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Commands by mhs from sorted by
Terminal - Commands by mhs - 21 results
[ ! -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
2014-05-10 06:01:06
User: mhs
Functions: mkdir mv
Tags: performance ssd squashfs
4
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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

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sdparm -s SCT=36000 --save /dev/sdb
2013-04-19 13:26:18
User: mhs
Tags: sdparm
2
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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.

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prlimit --cpu=10 sort -u hugefile
2013-02-27 15:59:11
User: mhs
Functions: sort
Tags: cpu util-linux
4
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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
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soffice --headless -convert-to odt:"writer8" somefile.docx
2012-12-27 15:08:38
User: mhs
Tags: convert libreoffice soffice
14
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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).

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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
2012-12-26 13:21:18
User: mhs
Tags: screenshot adb android
8
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Android PNG screenshot

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

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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
2012-12-26 11:35:23
User: mhs
Functions: tabs
Tags: contacts adb android sms sqlite3
2
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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
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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'
2012-12-26 09:03:55
User: mhs
Functions: wget
Tags: wget sharepoint cntlm
1
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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

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socat unix-connect:/tmp/socket stdio,echo=0,raw
2012-12-19 07:58:09
User: mhs
Tags: serial console socat vmware
1
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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).

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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
2012-09-12 15:30:36
User: mhs
Functions: awk grep set
Tags: multipath parted
1
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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

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for i in /sys/block/sd* ; do wwn=`/lib/udev/scsi_id -g -s /block/${i##*/}` ; [ "$wwn" != "" ] && echo -e ${i##*/}'\t'$wwn ;done
2012-09-12 14:14:53
User: mhs
Functions: echo
Tags: sysfs WWN LUNs scsi_id
1
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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
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blkid -c /dev/null
2012-09-12 13:34:41
User: mhs
Tags: partition uuid sysfs blkid util-linux
2
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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)

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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
2012-02-25 01:49:45
User: mhs
Functions: awk cp cut echo grep read sed tr
Tags: youtube flash flv exiftool tmpfs
8
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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.

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exec -a "/sbin/getty 38400 tty7" your_cmd -erase_all_files
2012-02-01 10:54:03
User: mhs
Functions: exec
Tags: exec ps process table
16
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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`)

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lshw -short
2011-06-28 23:32:30
User: mhs
Tags: lshw ioscan
6
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Show 'Hardware path'-style tree of all devices in Linux
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echo "${0%/*}"
2011-04-17 12:09:56
User: mhs
Functions: echo
Tags: Process Management parameter expansion special parameters
11
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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`.

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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'
2011-02-08 09:37:05
User: mhs
Tags: mailutil IMAP
2
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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.

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for i in ~/.adobe ~/.macromedia ; do ( rm $i/ -rf ; ln -s /dev/null $i ) ; done
2010-12-29 13:23:48
User: mhs
Functions: ln rm
Tags: flash LSO cookies
18
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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.

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xfreerdp --plugin rdpsnd -g 1280x720 -a 24 -z -x m -u $username -p $password 10.20.30.40
2010-12-29 11:21:18
User: mhs
Tags: rdesktop RDP
2
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Open Remote Desktop (RDP) from command line having a custom screen size

This example uses xfreerdp, which builds upon the development of rdesktop. This example usage will also send you the remote machine's sound.

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perl -wlne'/title>([^<]+)/i&&rename$ARGV,"$1.html"' *.html
2010-12-29 05:39:41
User: mhs
Functions: perl
Tags: rename
9
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Rename HTML files according to their title tag

The above one-liner could be run against all HTML files in a directory. It renames the HTML files based on the text contained in their title tag. This helped me in a situation where I had a directory containing thousands of HTML documents with meaningless filenames.

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infocmp rxvt-unicode | ssh 10.20.30.40 "mkdir -p .terminfo && cat >/tmp/ti && tic /tmp/ti"
2010-12-29 00:44:49
User: mhs
Functions: ssh
Tags: terminfo
3
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Send your terminfo to another machine

I frequently use this trick to send my terminal settings to HPUX and older RHEL systems. This is due to the fact that terminfo support for rxvt-unicode (my preferred terminal app) does not exist on many older Linux and Unices.

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file -s /dev/sd*
2010-12-28 09:56:03
User: mhs
Functions: file
Tags: file devfs
24
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Use file(1) to view device information

file(1) can print details about certain devices in the /dev/ directory (block devices in this example). This helped me to know at a glance the location and revision of my bootloader, UUIDs, filesystem status, which partitions were primaries / logicals, etc.. without running several commands.

See also:

file -s /dev/dm-* file -s /dev/cciss/*

etc..

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