. Eg. Invalid release/repo/arch combination/ removing mirrorlist with no valid mirrors: /var/cache/yum/x86_64/6/base/mirrorlist.txt Error: Cannot find a valid baseurl for repo: base You have mail in /var/spool/mail/root ........
  • ffmpeg how to concat and join two video clips


    This normally works but if not use my mencoder solution if the output video does not play past the joined time. the contents of list.txt need to look like this: file somefile.mp4 file somefile2.mp4 then run ffmpeg ffmpeg -f concat -i list.txt -c copy CME-2-router-dial-peer-final.mp4 The result is almost instant joining since there is no video processing since we are........
  • apcupsd how to setup and monitor APC UPS units


    It really seems limited in that it can mainly give you the things you would see on the physical unit such as load etc.. wget https://downloads.sourceforge.net/project/apcupsd/apcupsd%20-%20Stable/3.14.14/apcupsd-3.14.14.tar.gz?r=https%3A%2F%2Fsourceforge.net%2Fprojects%2Fapcupsd%2Ffiles%2Flatest%2Fdownload&ts=1598115866 tar -zxvf apcupsd-3.14.14.tar.gz cd apcupsd-3.14.14 [root@somebox apcupsd-3.14.14]# ./conf........
  • How To Install python 3.4 3.5 and up on Linux with wine - Working Solution


    This is sure simple if you follow the guide but it took a lot of hacking around to make this work on Debian/Ubuntu! Now before you ask why bother running wine and python, the reason is because Python executables are NOT cross-platform. If you run pyinstaller in Linux, that binary will only run on Linux and the same if you do it in Windows. So it is preferable if you have a single environment that you can create Linux and Windows binaries from rather than running 2 separate........
  • how to use ifplugd in Linux to execute a command or script when a NIC cable is unplugged or plugged in


    It is fairly simple to use once you know how to use it. However, the tricky thing is that by default it doesn't seem to be active or listen on any interface on manually specified. How To Install ifplugd First we install ifplugd sudo apt install ifplugd Let's enable it on our desired device(s) vi /etc/default/ifplugd set this line as so:........
  • python import docx error


    sudo pip3 install python-docx [sudo] password for : Downloading/unpacking python-docx Downloading python-docx-0.8.10.tar.gz (5.5MB): 5.5MB downloaded Running setup.py (path:/tmp/pip_build_root/python-docx/setup.py) egg_info for package python-docx no previously-included directories found matching 'docs/.build' warning: no previously-included files matching '.DS_Store' foun........
  • python 3 pip cannot install mysql module


    python3 testserver.com-car-scraping.py html.txt Traceback (most recent call last): File "testserver.com-car-scraping.py", line 5, in import mysql.connector ImportError: No module named 'mysql' For some reason it won't install properly even though I have the mysql client on this machine installed too. Solution: You need the mys........
  • Bind / named not responding to queries solution


    By default bind will not respond to outside queries for security reasons. In most distributions you will find the default in /etc/named.conf looks like this at the top under options: listen-on port 53 { 127.0.0.1; }; listen-on-v6 port 53 { ::1; }; directory "/var/named";........
  • Cisco Unified Communications Manager / CUCM IP 8.6,10,12 Install Error Solution


    Install Errors on Version 12: This error happened on QEMU emulator version 2.11.1 pve-qemu-kvm_2.11.1-5 on Proxmox/Debian but installing on QEMU.12 on Centos 6 did not produce the error. *Update it is not related to the OS or QEMU version. This happened in Centos 6 too after a second install. What really causes this even though you successfully install........
  • Cisco Unified Communications Manager 12 Install Errors on Proxmox/KVM


    The strange thing is that usually the first install or two will work on any new machine but then it suddenly won't. I had this experience on QEMU 2.13 on a different machine. There is something finicky or buggy about the CUCM installer even when choosing the same virtual hardware specs. qemu-kvm command: /usr/libexec/qemu-kvm -version QEMU PC emulator version 0.12.1 (qemu-kvm-0.12.1.2-2.506.el6_10.1), Copyright (c) 2003-2008 Fabrice Bellard ........
  • How To Boot Cisco CUCM UCSInstall 8.6, 10, 11 and 12 on KVM/Proxmox


    The key thing is that you must use a "machine"id of "pc-1.3" or it will say your hardware is not supported. Additionally you MUST use a virtio disk or you will get a ks_pre.sh error as soon as the install starts (a look at logs will show it can't find a disk). This is funny because even though the OS finds the disk and an fdisk -l shows it, it looks like the script looks for a /dev/vda device (virtio) and nothing else, so if you didn't use Virtio as you........
  • Bash Script How To Manipulate Text/Strings By Searchig and Replacing Natively


