Kaushik Gopal on tip - Kaushik Gopal's Website

Go with monthly AI subscriptions friends

Sun, 16 Nov 2025 18:46:05 GMT

Go with monthly AI subscriptions friends

I can’t remember where I read this tip, but given how fast the AI lab models move, it’s smarter to stick with a monthly plan instead of locking into an annual one, even if the annual price looks more attractive.

I hit a DI issue on Android and was too lazy to debug it myself, so I pointed two models at it. GPT Codex gave me the cleanest, correct fix. Claude Sonnet 4.5 found a fix, but it wasn’t idiomatic and was pretty aggressive with the changes.

A month ago, I wouldn’t have bothered with anything other than the Claude models for coding. Today, Codex clearly feels ahead. Google is about to ship its next Gemini model and, from what I’m hearing, it’s going to be absurdly good.

In these wonderfully unstable times, monthly subscriptions are the way to go.

How to make the iPhone Continuity Camera work properly in Chrome

Thu, 12 Dec 2024 07:00:00 GMT

I use a pixel as my primary android phone. But as a mobile developer, I also keep an iPhone handy for those times I need to test how an app works on iOS (especially if it’s not available on Android¹).

But my iPhone doesn’t sit in a drawer unused. It doubles up as my webcam when not being used as a phone. This is possible because I use macOS for my primary desktop needs, and this wonderful feature it enables called “Continuity Camera”. I’ve removed a webcam from my setup thanks to this, and the camera actually works much better than most webcams out there today.

But there’s one really annoying thing about this setup. It won’t be recognized in Google Meet when using a chromium browser. Searching on Reddit points out that this is a bizzarre known security requirement for chromium browsers alone.

Your iPhone needs:

to be in landscape mode (so don’t have portrait lock on)
have the screen turned off
to be locked
motionless (so won’t work if handheld)
and have an unobstructed camera

wut 😵‍💫

But works like a charm. So if you run into this issue, fix those things and it’ll all work like a charm.

thinking about you Flighty. ↩︎

Pick the right JDK for Android Studio

Wed, 06 Mar 2024 08:00:00 GMT

If Android developers don’t setup the JDK correctly, you’ll be greeted with nasty errors like this:

Check your module classpath error

Cannot access 'java.lang.constant.Constable'
which is a supertype of 'java.lang.Class'.
Check your module classpath for missing or conflicting dependencies

Your app might compile fine but the IDE will keep surfacing pesky errors. This is because Android developers have a variety of ways to setup the JDK for your development environment. Too many.

On episode #249 of Fragmented we discussed the numerous JDK options and what they’re used for. Google now has an excellent developer doc for this.¹

Courtesy: Android Developer docs

If you don’t have time to catch up on all the valuable content above, here’s the takeaways:

1. Use the JDK that comes with Android Studio #

JBR² is battle tested with Android Studio and includes enhancements for running Android Studio well. To use it as your SDK, switch your Gradle JDK to JBR:

how to set jbr as your gradle jdk

Do a File > Invalidate Caches after this…

mother of all fixes

2. Match your`JAVA_HOME` with the Gradle JDK #

The Gradle JDK from Step 1 is used to compile your app from Android Studio. If you use the command line to build your app on the other hand, the JDK from your $JAVA_HOME³ is used.

If both of these don’t match, you can have multiple gradle daemons running around. Make sure to match the two.

# ~/.zshenv
export JAVA_HOME=$HOME/Applications/Android\ Studio.app/Contents/jbr/Contents/Home

If you’re not sure where the jbr-jdk is located:

This is the way.

no seriously, it’s really good. ↩︎
JetBrains Runtime ↩︎
…if you haven’t customized your environment too much. It’s a little more involved. ↩︎

letter.kau.sh – 2024 Mar

Fri, 01 Mar 2024 08:00:00 GMT

Welcome to the third installment of my newsletter. Your support as always means everything to me.

Let’s dive in.

What I’m watching, listening, reading #

[video] You’re Not Forgetful: My System for Memorizing Everything ###

Most people think they have a terrible memory. I know I did. This video by a YouTuber doctor challenged me to rethink that. I haven’t noticed a change in my memory’s capacity, but I’ve learned how to remember more.

