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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tail -f a log file over ssh into growl

dump database from postgresql to a file

Lists all usernames in alphabetical order

Keep a copy of the raw Youtube FLV,MP4,etc stored in /tmp/
Certain Flash video players (e.g. Youtube) write their video streams to disk in /tmp/ , but the files are unlinked. i.e. the player creates the file and then immediately deletes the filename (unlinking files in this way makes it hard to find them, and/or ensures their cleanup if the browser or plugin should crash etc.) But as long as the flash plugin's process runs, a file descriptor remains in its /proc/ hierarchy, from which we (and the player) still have access to the file. The method above worked nicely for me when I had 50 tabs open with Youtube videos and didn't want to have to re-download them all with some tool.

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" }

Change the homepage of Firefox
Pros: Works in all Windows computers, most updated and compatible command. Cons: 3 liner Replace fcisolutions.com with your site name.

Copy without overwriting

Fast, built-in pipe-based data sink
This is shorter and actually much faster than >/dev/null (see sample output for timings) Plus, it looks like a disappointed face emoticon.

bash screensaver off

return the latest kernel version from a Satellite / Spacewalk server software channel


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