    # a single first slash means first occurrence # format=${haystack/needle/replacement} # if you use a double first slash it means ALL occurrences # format=${haystack//needle/replacement} email=${file/.txt-marked/} In the example above we are searching in the variable $file for ".txt-marked" and replacing with nothing (the empty part after the last / means we are replacing with n........
  • grep regular expression match number range between specific numbers


    grep -E servers1[2-6] somefile.txt The 1 before the [ bracket means that the number must start with one and can be between 1 and [2-6] or in plain English between 12-16. ........
  • bash how to print out lines of text within a range from the first occurrence


    #get line number of occurrence in text file and then print out x lines from that point #get the line number of the first occurrence of our search text linenumber=`grep -n "someuniqueitem" inventory.txt|head -n1|cut -d ":" -f 1` #linestop represents how many lines after the occurring line we want to print out in this case "20" linestop=$((linenumber+20)) # sed prints out the line range we want f........
  • HP DL385 G7 Linux BIOS Update Flash


    wget https://downloads.linux.hpe.com/repo/spp/rhel/6/x86_64/current/CP017004.scexe --2018-08-16 05:11:16-- https://downloads.linux.hpe.com/repo/spp/rhel/6/x86_64/current/CP017004.scexe Resolving downloads.linux.hpe.com (downloads.linux.hpe.com)... 15.249.152.85 Connecting to downloads.linux.hpe.com (downloads.linux.hpe.com)|15.249.152.85|:443... connected. HTTP request sent, awaiting response... 200 OK Length: 1525561 (1.5........
  • Debian Mint Ubuntu compiling xmr-stak


    sudo apt-get install libcurl4-openssl-dev git build-essential autotools-dev autoconf libcurl3 sudo apt-get install libcurl4-gnutls-dev git clone https://github.com/wolf9466/cpuminer-multi sudo apt-get install cmake libpthread-* libmicrohttpd-dev libssl-dev libhwloc-dev git clone https://github.com/fireice-uk/xmr-stak-cpu.git make install cd bin chmod +x xmr-stak-cpu ./xmr-stak -O xmr........
  • mail command line examples of how to send an email using Linux / Unix and the Bash Shell or Scripting


    A simple way that may work for a lot of people who just need basic output for their scripts or daemons to announce an action is this: echo "body or message" | mail -s "realtechtalk.com" user@domain.com If you want to send a text file as the body just do this instead: mail -s "realtechtalk.com" user@domain.com < /tmp/sometxtfile.txt These are some ve........
  • bash find line and replace howto


    First find the line number: awk '/what you are searching for/{ print NR; exit }' input-file 86 Now use sed to replace it: sed -i 86s/.*/"your replacement text"/ $file Here is a full sample script to automate it: file=some/f........
  • Centos 5.9 Working Vault Repo file


    Centos 5 is not supported running yum will produce an error like this: YumRepo Error: All mirror URLs are not using ftp, http[s] or file. Eg. Invalid release/ removing mirrorlist with no valid mirrors: /var/cache/yum/base/mirrorlist.txt Error: Cannot find a valid baseurl for repo: base Solution - Update this file CentOS-Base.repo # CentOS-Base.repo........
  • ffmpeg trouble concatenating similar but different files


    When things go wrong your video is basically unplayable or the first video plays fine and then freezes when moving on to the next. Generally if both videos weren't produced with the exact 100% same settings you will have issues. You can try the basic concat but it often won't work right. Solution for me: My example uses 3 videos in total so "n=3" and a=1 to include audio. ffmpeg -threads 12 -i file1.mp4 -........
  • ffmpeg Linux Mint download, compile and install howto


    #if you have nvidia make sure you install the nvidia-cuda-toolkit so hardware acceleration can be used wget http://ffmpeg.org/releases/ffmpeg-3.3.2.tar.bz2 tar -jxvf ffmpeg-3.3.2.tar.bz2 cd ffmpeg-3.3.2/ ./configure --disable-yasm install prefix /usr/local source path ........
  • php read file into variable


    php read file into variable $content = file_get_contents(home.html); Otherwise if you want to get the source code of the PHP file, it's the same as a .txt file: $content = file_get_contents('/path/to/phpfile.php'); You can also get from URLs: $content = file_get_contents('http://someurl.com/file.txt');........
  • grep only certain file types howto


    This can save a lot of time, otherwise grep will go through an entire directory recursively searching every type of file but what if you are sure you only need to search txt or php files? grep -r -i --include=*.php "what you are searching for" /the/path/to/search........
  • OpenVZ mass ip update