[video] Apple TV+ Masters of the Air ###

Exceptionally shot. Solid 3.5 rating and worth the watch. Apple TV+ has been killing it.

[music video] Sample Breakdown: Daft Punk - Discovery ###

Sampling is the art of reusing a portion of a sound recording in another recording. It’s had a complicated history, especially with music licensing concerns and whatnot. Young Guru (Jay-Z’s tour D.J) has a good video explaining this.

But to fully appreciate sampling as an art, it’s not enough to hear the music; you have to visually “see” it. See watch Daft Punk do their magic now.

[audio book] Leadership Strategy and Tactics ###

I’ve been looking for good reads on leadership and this book by an ex-Navy seal came recommended. I have qualms with the narrator’s voice but I must say this was a good book with apt analogies.

Tips #

🚫 Apple Music ##

I use bluetooth headphones with my Mac and it drives me 🦇 💩 🍌 😡 every time I hit the play/pause button and see this window:

I don’t use Apple Music. I don’t want it to open every time. I’d love to disable it. Heck, I’d love to uninstall it altogether. Sadly, Apple doesn’t allow you to do this. No worries, noTunes has got your back:

brew install --cask notunes

A minor yet significant annoyance, zapped away.

New font - CommitMono ##

Readers of my blog know I’m obsessed with monospaced fonts. For my daily programming, I used a custom version of IBM Plex Mono and now more often San Francisco Mono ¹. I’m weary of using SF Mono though because of Apple’s restrictive licensing.

Imagine my happiness finding a new worthy contender - CommitMono. I admire the Danish creator’s philosophy around it:

There are better ways to design than putting a big effort into making something look special. Special is generally less useful than normal, and less rewarding in the long term. Special things demand attention for the wrong reasons, interrupting potentially good atmosphere with their awkward presence.

— Jasper Morrison, Super Normal Manifesto

There’s an option to customize it and you bet I did…

I do wish there was an alternative version of “r” with the extender at the baseline. That would make it 🧑‍🍳 💋.

Signing off #

This was a tough month. A few of my colleagues and friends who I deeply admire were let go. Turbulent times in tech :/.

Thank you once again for your support and readership. Your feedback is always welcome.

Until the next one.

which comes baked in with the Mac ↩︎

Option ⌥ key for shortcuts vs special characters

Sun, 04 Feb 2024 08:00:00 GMT

Ever tried using the option key (⌥) with another character as a keyboard shortcut in a macOS app?

For example, in Obsidian I use ⌥ r to replace templates in the active file; or ⌥ a to archive completed tasks for the day.

Using the default English > U.S. keyboard (or ABC) types special characters in your app like å or ® vs executing your app shortcuts. It’s frustrating.

If you’re heavy keyboard shortcut or a programmer wanting to use more keyboard shortcuts in your IDE like me, you’ll derive more use from ⌥ being used as a keyboard shortcut modifier.

Solution 1 ✗ ##

I’m not one to shy away from keyboard hacking. So I tried Karabiner to force remap the ⌥ keystroke when typed with another character, sending it directly to the application. That didn’t work.

I then pulled out my trusty Keyboard Maestro which is the tool I fall back to when all else fails. Nope, macOS seems to hijack these keystrokes at a deeper level.¹

Solution 2 ~ ##

There’s a quicker solution² – pick a different keyboard. A lot of online posts specifically recommend a “Unicode Hex Input” keyboard.

You can start using ⌥ a without å showing up, no sweat and the keyboard shortcuts work. The Unicode Hex Input keyboard is additionally cool cause it allows typing out unicode characters with their full code. Here’s an example: hold the ⌥ key and type 03c0 to see what you get.³

Problem solved? Not completely.

Open a program like iA writer⁴ or Arc and try using the keyboard shortcut ⌥ ⇧ → or ⌥ ⇧ ←. These basic macOS wide shortcuts should select the next/previous word respectively. Those no longer work. Let’s see if there’s any other options in there?

The selection shortcut start working in some apps but not all of them. Sigh. The search continues.

