Commands by mhs (29)

  • Monitor all DNS queries made by Firefox


    2
    NSPR_LOG_MODULES=nsHostResolver:5 NSPR_LOG_FILE=/tmp/log.txt firefox
    mhs · 2015-09-30 01:56:36 10
  • Monitor all DNS queries seen by the local machine


    1
    dnstop -l 3 enp1s0f0
    mhs · 2015-09-30 01:55:11 9
  • Convert SWF to video

    This will dump a raw BGRA pixel stream and WAV which must then be converted to video: ffmpeg -f rawvideo -c:v rawvideo -s 1280x720 -r 12 -pix_fmt bgra -i "${i%.*}".bgra -c:v libx264 -preset veryslow -qp 0 -movflags +faststart -i "${i%.*}".wav -c:a libfdk_aac -b:a 384k "${i%.*}".mp4 ; rm "${i%.*}".bgra "${i%.*}".wav Our example generates an x264/720p/12fps/AAC best-quality MP4. To get dump-gnash, first install the build-dependencies for gnash (this step is OS-specific). Then: git clone http://git.savannah.gnu.org/r/gnash.git ; cd gnash ; ./autogen.sh ; ./configure --enable-renderer=agg --enable-gui=dump --disable-menus --enable-media=ffmpeg --disable-jemalloc ; make


    0
    i=in.swf; dump-gnash -1 -j 1280 -k 720 -D "${i%.*}".bgra@12 -A "${i%.*}".wav "${i}"
    mhs · 2015-05-06 23:52:39 27
  • Find which fibre HBA a disk is connected to

    Useful for big systems with lots of cards. (Update: does not work with USB disks)


    0
    udevadm info -q all -n /dev/sdc | grep ID_PATH | cut -d'-' -f 2 | xargs -n 1 lspci -s
    mhs · 2015-01-27 15:34:02 9
  • Generate map of your hardware


    2
    lstopo -p -v --whole-system --whole-io output.svg
    mhs · 2015-01-27 15:16:54 9
  • Map the slot of an I/O card to its PCI bus address

    Recent hardware may or may not enumerate *both of* these values


    1
    dmidecode --type 9 |egrep 'Bus Address|Designation'
    mhs · 2015-01-27 15:13:59 8
  • Aptitude pattern match

    Could be dangerous, if you have many packages all beginning with 'foo' or 'bar'. This will easily remove them all from your system.


    1
    aptitude --purge remove ~i^foo ~i^bar
    mhs · 2015-01-27 15:00:48 12
  • Nice beep


    1
    xset b 50 1700 10
    mhs · 2015-01-27 14:38:58 8
  • Performance tip: compress /usr/

    Periodically run the one-liner above if/when there are significant changes to the files in /usr/ = Before rebooting, add following to /etc/fstab : = /squashed/usr/usr.sfs /squashed/usr/ro squashfs loop,ro 0 0 usr /usr aufs udba=reval,br:/squashed/usr/rw:/squashed/usr/ro 0 0 No need to delete original /usr/ ! (unless you don't care about recovery). Also AuFS does not work with XFS


    4
    [ ! -d /squashed/usr ] && mkdir -p /squashed/usr/{ro,rw} ; mksquashfs /usr /squashed/usr/usr.sfs.new -b 65536 ; mv /squashed/usr/usr.sfs.new /squashed/usr/usr.sfs ; reboot
    mhs · 2014-05-10 06:01:06 9
  • Increase SCT of external USB disk enclosure to one hour.

    So I had this 2TB Seagate external disk/USB enclosure which by default would spin-down its internal drive (it enters a standby mode) after four minutes of inactivity.. Spinning-up the inactive drive was an annoying delay when accessing files and also it severely interfered with NFS.. SCT stands for "Standby Condition Timer". To completely disable SCT: sdparm --clear STANDBY -6 /dev/sdb To return to original (default) SCT settings: sdparm -D -p 0x1a -6 /dev/sdb To verify the settings (before and after): sdparm -a /dev/sdb No need for vendor-provided MSWIN tools, etc.


    2
    sdparm -s SCT=36000 --save /dev/sdb
    mhs · 2013-04-19 13:26:18 5
  • Limit the cpu usage of a process

    Similar to `cpulimit`, although `prlimit` can be found shipped with recent util-linux. Example: limit CPU consumption to 10% for a math problem which ordinarily takes up 100% CPU: Before: bc -l <(echo "1234123412341234^12341234") See the difference `prlimit` makes: prlimit --cpu=10 bc -l <(echo "1234123412341234^12341234") To actually monitor the CPU usage, use `top`, `sar`, etc.. or: pidstat -C 'bc' -hur -p ALL 1


    4
    prlimit --cpu=10 sort -u hugefile
    mhs · 2013-02-27 15:59:11 7
  • Commandline document conversion with Libreoffice

    In this example, the docx gets converted to Open Document .odt format. For other formats, you'll need to specify the correct filter (Hint: see "Comments" link below for a nice list).


