Commands by h3xx (20)

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

    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

    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. 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

    cp --sparse=always <SRC> <DST>
    h3xx · 2011-09-07 08:02:50 0
  • 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

    <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

    grep ^Dirty /proc/meminfo
    h3xx · 2011-08-24 08:48:49 7
  • 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

    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

    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:

    xargs -P 3 -n 1 <COMMAND> < <FILE_LIST>
    h3xx · 2011-07-25 22:53:32 0
  • 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].

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

    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 "$_"

    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?

    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'.

    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

    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.

    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.

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

    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.

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

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insert ip range using vim
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Alias for quick command-line volume set (works also remotely via SSH)
If you're addicted to command-line solutions of ordinary actions or if you just want to set your volume from bed via mobile phone SSH, you can set this alias and use it as $ setvol 50 for setting volume on 50% gain Works only with ALSA, tested on Ubuntu 8.10. Give me some info about your experience. TIP: Try aslo command "mute" to toggle mute/unmute sound. But I don't know if this works on all distros.

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Convert all jpegs in the current directory into ~1024*768 pixels and ~ 150 KBytes jpegs

Display current time in requested time zones.
The time zone names come from the tz database which is usually found at /usr/share/zoneinfo.

Install pip with Proxy
Installs pip packages defining a proxy

alias for psql command line; works similar for Oracles sqlplus commandline interface. if you do not provide stdin you will end up in the db shell.

Start an X app remotely
Launch a gui app remotely. In this example smplayer is installed on the remote machine, and movie.avi is in the remote user's home dir. Note that stdout/stderr is still local, so you'll have feedback locally, add '&>/dev/null' to suppress. This is surprisingly not well known (compared to running an X app locally via ssh -X). (NB. if your distro requires ~/.Xauthority file present, then try -fX if you have problems) Resubmitted (and trimmed, thanks sitaram) due to ridiculous voting on previous submission. Fingers crossed, it gets a better rating this time.

Daily watch "question pour un champion" (French TV show)
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A nice way to show git commit history, with easy to read revision numbers instead of the default hash

Summary of disk usage, excluding other filesystems, summarised and sorted by size
This command is useful for finding out which directories below the current location use the most space. It is summarised by directory and excludes mounted filesystems. Finally it is sorted by size.

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