Solution 3 ✓ ##

After scouring forums, apple support threads, reddit etc. I finally found a solution that works.

You’ll need to create a custom keyboard and provide it as an Input source to the Mac (as you saw in earlier screenshots). You can use a program like Ukelele or this online tool that someone kindly created for free.

Alternatively, download the keyboard I made called “US Plain” and copy it over to your ~/Library/Keyboard Layouts directory. Log out of the mac and log in again. When you go to add a keyboard in the Input Sources menu, you’ll now find your keyboard under “Others”.

This solution reliably resolves all issues.

probably redirecting control character codes differently 🤷🏽. ↩︎
one would incorrectly assume. ↩︎
π ↩︎
my favorite macOS app for writing. ↩︎

letter.kau.sh – 2024 Feb

Thu, 01 Feb 2024 20:00:00 GMT

Welcome to the second installment of my newsletter. Your support means the world to me.

I’ve been told the key to building an audience is consistency. I’m committing to this idea by releasing my letter on the first day of each month. This way, you’ll always know when to look out for a new letter.

Let’s dive in.

What I’m watching, listening, reading #

[podcast] What Now? – Trevor Noah’s standup is good but he’s an even better interview host. His “Between the Scenes” segments are some of my favorite. His new podcast is really good so far.
[tv] Slow Horses – Just finished Season 1 and I’m giddy that there are two additional seasons waiting for me. The best feeling.
[tv] Blue Eye Samurai – I’ve swooned about this show before but I’ll promote it again any chance I get. It’s the best thing I watched in 2023.
[video] Where are U Now | Diary of a Song – Yes, it’s the one you’re thinking of, and yes it’s Beiber, but this video is specifically around how Diplo & Skrillex collaborated to make the song. I’ve got a bunch of these to share, so stay tuned.

Tech Tips #

Making use of the `/tmp` directory ##

Courtesy: Alex Xu via Twitter

Are you aware that Unix-based systems, like macOS, offer a “hidden” /tmp directory that clears out every time you reboot?

I set it as my default download location for files that are momentarily needed like downloads, screenshots, or installation packages. There’s no need for a manual cleanup of these files as your next reboot will just wipe them clean.

Caveat: since this directory is world-writable, other user profiles on your device can access these files.

Hiding your macOS dock ##

The Dock is one of those macOS features that I never use and strangely, it can’t be disabled. Nicholas shared a workaround that effectively hides it:

defaults write com.apple.dock autohide-delay -int 60 && killall Dock

It’s been working like a charm.

From my blog #

Get to Inbox 0 with Gmail ###

I wrote this post excited to share my tips on taming an email inbox. I shared it with the author of the plugin mentioned. He was kind and gracious but told me that my post was vapid (without using those words). He’s right. I rushed that post in an excitement to get it out. I oversold with that title.

This is why I love the internet and am willing to look foolish. It means I’m learning. I’ve since been thinking about re-editing that post. The title should have just been - how I use Gmail.

Replace git-number with git aliases ###

I wanted to go on more about my simplify series and how pumped I am about a queue of posts I have in mind for this topic. But reason and restraint found me and I figured folks will find their way to it, in time.

But if you’re curious… dear newsletter reader (❤️) the ones I’m thinking of: “How I Obsidian”, “iTerm → Terminal & sane dotfiles”, “Fish → Zsh”, “VSCode + NeoVim → Jetbrains”, “KeyboardMaestro + Alfred + Pastebot + WorldClock widget + … → Raycast”

If there’s one that you’re eager to read, let me know.

Musings #

Programming for good ##

As a programmer, I’m always looking for opportunities to apply my skills to benefit society and perform my civic duty. The opportunities are there…

The San Francisco subway system still runs on 5 1/4-inch floppies.

By way of Jason Kotke

SF has the best software engineers in the world and they’re riding the very Munis that run on 5¼ floppies, all around San Francisco. Yet, there isn’t an obvious way to volunteer time to help improve these systems. 💡

Free stuff getting better over time ##

If you’re reading this letter on a browser, you’ll notice I’ve spruced the website up a lot. I’m going to write more about the numerous subtle features a casual reader might miss.