    The file ipupdate.txt should look like this: ip.ip.ip.ip ctid while read -r; do ip=$REPLY setip=`echo $ip|awk '{print $1}'` ctid=`echo $ip|awk '{print $2}'` echo "vzctl set $ctid --ipadd $setip --save" vzctl set $ctid --ipadd $setip --save done < ipupdate.txt........
  • blocked for more than 120 seconds issues with iowait and timeout on Live Linux distribution while writing to physical disk


    This happened while an mdadm array was syncing, all access from writing a new blank file to opening a small .txt file was very slow: [222117.312078] kjournald starting. Commit interval 5 seconds [222117.685060] EXT3-fs (md0): using internal journal [222117.685096] EXT3-fs (md0): mounted filesystem with ordered data mode [222122.376847] kjournald starting. Commit interval 5 seconds [222122.602825] EXT3-fs (md2): using internal jour........
  • wget ignore robots.txt howto


    wget -e robots=off It is as simple as the above and this is something one must watch out carefully when using wget because you may think you have archived or downloaded content when you never did due to a nofollow/robots.txt statement.........
  • How to manually save bash history


    This is useful in the case you are not properly logged in via an OpenVZ session or even a normal SSH session that you fear may go down(if the connection is broken the history is not saved). Save your bash_history like this: history -w ~/.bash_history You can always change the above to another file eg /tm........
  • Installing zoneminder on Ubuntu/Debian Linux Howto


    sudo apt-get install zoneminder [sudo] password for one: Reading package lists... Done Building dependency tree Reading state information... Done The following packages were automatically installed and are no longer required: libuser-perl python-evince kdebase-apps kwrite unixodbc libgnomeprint2.2-data python-soappy vgabios python-metacity hddtemp python-mediaprof........
  • Centos/obfsproxy errors


    I never did get it working, it is too bad as obfsproxy should really be an option and integrated into the OpenVPN client and server or something similar: yum -y install python-pip python-devel No package python-pip available. #install the EPEL repo python-pip install obfsproxy python-pip install obfsproxy -bash: python-pip: command not found pip install obfsproxy &........
  • sed linux bash how to remove non-ASCII english characters


    sed -i 's/[d128-d255]//g' file.txt........
  • sed print specific line number


    sed is the easiest way and you just specifiy the line number with the "-n #p" file.txt So for example below 2p means print the second line of names.txt sed -n 2p names.txt What Are you Looking At, Mr. Bear?........
  • Centos OpenDKIM & Postfix Setup Guidel


    #from epel repo yum -y install opendkim chkconfig opendkim on cd /etc/opendkim/keys opendkim-genkey -vd mail.server.com opendkim-genkey: generating private key opendkim-genkey: private key written to default.private opendkim-genkey: extracting public key opendkim-genkey: DNS TXT record written to default.txt ........
  • dir2slideshow Centos rpm requirements


    yum -y install dvdauthor ffmpeg mjpegtools sox bc rpm -ivh dvd-slideshow-0.8.4-2.noarch.rpm Preparing... ########################################### [100%] 1:dvd-slideshow ########################################### [100%] /usr/bin/dir2slideshow: line 553: bc: command not f........
  • bash script delete all non-English characters


    #remove non english characters from file: sed -i 's/[d128-d255]//g' file.txt........
  • Centos automatic ifcfg-eth0 scripts based on list of IPs from bash


    It's a basic script that reads the file "ips.txt" in the current directory and then creates a corresponding ifcfg file     #!/bin/bash GATEWAY=192.168.1.1 NETMASK=255.255.255.0 device=eth0 counter=0 for ips in `cat ips.txt`; do........
  • LVM Tutorial how to create a Physical Volume (PV), Volume Group (vg), and a Logical Volume (LV) within it


    # first we need a physical volume which we use the pvcreate tool to create # I create mine on /dev/sdb3 pvcreate /dev/sdb3 dev_is_mpath: failed to get device for 8:19 Physical volume "/dev/sdb3" successfully created # pvdisplay shows the newly created volume pvdisplay "/dev/sdb3" is a new physical volume of "1.35 TiB" --- NEW Physical volume --- PV N........
  • Linux shuf program bash script get random line from file


    shuf -n 1 /path/to/your/file.txt The above will give you a random line from the file using the "shuf" command.........
  • Linux Bash grep howto find line number that contains the result


    cat Xorginfo.txt|grep -nr "xserver-xorg" Result: 9: sudo apt-get remove --purge xserver-xorg 13: sudo apt-get install xserver-xorg 17: sudo dpkg-reconfigure xserver-xorg........
  • rpmforge Centos 6 how to install


    rpm --import http://apt.sw.be/RPM-GPG-KEY.dag.txt i686: rpm -ivh http://packages.sw.be/rpmforge-release/rpmforge-release-0.5.2-2.el6.rf.i686.rpm x64: rpm -ivh http://packages.sw.be/rpmforge-release/rpmforge-release-0.5.2-2.el6.rf.x86_64.rpm ........
  • Dell Perci 6/i Firmware Upgrade Guide Tutorial


