Commands by splante (8)

  • This is an alternative to #9131. ffmpeg didn't work on my .au files, though it did on the .wav ones. Also useful if you don't have ffmpeg but do have sox. Handily, sox already reports in seconds (decimal). Show Sample Output


    3
    get_duration() { durline=$(sox "$1" -n stat 2>&1|grep "Length (seconds):");echo ${durline#*\: }; }
    splante · 2011-09-02 15:22:43 1
  • Shorter, easier to remember version of cmd#7636 NTP is better, but there are situations where it can't be used. In those cases, you can do this to sync the local time to a server. Show Sample Output


    39
    date --set="$(ssh user@server date)"
    splante · 2011-08-30 20:03:06 3
  • This is an alternative to another command using two xargs. If it's a command you know there's only one of, you can just use: ls -l /proc/$(pgrep COMMAND)/cwd Show Sample Output


    3
    eval ls -l /proc/{$(pgrep -d, COMMAND)}/cwd
    splante · 2011-04-14 13:41:58 4
  • This is regarding the command 8263 using an alias to fill in command line options for psql. You can actually just type 'psql'. In order for that to work, you want to set environment variables PGDATABASE, PGHOST, PGUSER, and (except you're using the default) PGPORT. Also, you can add a line "host:port:dbname:user:password" (asterisk ok in some columns) to your ~/.pgpass file. Finally, if you don't like the aligned columns, you can add the line "\pset format unaligned" to your ~/.psqlrc file.


    2
    psql
    splante · 2011-04-08 18:35:20 0
  • Admittedly, I'd never have thought of this without the earlier examples, but here's one that you can execute from your workstation to just display the image from another, without separately doing a file transfer, etc. By the way, I hear a loud beep coming from the other room, so I guess it's not too stealthy :-D


    12
    ssh user@remote-host "DISPLAY=:0.0 import -window root -format png -"|display -format png -
    splante · 2011-04-08 01:07:41 1
  • The "type" builtin command is handy to find out what executable will be used if you issue a command. But on some distros, particularly when using /etc/alternatives, certain executables get buried under layers and layers of symbolic links and it becomes hard to find which one. If you put the above command in your .bashrc, it adds a "-c" option to the type command that will weed through the symbolic links and prints the actual file that will be executed. Show Sample Output


    0
    type () { if [ "$1" = "-c" ]; then shift; for f in "$@"; do ff=$(builtin type -p "$f"); readlink -f "$ff"; done; else builtin type $typeopts "$@"; fi; }
    splante · 2011-04-07 18:57:51 0
  • Credit goes to brun65i but he posted it as a comment instead as an alternative. I hadn't noticed the -h option on sort before and this seems like the cleanest alternative. Thanks Brun65i! Show Sample Output


    0
    du -h --max-depth=1 | sort -hr
    splante · 2011-04-07 18:01:18 0
  • ksh's version of cd has an optional syntax where you can type "cd old new" and it will replace "old" with "new" in your current directory and take you there. This is very handy when you have a parallel directory structure, like source and object directories. As suggested, you can just type cd ${PWD/old/new} to get this in bash, but this function in your .bashrc will let you type the ksh cd syntax and avoid typing the special characters while preserving other cd functionality. Show Sample Output


    0
    cd () { cdop=""; while [ "$1" != "${1#-}" ]; do cdop="${cdop} ${1}"; shift; done; if [ $# -eq 2 ]; then newdir="${PWD/$1/$2}"; [ -d "${newdir}" ] || { echo "no ${newdir}"; return 1; }; builtin cd $cdop "${newdir}"; else builtin cd $cdop "$@"; fi }
    splante · 2011-04-07 14:36:26 0

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Fork Bomb for Windows
Quick and dirty forkbomb for all flavors of windows Do not use in production. Replace start with a command of your choice, this will just open a new command prompt and is pretty tricky to stop once started

Sort file greater than a specified size in human readeable format including their path and typed by color, running from current directory
1. find file greater than 10 MB 2. direct it to xargs 3. xargs pass them as argument to ls

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" }

String to binary
Cool but useless.

Update zone file Serial numbers
Will edit *.db files in the same directory with todays date. Useful for doing a mass update to domains on a nameserver, adding spf records, etc. Looks for a string starting with 200 or 201 followed by 7 numbers, and replaces with todays date. This won't overwrite Ip's but i would still do some double checking after running this. Make sure your server's date is correct, otherwise insert your own serial number. $rndc reload should usually follow this command.

Grab just the title of a youtube video
There's another version on here that uses GET but some people don't have lwp-request, so here's an alternative. It's also a little shorter and should work with most youtube URLs since it truncates at the first &

a fast way to repeat output a byte
the speed is about 500MB/s on my machine. i think it's fast enough to output not too many bytes. while a C program may output 1GB per sencond on my machine. if the size is not the power of 512,you may change the bs and count in dd.

Play music from youtube without download

slow down CPU and IO for process and its offsprings.

convert filenames in current directory to lowercase
This will convert filenames from uppercase to lowercase. I find this useful after downloading images from my digital camera. This works for English, but other languages may need something slightly more complex like this: $ for i in *; do mv "$i" "$(echo $i|tr [:upper:] [:lower:])"; done Also, the quote marks aren't necessary if your filenames don't contain spaces.


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