Commands using head (314)

  • Find the 10 users that take up the most disk space

    In OSX you would have to make sure that you "sudo -s" your way to happiness since it will give a few "Permission denied" errors before finally spitting out the results. In OSX the directory structure has to start with the "Users" Directory then it will recursively perform the operation. Your Lord and master, Mematron Show Sample Output


    1
    sudo -s du -sm /Users/* | sort -nr | head -n 10
    mematron · 2012-09-13 10:15:23 4
  • True Random Dice Roll


    1
    echo $(</dev/urandom tr -dc 1-6 | head -c1)
    unixmonkey40000 · 2012-09-21 08:38:51 7
  • Generate a 18 character password, print the password and sha512 salted hash

    Generate a 18 character password from character set a-zA-Z0-9 from /dev/urandom, pipe the output to Python which prints the password on standard out and in crypt sha512 form. Show Sample Output


    1
    cat /dev/urandom | tr -dc 'a-zA-Z0-9' | fold -w 18 | head -1 | python -c "import sys,crypt; stdin=sys.stdin.readline().rstrip('\n'); print stdin;print crypt.crypt(stdin)"
    cnyg · 2012-11-09 00:40:22 4
  • generate 30 x 30 matrix

    Replaces hexdump with the more succint xxd, and the sed was unnecessarily complex.


    1
    xxd -p /dev/urandom |fold -60|head -30|sed 's/\(..\)/\1 /g'
    psifertex · 2013-02-19 22:18:52 4
  • Generate password


    1
    tr -dc 'A-Za-z0-9!@#$%^&*' < /dev/urandom | fold -w 12 | head -n 1
    opexxx · 2013-03-15 13:20:32 82
  • Display 16 largest installed RPMs in size order, largest first

    Interesting to see which packages are larger than the kernel package. Useful to understand which RPMs might be candidates to remove if drive space is restricted. Show Sample Output


    1
    rpm -qa --queryformat '%{size} %{name}-%{version}-%{release}\n' | sort -k 1,1 -rn | nl | head -16
    mpb · 2013-03-19 21:10:54 6
  • most used unix commands


    1
    awk '{print $1}' ~/.bash_history | sort | uniq -c | sort -rn | head -n 10
    nesses · 2013-05-03 16:24:30 6
  • Get IP address from domain

    I'm not sure how reliable this command is, but it works for my needs. Here's also a variant using grep. nslookup www.example.com | grep "^Address: " | awk '{print $2}' Show Sample Output


    1
    nslookup www.example.com | tail -2 | head -1 | awk '{print $2}'
    wsams · 2013-09-05 20:26:45 11
  • Prints the latest modified files in a directory tree recursively

    Sorts by latest modified files by looking to current directory and all subdirectories Show Sample Output


    1
    find . -name '*pdf*' -print0 | xargs -0 ls -lt | head -20
    fuats · 2013-10-03 21:58:51 9
  • Create a bunch of dummy text files


    1
    for i in `seq 1 4096`; do tr -dc A-Za-z0-9 </dev/urandom | head -c8192 > dummy$i.rnd; done
    BoxingOctopus · 2013-11-11 21:27:15 8
  • Create a bunch of dummy text files

    Using the 'time' command, running this with 'tr' took 28 seconds (and change) each time but using base64 only took 8 seconds (and change). If the file doesn't have to be viewable, pulling straight from urandom with head only took 6 seconds (and change)


    1
    for i in {1..4096}; do base64 /dev/urandom | head -c 8192 > dummy$i.rnd ; done
    pdxdoughnut · 2013-11-12 00:36:10 9
  • Download latest NVIDIA Geforce x64 Windows driver