    One thing to remember is that you need MegaCli to do the flashing. You also need the correct file,I tried at least 2 different Perc 6 firmwares from Dell that kept getting rejected as corrupt by MegaCli(they were really the wrong version). I have an external PCI-E Dell 6 Perc/I butI chose images from the 'Integrated" on motherboard version as it was allI could find. They are different, and below is my first time finding success.........
  • Dell Perc 6/i cannot downgrade


    I flashed an LSI Logic firmware to it and it broke the BIOS (cannot do Ctrl+R) for booting purposes but allows other functionality to work normally. I tried downgrading to a Dell firmware for Perc 6i but it won't work, not even with MegaCli wget http://downloads.dell.com/FOLDER00416606M/1/SAS-RAID_Firmware_W83M2_LN32_6.3.1-0003_A14.BIN --2013-08-26 12:53:39-- http://downloads.dell.com/FOLDER00416606M/1/SAS-RAID_Firmware_W83M2_LN32_6.3.1-0003_A14.BIN Resolvi........
  • LSI MegaRAID Adventures, Guide and HowTo


    LSi Megaraid At first it was configured as a RAID 0, then I deleted the Virtual Disk Group. I thought both drives would be shown and detected in Linux as sda and sdb but it actually shows nothing. To make them work you have to hit Ctrl+R before the system boots (when prompted) and create a Virtual Disk Group. In my case I created each one as RAID 0 (with a single drive only) as I just wanted JBOD but there is no such option or default in these Dell Pe........
  • rpmforge Centos 6 x64 howto install


    rpm --import http://apt.sw.be/RPM-GPG-KEY.dag.txt rpm -ivh http://packages.sw.be/rpmforge-release/rpmforge-release-0.5.2-2.el6.rf.x86_64.rpm Retrieving http://packages.sw.be/rpmforge-release/rpmforge-release-0.5.2-2.el6.rf.x86_64.rpm Preparing... ########################################### [100%] 1:rpmforge-release #############........
  • Execute Local Bash Scripts remotely by SSH


    for ip in `cat fixlist.txt`; do sudo -u apache ssh root@$ip "`cat iptablesrules.sh`" done In the above example we are going to execute the commands within the local file "iptablesrules.sh" on all the machines in "fixlist.txt". This is a great way of performing server maintenance in a clustered or cloud environment.........
  • bash how to read a single line or filenames with spaces solution


    This happens all the time, you are reading from a textfile which has spaces eg: datainfo 00 datainfo 11 If you do loop on it like this: for info in `cat $file`; do echo "info=$info" done It will treat datainfo and 00 as two separate lines: info=datainfo info=00 Obviously that's not what we want and there are many weird solutions in bash bu........
  • bash linux extract specific lines from a file


    start=1 increment=5 lines=`cat linesfile.txt|sed -n "$start","$increment"p` The secret here is the power of sed. Basically the example above would take the first 5 lines from the file. You could change it though to say take 20 lines starting from the 5th line by adjusting the start and increment values.........
  • Login and download all files script


    This is very handy if you're too busy and don't have time to download whatever files you need. The -D specifies the domains allowed, this is because I specified -H which means foreign hosts are allowed, if you don't restrict them you'll end up going to the whole internet via ads and other links just like a search Engine would follow. -l 0 specifies to go deep, to as many levels as possible/as exist. -e robots=off is important because robots.txt often says you can't vie........
  • Thunderbird How-To Copy/Backup/Restore Accounts and Settings to Another Computer


    The best way is to use rsync, I've set it up so it doesn't copy unnecessary files, or at least ones I'm sure aren't needed. Here is the rsync command Iused (adapt to your specific Thunderbird profile location): rsync -hazv user@remotehost.com:/home/user/.thunderbird/sbrer.default/* /home/user/.thunderbird/4nyb0.default/ --exclude=global* --exclude=Cache --exclude=ImapMail --exclude=Mail This is a great way to get your e-mail accounts going on a new c........
  • sed print specific line from file using Linux/Bash


