Commands by lucasrangit (9)


  • 2
    gcc -dM -E - < /dev/null
    lucasrangit · 2012-04-27 17:37:50 0
  • When you SSH to a server who's hostname or IP has changed since the last time a connection was recorded in the known_hosts file a warning will be displayed since this indicated a possible DNS spoofing attack. If this is a known change then this command will remove the previous entry and allow the SSH connection. The SSH client will prompt you as if it was the first time connected to the server. Replace ${LINE} with the line of the offending key in ~known_hosts. 49 in the sample output. Show Sample Output


    -5
    sed -i '${LINE}d' ~/.ssh/known_host
    lucasrangit · 2012-01-16 18:00:12 3
  • I often find it useful to know what the exit status for a program was. This can be helpful when looking up errors by exit status or when scripting frequent commands. Taken from http://www.faqs.org/docs/abs/HTML/exit-status.html Show Sample Output


    -1
    echo $?
    lucasrangit · 2011-07-27 15:34:20 0
  • This avoids the "chmod +x filename" after performing a check out or export. From http://snipplr.com/view/5277/set-executable-permissions-on-a-file-under-subversion/ Show Sample Output


    2
    svn propset svn:executable ON filename
    lucasrangit · 2011-07-18 22:51:43 0
  • This will extract all DCT format images from foo.pdf and save them in JPEG format (option -j) to bar-000.jpg, bar-001.jpg, bar-002.jpg, etc. Inspired by http://stefaanlippens.net/extract-images-from-pdf-documents


    3
    pdfimages -j foo.pdf bar
    lucasrangit · 2011-07-07 17:18:36 0
  • Booting the VM headless via VBoxHeadless requires knowledge of the VM's network in order to connect. Using VBoxManage in this way and you can SSH to the VM without first looking up the current IP, which changes depending on how you have your VM configured. Show Sample Output


    9
    ssh vm-user@`VBoxManage guestproperty get "vm-name" "/VirtualBox/GuestInfo/Net/0/V4/IP" | awk '{ print $2 }'`
    lucasrangit · 2011-05-04 18:01:36 0

  • 4
    abiword --to=html file.doc --exp-props=
    lucasrangit · 2011-01-05 19:31:25 0
  • I often find the need to number enumerations and other lists when programming. With this command, create a new file called 'inputfile' with the text you want to number. Paste the contents of 'outputfile' back into your source file and fix the tabbing if necessary. You can also change this to output hex numbering by changing the "%02d" to "%02x". If you need to start at 0 replace "NR" with "NR-1". I adapted this from http://osxdaily.com/2010/05/20/easily-add-line-numbers-to-a-text-file/. Show Sample Output


    1
    awk '{printf("/* %02d */ %s\n", NR,$0)}' inputfile > outputfile
    lucasrangit · 2011-01-04 19:13:55 0
  • Find C/C++ source files and headers in the current directory. Show Sample Output


    2
    find . -name '*.[c|h]pp' -o -name '*.[ch]' -type f
    lucasrangit · 2010-03-11 01:22:06 2

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Check These Out

Extract public key from private
This will extract the public key that is stored in the private key using openssl.

rsync + find
use find with rsync

gets all files committed to svn by a particular user since a particular date
just change the date following the -r flag, and/or the user name in the user== conditional statement, and substitute yms_web with the name of your module

Block all IP addresses and domains that have attempted brute force SSH login to computer
I use iptables. To rate limit connections. Very easy and no ban lists to manage.

Run the last command as root
Same as `sudo !!`. If you do not have permission to be sudo or sudo does not installed on your system, you can use this.

Monitor all DNS queries seen by the local machine

Use bash history with process substitution
Bash has a great history system of its commands accessed by the ! built-in history expansion operator (documented elsewhere on this site or on the web). You can combine the ! operator inside the process redirection

Convert seconds to [DD:][HH:]MM:SS
Converts any number of seconds into days, hours, minutes and seconds. sec2dhms() { declare -i SS="$1" D=$(( SS / 86400 )) H=$(( SS % 86400 / 3600 )) M=$(( SS % 3600 / 60 )) S=$(( SS % 60 )) [ "$D" -gt 0 ] && echo -n "${D}:" [ "$H" -gt 0 ] && printf "%02g:" "$H" printf "%02g:%02g\n" "$M" "$S" }

Given process ID print its environment variables
Same as previous but without fugly sed =x

List all active access_logs for currently running Apache or Lighttpd process
Ever logged into a *nix box and needed to know which webserver is running and where all the current access_log files are? Run this one liner to find out. Works for Apache or Lighttpd as long as CustomLog name is somewhat standard. HINT: works great as input into for loop, like this: $ for i in `lsof -p $(netstat -ltpn|awk '$4 ~ /:80$/ {print substr($7,1,index($7,"/")-1)}')| awk '$9 ~ /access.log$/ {print $9| "sort -u"}'` ; do echo $i; done Very useful for triage on unfamiliar servers!


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