    Download latest NVIDIA Geforce x64 Windows7-8 driver from Nvidia's website. Pulls the latest download version (which includes beta). This is the "English" version. The following command includes a 'sed' line to replace "english" with "international" if needed. You can also replace the starting subdomain with "eu." "uk." and others. Enjoy this one liner! 1 character under the max :) wget "us.download.nvidia.com$(wget -qO- "$(wget -qO- "nvidia.com/Download/processFind.aspx?psid=95&pfid=695&osid=19&lid=1&lang=en-us" | awk '/driverResults.aspx/ {print $4}' | cut -d "'" -f2 | head -n 1)" | awk '/url=/ {print $2}' | sed -e "s/english/international/" | cut -d '=' -f3 | cut -d '&' -f1)" Show Sample Output


    1
    wget "us.download.nvidia.com$(wget -qO- "$(wget -qO- "nvidia.com/Download/processFind.aspx?psid=95&pfid=695&osid=19&lid=1&lang=en-us"|awk '/driverResults.aspx/ {print $4}'|cut -d "'" -f2|head -n 1)"|awk '/url=/ {print $2}'|cut -d '=' -f3|cut -d '&' -f1)"
    lowjax · 2013-11-21 03:04:59 11
  • Find last reboot time

    Specific to OSX. Show Sample Output


    1
    sysctl -a | grep boottime | head -n 1
    lgarron · 2014-01-24 13:03:48 7
  • Find 10 largest files in git history


    1
    git verify-pack -v .git/objects/pack/pack-*.idx | grep blob | sort -k3nr | head | while read s x b x; do git rev-list --all --objects | grep $s | awk '{print "'"$b"'",$0;}'; done
    qdrizh · 2014-06-25 07:37:24 6
  • Print the IP address and the Mac address in the same line

    Print the IP address and the Mac address in the same line Show Sample Output


    1
    ifconfig | head -n 2 | tr -d '\n' | sed -n 's/.*\(00:[^ ]*\).*\(adr:[^ ]*\).*/mac:\1 - \2/p'
    Koobiac · 2014-09-03 14:35:27 18
  • Top 30 History

    Top 30 History Command line with histogram display Show Sample Output


    1
    history|awk '{print $2}'|sort|uniq -c|sort -rn|head -30|awk '!max{max=$1;}{r="";i=s=100*$1/max;while(i-->0)r=r"#";printf "%50s %5d %s %s",$2,$1,r,"\n";}'
    injez · 2014-09-29 12:40:43 9
  • Monitor system load and print out top offending processes

    This checks the system load every second and if it's over a certain threshold (.8 in this example), it spits out the date, system loads and top 4 processes sorted by CPU. Additionally, the \a in the first echo creates an audible bell.


    1
    while sleep 1; do if [ $(echo "$(cat /proc/loadavg | cut -d' ' -f1) > .8 " | bc) -gt 0 ]; then echo -e "\n\a"$(date)" \e[5m"$(cat /proc/loadavg)"\e[0m"; ps aux --sort=-%cpu|head -n 5; fi; done
    tyzbit · 2014-12-08 15:44:40 8
  • Find the date of the first commit in a git repository

    Finds the date of the first commit in a git repository branch Show Sample Output


    1
    git rev-list --all|tail -n1|xargs git show|grep -v diff|head -n1|cut -f1-3 -d' '
    binaryten · 2015-02-04 19:35:16 11
  • Most used commands from history (without perl)

    I copied this (let's be honest) somewhere on internet and I just made it as a function ready to be used as alias. It shows the 10 most used commands from history. This seems to be just another "most used commands from history", but hey.. this is a function!!! :D Show Sample Output


    1
    mosth() { history | awk '{CMD[$2]++;count++;}END { for (a in CMD)print CMD[a] " " CMD[a]/count*100 "% " a;}' | grep -v "./" | column -c3 -s " " -t | sort -nr | nl | head -n10; }
    nnsense · 2015-05-11 17:41:55 19
  • Printout a list of field numbers (awk index) from a CSV file with headers as first line.

