Commands by h3xx (20)

  • Real gurus don't need fancy tools like iftop or jnettop. Show Sample Output


    9
    tcpdump -w - |pv -bert >/dev/null
    h3xx · 2011-12-14 00:24:02 4
  • For when you need a quick spell check. Show Sample Output


    10
    aspell -a <<< '<WORDS>'
    h3xx · 2011-11-30 01:47:46 3
  • This causes cp to detect and omit large blocks of nulls. Sparse files are useful for implying a lot of disk space without actually having to write it all out. http://en.wikipedia.org/wiki/Sparse_file You can use it in a pipe too: dd if=/dev/zero bs=1M count=5 |cp --sparse=always /dev/stdin SPARSE_FILE Show Sample Output


    4
    cp --sparse=always <SRC> <DST>
    h3xx · 2011-09-07 08:02:50 6
  • This is shorter and actually much faster than >/dev/null (see sample output for timings) Plus, it looks like a disappointed face emoticon. Show Sample Output


    22
    <COMMAND> |:
    h3xx · 2011-08-28 23:48:29 13
  • Ever ask yourself "How much data would be lost if I pressed the reset button?" Scary, isn't it? Show Sample Output


    34
    grep ^Dirty /proc/meminfo
    h3xx · 2011-08-24 08:48:49 8
  • Tells you everything you could ever want to know about all files and subdirectories. Great for package creators. Totally secure too. On my Slackware box, this gets set upon login: LS_OPTIONS='-F -b -T 0 --color=auto' and alias ls='/bin/ls $LS_OPTIONS' which works great. Show Sample Output


    2
    lsr() { find "${@:-.}" -print0 |sort -z |xargs -0 ls $LS_OPTIONS -dla; }
    h3xx · 2011-08-15 03:10:58 0

  • 0
    echo $(($(ulimit -u)-$(pgrep -u $USER|wc -l))
    h3xx · 2011-07-30 05:03:36 0
  • These are way better than fortune(6). Show Sample Output


    2
    grep -2riP '\b(fuck|shit|bitch|tits|ass\b)' /usr/src/linux/
    h3xx · 2011-07-27 23:11:02 1
  • For instance: find . -type f -name '*.wav' -print0 |xargs -0 -P 3 -n 1 flac -V8 will encode all .wav files into FLAC in parallel. Explanation of xargs flags: -P [max-procs]: Max number of invocations to run at once. Set to 0 to run all at once [potentially dangerous re: excessive RAM usage]. -n [max-args]: Max number of arguments from the list to send to each invocation. -0: Stdin is a null-terminated list. I use xargs to build parallel-processing frameworks into my scripts like the one here: http://pastebin.com/1GvcifYa


    2
    xargs -P 3 -n 1 <COMMAND> < <FILE_LIST>
    h3xx · 2011-07-25 22:53:32 1
  • Crash Override, man! Apparently the exec call tricks BASH into setting the output buffer size to 0 under the assumption that the system (or the calling shell) will handle the output buffering. trapping the ERR signal will stop the subshell from dying and sending the ERR signal to the main script--which will terminate immediately if it does--when the program fails. The only problem is that the kernel will output a whole bunch of stack trace garbage directly to the console device once the process segfaults, so there's no way to prevent it from being output [that I know of].


    0
    (trap 'true' ERR; exec <SEGFAULT_PRONE_PROGRAM>)
    h3xx · 2011-07-25 02:30:52 0
  • Even adds a newline.


    1
    xxd -p <<< <STRING>
    h3xx · 2011-07-24 19:16:32 0

  • 0
    read VAR1 VAR2 VAR3 <<< aa bb cc; echo $VAR2
    h3xx · 2011-07-24 18:56:30 0
  • You can also save EXIF information by copying it to temp.jpg: jpegtran -optimize -outfile temp.jpg <JPEG> && jhead -te temp.jpg "$_" && mv temp.jpg "$_"


    0
    jpegtran -optimize -outfile temp.jpg <JPEG> && mv temp.jpg "$_"
    h3xx · 2011-07-24 08:55:46 0
  • Or, aumix -v -5 Map these to key combinations in your window manager and who needs special buttons?


    0
    aumix -v +5
    h3xx · 2011-07-24 07:41:40 0
  • This forces X back to its maximum resolution configured. To get a list, type `xrandr'.


    2
    xrandr -s 0
    h3xx · 2011-07-24 07:38:01 0
  • Works really well for playing DVDs, which have the volume turned way down for some reason. The `2' method is better IMHO because it will adjust to changing loud/soft parts. If you want to add it to your ~/.mplayer/config: # format: volnorm[=method:target] # method: # 1: use single sample (default) # 2: multiple samples # target: # default is 0.25 af-add=volnorm=2:0.75


    3
    mplayer -af volnorm=2:0.75 dvd://
    h3xx · 2011-07-24 07:26:51 0
  • Make sure the file contents can't be retrieved if anyone gets ahold of your physical hard drive. With hard drive partition: gpg --default-recipient-self -o /path/to/encrypted_backup.gpg -e /dev/sdb1 && shred -z /dev/sdb1 WARNING/disclaimer: Be sure you... F&%k it--just don't try this.


    0
    gpg -e --default-recipient-self <SENSITIVE_FILE> && shred -zu "$_"
    h3xx · 2011-07-24 05:51:47 0
  • Skip forward and back using the < and > keys. Display the file title with I.


    1
    mplayer -playlist <(find "$PWD" -type f)
    h3xx · 2011-07-24 03:27:03 0
  • zless /proc/config.gz


    0
    zgrep CONFIG_MAGIC_SYSRQ /proc/config.gz
    h3xx · 2011-07-24 02:06:09 0
  • This will affect all invocations of grep, even when it is called from inside a script.


    1
    export GREP_OPTIONS='--color=auto'
    h3xx · 2011-07-24 01:32:10 0

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Edit a file on a remote host using vim

Reconnect to screen without disconnecting other sessions
Have your screen session running in multiple places. (warning, things start to look weird if the terminal windows have different dimensions)

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

Find usb device in realtime
Using this command you can track a moment when usb device was attached.

Generate an XKCD #936 style 4 word password
4 random words are better than one obfuscated word http://xkcd.com/936/

find and grep Word docs
Find Word docs by filename in the current directory, convert each of them to plain text using antiword (taking care of spaces in filenames), then grep for a search term in the particular file. (Of course, it's better to save your data as plain text to make for easier grepping, but that's not always possible.) Requires antiword. Or you can modify it to use catdoc instead.

list block devices
Shows all block devices in a tree with descruptions of what they are.

Erase CD RW

HourGlass
Displays an animated hourglass for x amount of seconds

drop first column of output by piping to this


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