userland-book/miscellany/index.md

9. a miscellany of tools and techniques =======================================

dict

Want to know the definition of a word, or find useful synonyms?

$ dict concatenate | head -10
4 definitions found

From The Collaborative International Dictionary of English v.0.48 [gcide]:

  Concatenate \Con*cat"e*nate\ (k[o^]n*k[a^]t"[-e]*n[=a]t), v. t.
     [imp. & p. p. {Concatenated}; p. pr. & vb. n.
     {Concatenating}.] [L. concatenatus, p. p. of concatenare to
     concatenate. See {Catenate}.]
     To link together; to unite in a series or chain, as things
     depending on one another.

aspell

Need to interactively spell-check your presentation notes?

$ aspell check presentation

Just want a list of potentially-misspelled words in a given file?

$ aspell list < ../literary_environment/index.md | sort | uniq -ci | sort -nr | head -5
     40 td
     24 Veselka
     17 Reuel
     16 Brunner
     15 Tiptree

mostcommon

Something like that last sequence sure does seem to show up a lot in my work: Spit out the n most common lines in the input, one way or another. Here's a little script to be less repetitive about it.

$ aspell list < ../literary_environment/index.md | ./mostcommon -i -n5
     40 td
     24 Veselka
     17 Reuel
     16 Brunner
     15 Tiptree

This turns out to be pretty simple:

$ cat ./mostcommon
#!/usr/bin/env bash

# Optionally specify number of lines to show, defaulting to 10:
TOSHOW=10
CASEOPT=""

while getopts ":in:" opt; do
  case $opt in
    i)
      CASEOPT="-i"
      ;;
    n)
      TOSHOW=$OPTARG
      ;;
    \?)
      echo "Invalid option: -$OPTARG" >&2
      exit 1
      ;;
    :)
      echo "Option -$OPTARG requires an argument." >&2
      exit 1
      ;;
  esac
done

# sort and then uniqify STDIN,
# sort numerically on the first field,
# chop off everything but $TOSHOW lines of input

sort < /dev/stdin | uniq -c $CASEOPT | sort -k1 -nr | head -$TOSHOW

Notice, though, that it doesn't handle opening files directly. If you wanted to find the most common lines in a file with it, you'd have to say something like mostcommon < filename in order to redirect the file to mostcommon's input.

Also notice that most of the script is boilerplate for handling a couple of options. The work is all done in a oneliner. Worth it? Maybe not, but an interesting exercise.

cal and ncal

Want to know what the calendar looks like for this month?

$ cal
     April 2014       
Su Mo Tu We Th Fr Sa  
       1  2  3  4  5  
 6  7  8  9 10 11 12  
13 14 15 16 17 18 19  
20 21 22 23 24 25 26  
27 28 29 30           

How about for September, 1950, in a more compact format?

$ ncal -m9 1950
    September 1950    
Su     3 10 17 24   
Mo     4 11 18 25   
Tu     5 12 19 26   
We     6 13 20 27   
Th     7 14 21 28   
Fr  1  8 15 22 29   
Sa  2  9 16 23 30   

Need to know the date of Easter this year?

$ ncal -e
April 20 2014

seq

Need the numbers 1-5?

$ seq 1 5
1
2
3
4
5

shuf

Want to shuffle some lines?

$ seq 1 5 | shuf
2
1
4
3
5

ptx

Want to make a [permuted index][kwic] of some phrase?

$ echo 'i like american music' | ptx
                              i like   american music
                                       i like american music
                                   i   like american music
                     i like american   music

figlet

Need to make ASCII art of some giant letters?

$ figlet "R T F M"
 ____    _____   _____   __  __ 
|  _ \  |_   _| |  ___| |  \/  |
| |_) |   | |   | |_    | |\/| |
|  _ <    | |   |  _|   | |  | |
|_| \_\   |_|   |_|     |_|  |_|

cowsay

How about ASCII art of a cow dragon saying something?

$ cowsay -f dragon "RTFM, man"
 ___________
< RTFM, man >
 -----------
      \                    / \  //\
       \    |\___/|      /   \//  \\
            /0  0  \__  /    //  | \ \    
           /     /  \/_/    //   |  \  \  
           @_^_@'/   \/_   //    |   \   \ 
           //_^_/     \/_ //     |    \    \
        ( //) |        \///      |     \     \
      ( / /) _|_ /   )  //       |      \     _\
    ( // /) '/,_ _ _/  ( ; -.    |    _ _\.-~        .-~~~^-.
  (( / / )) ,-{        _      `-.|.-~-.           .~         `.
 (( // / ))  '/\      /                 ~-. _ .-~      .-~^-.  \
 (( /// ))      `.   {            }                   /      \  \
  (( / ))     .----~-.\        \-'                 .~         \  `. \^-.
             ///.----..>        \             _ -~             `.  ^-`  ^-_
               ///-._ _ _ _ _ _ _}^ - - - - ~                     ~-- ,.-~
                                                                  /.-~