    15
    soffice --headless -convert-to odt:"writer8" somefile.docx
    mhs · 2012-12-27 15:08:38 29
  • Android PNG screenshot

    Works with *rooted* Android devices. 400x800 are the screen dimensions of a typical handheld smartphone.


    8
    adb pull /dev/graphics/fb0 /dev/stdout | ffmpeg -vframes 1 -vcodec rawvideo -f rawvideo -pix_fmt rgb32 -s 480x800 -i pipe:0 -f image2 -vcodec png screenshot.png
    mhs · 2012-12-26 13:21:18 20
  • Dump android contacts, sms

    Crude, but works. Note for security, /data/ will be inaccessible unless your device has been *rooted*. On the other hand, if a device has been rooted, its data is now wide open to anyone with a USB cable and the above "one-liner". `adb` is one of the platform tools in the android SDK. To get SMS messages: adb pull /data/data/com.android.providers.telephony/databases/mmssms.db ; sqlite3 -batch <<EOF contacts2.db <CR> .header on <CR> .mode tabs <CR> select * from sms; <CR> EOF


    2
    adb pull /data/data/com.android.providers.contacts/databases/contacts2.db ; sqlite3 -batch <<EOF contacts2.db <CR> .header on <CR> .mode tabs <CR> select * from data; <CR> EOF
    mhs · 2012-12-26 11:35:23 21
  • wget multiple files (or mirror) from NTLM-protected Sharepoint

    If you have to deal with MS Sharepoint which is (rarely, let's hope) used in e.g. certain corporate environments). This uses Cntlm. For single files, just use cURL -- its NTLM authentication works quite well. # /etc/cntlm.conf: # Username account # Domain domain # Password ############ # Proxy 10.20.30.40 (IP of the sharepoint site) # NoProxy * # Listen 3128


    1
    http_proxy=http://127.0.0.1:3128 wget --http-user='domain\account' --http-password='###' -p -r -l 8 --no-remove-listing -P . 'http://sp.corp.com/teams/Team/Shared%20Documents/Forms/AllItems.aspx?RootFolder=%2fteams%2fTeam%2fShared%20Documents%2fFolder'
    mhs · 2012-12-26 09:03:55 4
  • Serial console to a Vmware VM

    Create a serial console with "socket (named pipe)" of "/tmp/socket", "from:server, to:virtual machine" in vmware player, etc.. gui. Run the above command after you have booted the guest OS (which should also be configured for serial console).


    1
    socat unix-connect:/tmp/socket stdio,echo=0,raw
    mhs · 2012-12-19 07:58:09 8
  • parted - scripted partitioning (of all multipathed SAN LUNs)

    `multipath -ll` requires Device Mapper multipath.conf configuration. And of course, replace "3PARdata,VV" with your disk array's SCSI vendor,LUN name. - GPT partition table allows you to create >2TB partitions


    1
    for i in $(multipath -ll | grep "3PARdata,VV"|awk '{print $1}') ; do parted -a optimal /dev/mapper/$i --script -- mklabel gpt mkpart primary 1 -1 set 1 lvm on ; done
    mhs · 2012-09-12 15:30:36 7
  • Formatted list - WWNs of all LUNs

    Use `scsi_id` to positively identify which LUNs are which (i.e. compare with the list of LUNs you created on your disk array) (shown: RHEL5 usage) Debian usage: # for i in /dev/sd* ; do wwn=`/lib/udev/scsi_id -g --device $i` ; [ "$wwn" != "" ] && echo -e ${i##*/}'\t'$wwn ;done Show Sample Output


    1
    for i in /sys/block/sd* ; do wwn=`/lib/udev/scsi_id -g -s /block/${i##*/}` ; [ "$wwn" != "" ] && echo -e ${i##*/}'\t'$wwn ;done
    mhs · 2012-09-12 14:14:53 4
  • detect partitions

    `blkid` is an interface to libuuid - it can read Device Mapper, EVMS, LVM, MD, and regular block devices. -c /dev/null - Do not use cached output from /etc/blkid.tab or /etc/blkid/blkid.tab (RHEL) -i - Display I/O Limits (aka I/O topology) information (not available in RHEL) -p - Low-level superblock probing mode (not available in RHEL) Show Sample Output


    2
    blkid -c /dev/null
    mhs · 2012-09-12 13:34:41 7
  • 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.


