Commands by lucasrangit (9)


  • 2
    gcc -dM -E - < /dev/null
    lucasrangit · 2012-04-27 17:37:50 3
  • 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 6
  • 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 3
  • 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 3
  • 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 9
  • 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 6

  • 4
    abiword --to=html file.doc --exp-props=
    lucasrangit · 2011-01-05 19:31:25 7
  • 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 24
  • 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 16

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Serve current directory tree at http://$HOSTNAME:8080/

Quickly CD Out Of Directories Without 5+ Aliases
I wrote this a long time ago, wondering why this wasn't floating around somewhere out there (at least not where I could find).. this seems much more simple than multiple aliases and can cd out of directories easier.

determine if tcp port is open

Get the list of local files that changed since their last upload in an S3 bucket
Can be useful to granulary flush files in a CDN after they've been changed in the S3 bucket.

capture selected window
I think, this is a shorter one :)

Get all files of particular type (say, PDF) listed on some wegpage (say, example.com)
See man wget if you want linked files and not only those hosted on the website.

Visit wikileaks.com
Who needs a DNS server

To print a specific line from a file
You can get one specific line during any procedure. Very interesting to be used when you know what line you want.

use the real 'rm', distribution brain-damage notwithstanding
The backslash avoids any 'rm' alias that might be present and runs the 'rm' command in $PATH instead. In a misguided attempt to be more "friendly", some Linux distributions (or sites/etc.) alias 'rm' to 'rm -i'. Unfortunately, this trains users to expect that files won't actually be deleted until they okay it. This expectation will fail with catastrophic results when they use other distributions, move to other sites, etc., and doesn't really even work 100% even with the alias. It's too late to fix 'rm', but '\rm' should work everywhere (under bash).

Compare two files side-by-side
I found out about this from Unix Power Tools, and thought it was pretty useful. Use the -w option to change the width of the output, and the -s option to suppress lines that are the same in both files.


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