    Useful to identify the field number in big CSV files with large number of fields. The index is the reference to use in processing with commands like 'cut' or 'awk' involved. Show Sample Output


    1
    head -1 file.csv | tr ',' '\n' | tr -d " " | awk '{print NR,$0}'
    neomefistox · 2015-08-26 05:46:15 18
  • Grab the top 5 CLFUContest one-liners


    1
    curl -sL http://goo.gl/3sA3iW | head -16 | tail -14
    cadejscroggins · 2015-09-19 07:19:49 10
  • Get AWS temporary credentials ready to export based on a MFA virtual appliance

    You might want to secure your AWS operations requiring to use a MFA token. But then to use API or tools, you need to pass credentials generated with a MFA token. This commands asks you for the MFA code and retrieves these credentials using AWS Cli. To print the exports, you can use: `awk '{ print "export AWS_ACCESS_KEY_ID=\"" $1 "\"\n" "export AWS_SECRET_ACCESS_KEY=\"" $2 "\"\n" "export AWS_SESSION_TOKEN=\"" $3 "\"" }'` You must adapt the command line to include: * $MFA_IDis ARN of the virtual MFA or serial number of the physical one * TTL for the credentials Show Sample Output


    1
    head -n1 | xargs -I {} aws sts get-session-token --serial-number $MFA_ID --duration-seconds 900 --token-code {} --output text --query [Credentials.AccessKeyId,Credentials.SecretAccessKey,Credentials.SessionToken]
    keymon · 2016-04-12 10:57:00 49
  • Find top 10 largest files


    1
    du -a /var | sort -n -r | head -n 10
    zluyuer · 2016-05-27 04:05:08 12
  • Read random news on the internet

    sort -R randomize the list. head -n1 takes the first.


    1
    links `lynx -dump -listonly "http://news.google.com" | grep -Eo "(http|https)://[a-zA-Z0-9./?=_-]*" | grep -v "google.com" | sort -R | uniq | head -n1`
    mogoh · 2016-07-26 12:54:53 15
  • Find last 50 modified files


    1
    find / -path /proc -prune -o -type f -printf '%TY-%Tm-%Td %TT %p\n' | sort -r | head -50
    sidneycrestani · 2016-11-20 02:45:01 13
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Mount windows share to the specified location including credentials
Replace IP address with yours IP.

Remove multiple spaces
The command removes all the spaces whithin a file and leaves only one space.

A simple way to securely use passwords on the command line or in scripts
In this example, where the users gpg keyring has a password, the user will be interactively prompted for the keyring password. If the keyring has no password, same as above, sans the prompt. Suitable for cron jobs. ~/.gnupg/passwd/http-auth.gpg is the encrypted http auth password, for this particular wget use case. This approach has many use cases. example bash functions: function http_auth_pass() { gpg2 --decrypt ~/.gnupg/passwd/http-auth.gpg 2>/dev/null; } function decrypt_pass() { gpg2 --decrypt ~/.gnupg/passwd/"$1" 2>/dev/null; }

Install pip with Proxy
Installs pip packages defining a proxy

command shell generate random strong password
shell generate random strong password

Display any tcp connections to apache
Sometimes apache will get stuck in an established state where you can't get a list of the connecting IP's from mod_status... not a good thing when you need to ban an abusive ip.

Block all IP addresses and domains that have attempted brute force SSH login to computer
Searches all log files (including archived bzip2 files) for invalid user and PAM authentication errors, both of which are indicative of brute force attempts at logging into computer. A list of all unique IP addresses and domain names is appended to hosts.deny. The command (and grep error messages) will work on Mac OS X 10.6, small adjustments may be needed for other OSs.

ignore .DS_Store forever in GIT
With a couple of little commands, you?ll be able to ignore the .DS_Store files forever from your git repositories on mac! The following command will add the .gitignore file to the git configuration git config --global core.excludesfile ~/.gitignore then, the following, will add the .DS_Store to the list echo .DS_Store >> ~/.gitignore

To create files with specific permission:

Updating the status on identi.ca using curl.
identica is an open source social networking and micro-blogging service. Based on Laconica, a micro-blogging software package built on the OpenMicroBlogging specification. http://identi.ca/

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