But every time I start to work on it, there’s this guilt of sinking time into the effort. But I’m writing this to remind future me: it’s ok. Working on Henry is meditative for me - low stakes programming that makes atleast one person happy (me).

There’s also something fulfilling about the idea of improving the work you give out for free, over time. How often can you say that about other free things in life? 🧘🏽

Resolutions & Goals #

[Tolerance in thinking] Platformer leaves Substack ##

Casey Newton on leaving substack. I thought this was a measured response and he went about it the right way. I was especially curious how he’d handle the usual questions around freedom of speech & tolerance in thinking. His FAQ at the end does a good job.

[Self care] Back to Weightlifting ##

My transformation from a 100kg (220 lbs) teenager to a 70kg (154 lbs) fit young adult was anything but easy. It wasn’t inspiration but severe back pain that drove me. An elderly chiropractor candidly remarked “you’re the youngest non-injured patient I’ve ever had in my career”. That scared the shit out of me cause that dude was old. I learnt then that the only activity I was consistent with is weightlifting (thankfully).

I’m aiming to regain my former fitness by starting simple. For now, I’m alternating between two full-body workouts that I found on this slapstick YouTube channel.

Next month, I’ll switch it up with a different set.

Signing off #

Thank you genuinely for subscribing or reading my letters. I’d love to always hear more from you.

What would you like to see more or less of — tech insights, programming chatter, personal stories?

I’m finding my way. I’d appreciate all the help.

Until the next one.

Toggle window snapping with Keyboard Maestro

Sun, 16 Jul 2023 19:22:07 GMT

Shopify CEO Tobi Lütke in a tweet last year mentioned why he uses the Rectangle app even through Raycast has some of these options already. Rectangle allows you to “toggle” the window to different positions.

I was inspired by this and wanted to be able to do the same. But in keeping with my theme to Simplify, I didn’t want to add a new tool to my arsenal.

Keyboard Maestro¹ to the rescue!

This set of macros allow you to toggle between a few states:

Toggle to the left ½ ¼ ⅔ of the screen (with the same shortcut)
Toggle to the right ½ ¼ ⅔ of the screen
Toggle full screen and back
Toggle to the center of the screen and back
Toggle vertically

Download the Keyboard Maestro Macro group here.

referral link ↩︎

Share your macOS audio with multiple multiple bluetooth headphones or Airpods

Sun, 29 Jan 2023 05:27:58 GMT

When I travel on airplanes, I prefer to download content onto my 14" Macbook¹ so I can watch it offline during the flight. When my wife travels with me, we like catching up on some of the shows that we like to watch together.

But we both have our own pair of Airpods that we’d like to use to listen to the audio together. In the wired headphones days, I’d carry a headphone splitter that we’d plug both of our wired headphones into.

Courtesy: Wikimedia

This blog post provides instructions for the equivalent solution in our wireless/bluetooth headphones world.

Software #

I’m going to use Rogue Amoeba’s excellent solution Loopback in the below instructions. I’m pretty sure you can also use Soundflower, the native “Audio MIDI setup” app or other solutions. But Loopback makes this ludicrously easy.

Step 1: Pair headphones to the Mac ##

Pair each of the headphones individually to the Mac (as you typically would).

After pairing the first set, you might have to disconnect them (temporarily) and proceed to pair the second set individually.

Step 2: Create a Virtual multi-output device ##

Create a new virtual device in Loopback ²

Step 3: Add both headphones to the output channel ##

Gen2-2023 is the bluetooth headphones I use in the below instructions. Add both headphones to the Output channels.

If you’re wondering how both headphones connect directly, chalk it to the wonders of the Mac. While the first headphones is connected, connect your second pair (without disconnecting the first) and they both should be connected.

You probably will still only hear the output from one of the headphones, but we’re almost there.

Step 4: Switch Mac audio to new virtual device ##

If you’re all aboard the Rogue Amoeba wagon, Soundsource is another app they maintain, that makes it trivially easy to switch audio sources. For someone who keeps switching workstations, podcasts etc. this is delightful software.

