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 81
  • 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 45
  • 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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back ssh from firewalled hosts
host B (you) redirects a modem port (62220) to his local ssh. host A is a remote machine (the ones that issues the ssh cmd). once connected port 5497 is in listening mode on host B. host B just do a ssh 127.0.0.1 -p 5497 -l user and reaches the remote host'ssh. This can be used also for vnc and so on.

list block devices
Shows all block devices in a tree with descruptions of what they are.

Find out what package some command belongs to (on RPM systems)
Replace 'more' command with any command which is in your PATH.

list files recursively by size

Monitor memory usage
Monitor with watch command and vmstat, memory usage

Search for a single file and go to it
This command looks for a single file named emails.txt which is located somewhere in my home directory and cd to that directory. This command is especially helpful when the file is burried deep in the directory structure. I tested it against the bash shells in Xubuntu 8.10 and Mac OS X Leopard 10.5.6

Speed up launch of liferea
If you use liferea frequently, you will see obvious speedup after you executed this command.

Edit a PDF's metadata using exiftool
Edit the pdf file foo.pdf's metadata. -overwrite_original overwrites the original file (w/o it exiftool creates a new file)

Edit 2 or more files in vim using vim -d
Use vim's diff mode to edit two or more files in one window. The '+diffoff!' turns off diff highlighting when the session is started. Use ctrl+w + ctrl+w to switch between windows.

geoip lookup

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