/ - rtt - IT Resource

  • 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 a........
  • 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


    <p>It's a basic script that reads the file &quot;ips.txt&quot; in the current directory and then creates a corresponding ifcfg file</p> <p>&nbsp;</p> <p>&nbsp;</p> <p><code>#!/bin/bash<br /> GATEWAY=192.168.1.1</code></p> <p><code>NETMASK=255.255.255.0</code></p> <p>device=eth0</p> <p><code><br /> counter=0<br /> for ips in `cat ips.txt`; do<br........
  • 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 but I chose images from the 'Integrated" on motherboard version as it was all I 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 I used (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 ALL files 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........
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