    8
    lsof -n -P|grep FlashXX|awk '{ print "/proc/" $2 "/fd/" substr($4, 1, length($4)-1) }'|while read f;do newname=$(exiftool -FileModifyDate -FileType -t -d %Y%m%d%H%M%S $f|cut -f2|tr '\n' '.'|sed 's/\.$//');echo "$f -> $newname";cp $f ~/Vids/$newname;done
    mhs · 2012-02-25 01:49:45 5
  • Hide the name of a process listed in the `ps` output

    exec -a $NAME $COMMAND $ARGS `your_cmd -erase_all_files` is the real process, but harmless-looking getty appears in the process table. Never actually had a need to do this, but interesting nonetheless... Tested in bash, dash. -a $NAME "pass NAME as the zeroth argument to COMMAND", i.e. customise the name of the process (as commonly seen with `ps`) Show Sample Output


    16
    exec -a "/sbin/getty 38400 tty7" your_cmd -erase_all_files
    mhs · 2012-02-01 10:54:03 8
  • Show 'Hardware path'-style tree of all devices in Linux

    Show Sample Output


    6
    lshw -short
    mhs · 2011-06-28 23:32:30 8
  • Find out the starting directory of a script

    Invoked from within a shell script, this will print the directory in which the script resides. Doesn't depend on external tools, /proc/self/*, etc.. (`echo` is a shell builtin.) To see the *current working* directory of a script, use `pwd`.


    13
    echo "${0%/*}"
    mhs · 2011-04-17 12:09:56 12
  • move messages directly from one IMAP inbox to another

    This one-liner was useful in helping someone I know to get off of MS Exchange. `mailutil` proved to be a much better alternative than `fetchmail` or `getmail` in this case. It quickly moved all mails to the destination server (a simple Dovecot/Maildir setup), with no need to convert back and forth between mbox/maildir on the user's own system.


    2
    mailutil appenddelete '{src.mailsrv1.com:993/imap/norsh/notls/ssl/novalidate-cert/user="username"}INBOX' '{dest.mailsrv2.com:143/imap/norsh/notls/user="username"}INBOX'
    mhs · 2011-02-08 09:37:05 3
  • Stop Flash from tracking everything you do.

    Brute force way to block all LSO cookies on a Linux system with the non-free Flash browser plugin. Works just fine for my needs. Enjoy. Show Sample Output


    18
    for i in ~/.adobe ~/.macromedia ; do ( rm $i/ -rf ; ln -s /dev/null $i ) ; done
    mhs · 2010-12-29 13:23:48 13
  •  1 2 > 

What's this?

commandlinefu.com is the place to record those command-line gems that you return to again and again. That way others can gain from your CLI wisdom and you from theirs too. All commands can be commented on, discussed and voted up or down.

Share Your Commands

Check These Out

Convert clipboard HTML content to markdown (for github, trello, etc)
I always wanted to be able to copy formatted HTML, like from emails, on trello cards or READMEs... but the formatting is always wrong... But from this two links: * https://jeremywsherman.com/blog/2012/02/08/pasting-html-into-markdown/ * http://stackoverflow.com/questions/3261379/getting-html-source-or-rich-text-from-the-x-clipboard For instance, to to copy an formatted email to a trello card, just: 1. Select the email body 2. run: xclip -selection clipboard -o -t text/html | pandoc -f html -t markdown_github - | xclip -i -t text/plain 3. Paste in your trello card 4. Profit! 8-)

Create a git alias that will pull and fast-forward the current branch if there are no conflicts
This command will first add an alias known only to git, which will allow you to pull a remote and first-forward the current branch. However, if the remote/branch and your branch have diverged, it will stop before actually trying to merge the two, so you can back out the changes. http://www.kernel.org/pub/software/scm/git/docs/git-pull.html Tested on git 1.5.6.1, msysgit (Windows port) Actually this is not really the way I want it. I want it to attempt a fast-foward, but not attempt to merge or change my working copy. Unfortunately git pull doesn't have that functionality (yet?).

Unbelievable Shell Colors, Shading, Backgrounds, Effects for Non-X
I've been using linux for almost a decade and only recently discovered that most terminals like putty, xterm, xfree86, vt100, etc., support hundreds of shades of colors, backgrounds and text/terminal effects. This simply prints out a ton of them, the output is pretty amazing. If you use non-x terminals all the time like I do, it can really be helpful to know how to tweak colors and terminal capabilities. Like: $ echo $'\33[H\33[2J'

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

list files recursively by size

rsync over ssh via non-default ssh port
tested on cygwin and Fedora 9 . good to remember for those jobs where you cannot set a site-specific connect option in your ~/.ssh/config file.

Show Shared Library Mappings
shows which shared lib files are pointed to by the dynamic linker.

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 compatible with BSD/IPSO

Detect illegal access to kernel space, potentially useful for Meltdown detection
Based on capsule8 agent examples, not rigorously tested

Stay in the loop…

Follow the Tweets.

Every new command is wrapped in a tweet and posted to Twitter. Following the stream is a great way of staying abreast of the latest commands. For the more discerning, there are Twitter accounts for commands that get a minimum of 3 and 10 votes - that way only the great commands get tweeted.

» http://twitter.com/commandlinefu
» http://twitter.com/commandlinefu3
» http://twitter.com/commandlinefu10

Subscribe to the feeds.

Use your favourite RSS aggregator to stay in touch with the latest commands. There are feeds mirroring the 3 Twitter streams as well as for virtually every other subset (users, tags, functions,…):

Subscribe to the feed for: