Homebrew

Installing open source apps & libraries in Terminal

True open source stylin': a tool chest of programs which do a single thing very well that you chain together to do more advanced things.

Links:

• Homebrew website
• Homebrew Demystified: OS X's Ultimate Package Manager
• What are the first or must-have Homebrew packages that you install on your Mac?

A few packages to install & play with:

1. cowsay - try it. nuff said

   # say something
   cowsay "hello world"
   
   # think something
   cowthink "what is she wearing??!"
   
   # a wired cow
   cowsay -w "dude, finals are TOMORROW"
   
   # using a cowfile
   cowsay -f vader "Luke, I am your father."
   
   # cowsay inception
   echo "get me out of here" | cowsay -n | cowsay -nd | cowsay -np

2. cmatrix - Matrix up in your Terminal

   cmatrix

3. wget - download anything (similar to curl)

   wget http://something/you/want/on/your/computer.jpg

4. youtube-dl - download media from youtube and various other sharing sites

   # list available video formats
   youtube-dl -F https://www.youtube.com/watch?v=w6DW4i-mfbA
   
   # download medium-sized mp4 (format 18)
   youtube-dl -f 18 https://www.youtube.com/watch?v=w6DW4i-mfbA

5. imagemagick - encode/decode any image

   # resize all jpgs in the current folder to 320 wide
   mogrify -resize 320 *.jpg 
   
   # create an animated gif using all the jpgs in the current folder
   convert -delay 15 -loop 0 *.jpg douglas.gif

6. ffmpeg - encode/decode any video

   # output png frames at 5 fps
   ffmpeg -i input.mp4 -r 5 frames%04d.png

7. sox - encode/decode any audio

   # combine multiple files
   sox -m file1.wav file2.wav output.wav  
   
   # copy part of a file into another file (start & duration in seconds)
   sox input.wav output.wav trim 90 120  
   
   # reverse a file
   sox input.wav output.wav reverse
   
   # just play a file in reverse
   sox input.wav reverse
   
   # change the sample rate of a file
   sox input.wav -r 22050 output.wav
   
   # change the speed of a file (speed as a multiplier where 1.0 is normal speed)
   sox input.wav output.wav speed 3.0
   
   # extract the left channel of a stereo file into a separate file (l - left, r - right, etc)
   sox stereo.wav -c 1 mono.wav avg -l

8. lynx - text-mode web browser

   lynx class.danomatika.com

9. pandoc - convert Markdown to html, epub, pdf, etc

   # convert Markdown to a standalone HTML file
   pandoc -s README.md -o example.html

10. calc - interactive calculator

    # start calc
    calc
    
    # interest calculation: I (interest) = P (principal) * r (interest rate) * n (number of periods)
    
    # calculate the interest for 1 month of a $20k loan at 6%
    ; P = 20000
    ; r = 0.06
    ; n = 12
    ; I = P * r * n
    ; I
    ; exit