    It may be hard to find by Googling by it's really quite simple and quicker than reading dozens of man page entries. sed -n 5p somefile.txt Just replace the 5 with whatever line you want to be printed.........
  • Linux how to use find recursively to find certain types of files/extensions


    Normally if you're in a certain directory you could do: find *.txt and it will work as expected, but it won't work recursively through child directories, here's the correct way to do it: find . -type f -name *.txt The "-type f" is optional because that means only files, but we could have specified d for directory etc... The above command will work recursively as you'd expect. In that way I find "find" to be un........
  • Drupal 6.2 Install and how to move install to root/non-subdirectory


    drup 6.2 install $cd drupgoodinst3883/ [ drupgoodinst3883]$ ls CHANGELOG.txt cron.php index.php INSTALL.pgsql.txt INSTALL.txt MAINTAINERS.txt modules robots.txt sites update.php xmlrpc.php COPYRIGHT.txt includes INSTALL.mysql.txt install.php LICENSE.txt misc&........
  • Convert doc images/jpg/jpeg to PDF


    Use "ImageMagick" which can be installed easily on most UNIX/Linux distros. Remember that it will go with the standard file listing to determine the order but I believe you can manually specify multiple jpg's in the arguments. Convert image/jpg to PDF convert *.jpg yourpdf.pdf This is a very handy and free tool. Convert DOC/TXT documents to PDF If you wanted to convert a .doc file or text........
  • Updating yum repos for DAG /etc/yum.repos.d


    Updating yum repos for DAG /etc/yum.repos.dIn /etc/yum.repos.d [quote:96456b2ab9]Create any file such as "CentOS-Dag.repo" in /etc/yum.repos.d[/quote:96456b2ab9] Add the following to the above file: [code:1:96456b2ab9] [dag] name=Dag RPM Repository For Red Hat Enterprise Linux baseurl=http://dag.atrpms.net/redhat/el$releasever/en/$basearch/dag/ http://dag.freshrpms.net/redhat/e........
  • MySQL Error "ERROR 1045 (28000): Access denied for user"


    This happened with a select statement which writes the result to an external file. I didn't remember the privilege "FILE" must be granted on *.* for this to work successfully, it wasn't actually an authentication issue as it implies since I was already in the SQL prompt and doing the query. SELECT some_id FROM sometable INTO OUTFILE '/tmp/result.txt'........
  • Linux How to Search for text within any file using Linux/Unix - Use GREP


    It's actually very simple and "grep" makes it as easy as possible. I'll outline a few common scenarios and provide some examples. Say you want to search ALLfiles within the current directory (and inside/deeper) for the text "phpinfo()" grep -R "phpinfo()" * If you want to search only certain files such as only .txt you would do this instead: grep -R "phpinfo()" *.txt As you ca........
  • Latest Articles

  • Cloned VM/Server/Computer in Linux won't boot and goes to initramfs busybox Solution
  • How To Add Windows 7 8 10 11 to GRUB Boot List Dual Booting
  • How to configure OpenDKIM on Linux with Postfix and setup bind zonefile
  • Debian Ubuntu 10/11/12 Linux how to get tftpd-hpa server setup tutorial
  • efibootmgr: option requires an argument -- 'd' efibootmgr version 15 grub-install.real: error: efibootmgr failed to register the boot entry: Operation not permitted.
  • Apache Error Won't start SSL Cert Issue Solution Unable to configure verify locations for client authentication SSL Library Error: 151441510 error:0906D066:PEM routines:PEM_read_bio:bad end line SSL Library Error: 185090057 error:0B084009:x509 certif
  • Linux Debian Mint Ubuntu Bridge br0 gets random IP
  • redis requirements
  • How to kill a docker swarm
  • docker swarm silly issues
  • isc-dhcp-server dhcpd how to get longer lease
  • nvidia cannot resume from sleep Comm: nvidia-sleep.sh Tainted: Linux Ubuntu Mint Debian
  • zfs and LUKS how to recover in Linux
  • [error] (28)No space left on device: Cannot create SSLMutex Apache Solution Linux CentOS Ubuntu Debian Mint
  • Save money on bandwidth by disabling reflective rpc queries in Linux CentOS RHEL Ubuntu Debian
  • How to access a disk with bad superblock Linux Ubuntu Debian Redhat CentOS ext3 ext4
  • ImageMagick error convert solution - convert-im6.q16: cache resources exhausted
  • PTY allocation request failed on channel 0 solution
  • docker error not supported as upperdir failed to start daemon: error initializing graphdriver: driver not supported
  • Migrated Linux Ubuntu Mint not starting services due to broken /var/run and dbus - Failed to connect to bus: No such file or directory solution