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


    37
    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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check the status of 'dd' in progress (OS X)
While a dd is running in one terminal, open another and enter the while loop. The sample output will be displayed in the window running the dd and the while loop will exit when the dd is complete. It's possible that a "sudo" will need to be inserted before "pkill", depending on your setup, for example: $ while pgrep ^dd; do sudo pkill -INFO dd; sleep 10; done

get the ascii number with bash builtin printf

check open ports without netstat or lsof

List all symbolic links in current directory that matches regexp
Perl alternative to list symlinks with a clumsy regexp filter: place the regex instead of he example 'libxml' and end it with a wildchar to see the results (previous cd on dir). Is it possible change the '-l' test for '-d' and it will search for directories. [Same applies for -x and -X. See $(perldoc -f -x) for more tests]. I use it quite often when dealing with shared libraries...

Find broken symlinks
Locate broken symlinks in the current directory. Also useful, to remove broken links: $ find . -type l ! -exec test -e {} \; -print0 | xargs -0 rm

Make vim open in tabs by default (save to .profile)
I always add this to my .profile rc so I can do things like: "vim *.c" and the files are opened in tabs.

Output Detailed Process Tree for any User
An easy function to get a process tree listing (very detailed) for all the processes of any gived user. This function is also in my http://www.askapache.com/linux-unix/bash_profile-functions-advanced-shell.html

Get length of current playlist in xmms2

Show apps that use internet connection at the moment.
This corrects duplicate output from the previous command.

check open ports without netstat or lsof


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