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


    2
    $ 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


    3
    sed -n '/START/,${/STOP/q;p}'
    mungewell · 2009-06-19 15:27:36 2
  • 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


    5
    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.


    3
    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

What's this?

commandlinefu.com is the place to record those command-line gems that you return to again and again. That way others can gain from your CLI wisdom and you from theirs too. All commands can be commented on, discussed and voted up or down.

Share Your Commands


Check These Out

Multiplication table
The multiplication table for math study

My PS1
My PS1

google tts

Dump dvd from a different machine onto this one.
You can use this to directly dump from machine A (with dvd drive) to machine B (without dvd drive) . I used this to copy dvd using my friend's machine to my netbook. Above command is to be issued on machine B. Advantages : 1) No wasting time dumping first to machine A and then copying to Machine B. 2) You dont need to use space on Machine A. In fact, this will work even when Machine A doesnt have enough hdd space to dump the DVD. Use -C ssh option on slow networks (enables compression). you can replace "dd if=/dev/dvd" with any ripping command as long as it spews the iso to stdout.

vim's pastetoggle: when you press f9 'paste' is on , press f9 again and 'paste' is off, and so forth (works in insert-mode and command-mode)

pretty print JavaScript source code
https://github.com/mishoo/UglifyJS

Convert CSV to JSON
Replace 'csv_file.csv' with your filename.

Rename files in batch

Query well known ports list
Uses the file located in /etc/services

Get My Public IP Address


Stay in the loop…

Follow the Tweets.

Every new command is wrapped in a tweet and posted to Twitter. Following the stream is a great way of staying abreast of the latest commands. For the more discerning, there are Twitter accounts for commands that get a minimum of 3 and 10 votes - that way only the great commands get tweeted.

» http://twitter.com/commandlinefu
» http://twitter.com/commandlinefu3
» http://twitter.com/commandlinefu10

Subscribe to the feeds.

Use your favourite RSS aggregator to stay in touch with the latest commands. There are feeds mirroring the 3 Twitter streams as well as for virtually every other subset (users, tags, functions,…):

Subscribe to the feed for: