This verbosity makes me happy

Today I learned how to create aliases in PowerShell. I’m switching from Mac to Windows, and I want the terminal in VS Code to do what I want.

No terminal will work for me until it interprets gs as git status. I type that compulsively.

In bash, setting that up looks like this:

alias gs='git status'

But in PowerShell, aliases can only refer to single words. No parameters. Wat.

You can make a function with the whole command in it, and then set an alias to that function.

Function GitStatus { git status }
Set-Alias gs GitStatus

The first time I did this it felt kinda silly. But then the second time …

Function CommitDangit { 
    git add .
    git commit -m "temp" 
Set-Alias c CommitDangit

This alias c makes a crappy commit as quickly as possible. I use it when live coding, to make insta-savepoints when stuff works. (I’m a bit compulsive about committing, too. Just commit, dangit!)

The PowerShell syntax requires a long name for my command before I give it a short one. This is more expressive than the bash:

alias c='git add . && git commit -m "temp"'

My CommitDangit function is named for readability, plus a tiny alias for fast typing.

This is a win. I like it more than the bash syntax. PowerShell is a more modern scripting language, and it shows.

Bonus: in bash I put those aliases in a file like .bashrc or .bash_profile or sometimes another one, it depends. In PowerShell, I put the aliases in a file referenced by $profile. Edit it with: code $profile, no figuring out which file it is.

Next: reload the $profile in an existing window with . $profile

Cropping a bunch of pictures to the same dimensions

Ah, command line tools, they’re so fast. And so easy to use on a Mac.

Given a bunch of image files in the same dimensions, that you want to crop to a fixed portion of the image:

1) Install imagemagick

brew install imagemagick

2) put all the images in a directory by themselves, and cd to that directory in the terminal

3) check the size of one of them using an imagemagick command-line utility:

identify IMG_1400.jpg
IMG_1400.jpg JPEG 960x1280 960×1280+0+0 8-bit sRGB 434KB 0.000u 0:00.000

Oh look, that one has a width of 960 and a height of 1280.

4) crop one of them, look at it, tweak the numbers, repeat until you get the dimensions right:

convert IMG_1400.jpg -crop 750x590+60+320 +repage test.jpg

Convert takes an input file, some processing instructions, and an output file. Here, I’m telling it to crop the image to this geometry (widthxheight+xoffset+yoffset), and then make the output size match what we just cropped it to.

The geometry works like this: move down by the y offset and to the right by the x offset. From this point, keep the portion below and to the right that is as wide as width and as tall as height.

5) Create an output directory.

mkdir output

6) Figure out how to list all your input files. Mine are all named IMG_xxxx.jpg so I can list them like this:

ls IMG_*.jpgIMG_1375.jpg IMG_1380.jpg IMG_1385.jpg

7) Tell bash to process them all:[1]

for file in `ls IMG*.jpg`
echo $file
convert $file  -crop
750x590+60+320 +repage output/$file

8) Find the results in your output directory, with the same names as the originals.

[1] in one line:
for file in `ls IMG*.jpg`;> do echo $file; convert $file  -crop 7750x590+60+320 +repage out/$file; done