Commands by mungewell (4)

  • converts any number on the 'stdin' to SI notation. My version limits to 3 digits of precious (working with 10% resistors). Show Sample Output

    $ awk '{ split(sprintf("%1.3e", $1), b, "e"); p = substr("yzafpnum_kMGTPEZY", (b[2]/3)+9, 1); o = sprintf("%f", b[1] * (10 ^ (b[2]%3))); gsub(/\./, p, o); print substr( gensub(/_[[:digit:]]*/, "", "g", o), 1, 4); }' < test.dat
    mungewell · 2009-07-22 16:54:14 5
  • GNU Sed can 'address' between two regex, but it continues parsing through to the end of the file. This slight alteration causes it to terminate reading the input file once the STOP match is made. In my example I have included an extra '/START/d' as my 'start' marker line contains the 'stop' string (I'm extracting data between 'resets' and using the time stamp as the 'start'). My previous coding using grep is slightly faster near the end of the file, but overall (extracting all the reset cycles in turn) the new SED method is quicker and a lot neater. Show Sample Output

    sed -n '/START/,${/STOP/q;p}'
    mungewell · 2009-06-19 15:27:36 1
  • I've been auto-generating some complex GnuPlots; with multiplots the first plot of each group needs to be a 'plot' whereas the others need to be 'replots' to allow overplotting/autoscaling/etc to work properly. This is used to replace only the first instance of 'replot'. Show Sample Output

    sed '/MARKER/{N;s/THIS/THAT/}'
    mungewell · 2009-06-12 02:29:50 0
  • Sometimes jittery data hides trends, performing a rolling average can give a clearer view.

    awk 'BEGIN{size=5} {mod=NR%size; if(NR<=size){count++}else{sum-=array[mod]};sum+=$1;array[mod]=$1;print sum/count}' file.dat
    mungewell · 2009-05-29 00:07:24 0

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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" }

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

burn initial session on a growable DVD using growisofs
replace "directory name to burn on DVD" with actual directory name that you want to copy on DVD

Generate MD5 of string and output only the hash checksum in a readable format
Generates the md5 hash, without the trailing " -" and with the output "broken" into pairs of hexs.

convert UNIX timestamp to UTC timestamp
date -ud @1320198157

Rename files in batch

See n most used commands in your bash history
You can append these commands to the bottom of the history file to access them easier with the Up key: $ sort ~/.bash_history|uniq -c|sort -n|tail -n 10|tr -s " "|cut -d' ' -f3- >> ~/.bash_history

Rename a file with a random name
Give files a random name (don't ask why :-) The function will rename files but maintain their extensions. BUG: If a file doesn't have an extension it will end up with a dot at the end of the name. The parameter '8' for pwgen controls the length of filenames - eight random characters.

Command line progress bar
This command tar?s up a directory and sends the output to gzip, showing a rate of 223MB/s. This may require you installing the pv command. For debian based users out there: $ sudo aptitude install pv

import a new set of files located in a local directory into a remote Subversion repository

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