Step 5: Play & Enjoy ##

Loopback also allows you to control volumes separately which is a godsend when you have two picky people.

An iPad would probably be better but I remain a iPhone + Macboook only kind of guy. ↩︎
This would be a “Multi-Output device” in the Audio MIDI app but Loopback simplifies these distinctions. ↩︎

Keyboard Maestro as a Text Expander replacement

Wed, 27 Jul 2022 07:00:00 GMT

icon by Yoolk

If you’ve recently needed a text expander utility, might I suggest the trusty Keyboard Maestro.¹

I switched from TextExpander → Alfred quite some time back. Somewhat recently, I again switched from Alfred → KM for a couple of reasons:

1. One tool to rule them all ##

Between work & home, I use multiple computers these days. Having to sync + maintain each of these different utilities across multiple computers is becoming tedious.

Keyboard Maestro is a mainstay in my productivity toolbelt and isn’t going anywhere. Might as well double down on it for the things it does well.

2. Fixing app quirks ##

One of the big problems I found with utilities like Alfred is that the text expansion would activate too quickly. Consequently, the expansion wouldn’t work in certain apps (like VSCode).

With Keyboard Maestro though, you can add a micro delay,² ensuring the snippets work flawlessly everywhere.

You can also limit the scope to just a few apps if you’re worried this delay will slow you down in non-problematic apps.

3. Mix text expansion with other macros ##

Building on that, with Keyboard Maestro, you’re not limited to just text replacement.

You can execute full-fledged macros with your text expansion. Here’s an example of how I add checklists in Google Docs.³

Keyboard Maestro remains one of the most powerful utilities for the Mac.

Referral link ↩︎
I use 0.5s ↩︎
It puzzles me that they haven’t assigned a default keyboard shortcut for this already. ↩︎

Magic enter command for (fish/zsh) shell

Sat, 23 Jul 2022 19:50:31 GMT

Two of the most common commands I run when I cd into a directory are:

git status (which i do through git-number)
ls -lh (aliased automatically as ll through fish)

If this directory is not a git repo, then I usually am thinking of command 2.
If however it is a git repository then
- I’d like to know if any files have been changed in this directory and
- which ones specifically (which is command 1).

Wouldn’t it be nice if I could just hit the ↩ (enter key) and have this automatically happen?

Solution for fish users ##

If you’re using fish, I got you covered:

# filename: fish/conf.d/magic-enter.fish
function magic-enter-cmd --description "Issue git status or ls on hitting enter in a dir"
 set -l cmd ll
 set -l is_git_repository (fish -c "git rev-parse --is-inside-work-tree >&2" 2>| grep true) # Special variable indicating git.
 set -l in_root_folder (fish -c "git rev-parse --show-toplevel >&2" 2>| grep (pwd))
 set -l repo_has_changes (git status -s --ignore-submodules=dirty)

 if test -n "$is_git_repository"
 if test -n "$in_root_folder"
 if test -n "$repo_has_changes"
 set cmd git-number
 end
 end
 end

 echo $cmd
end

function magic-enter
 set -l cmd (commandline)
 if test -z "$cmd"
 commandline -r (magic-enter-cmd)
 commandline -f suppress-autosuggestion
 end
 commandline -f execute
end

bind \r magic-enter

Solution for zsh users ##

If you’re using zsh, I adapted the native solution like so:

# filename: magic-enter.plugin.zsh
# Default commands
: ${MAGIC_ENTER_GIT_COMMAND:="git-number"} # run when in a git repository
: ${MAGIC_ENTER_OTHER_COMMAND:="ll"} # run anywhere else

magic-enter() {
 # Only run MAGIC_ENTER commands when in PS1 and command line is empty
 # http://zsh.sourceforge.net/Doc/Release/Zsh-Line-Editor.html#User_002dDefined-Widgets
 if [[ -n "$BUFFER" || "$CONTEXT" != start ]]; then
 return
 fi


 is_git_repository=$(git rev-parse --is-inside-work-tree)
 in_repo_root_folder=$(git rev-parse --show-toplevel)
 repo_has_changes=$(git status -s --ignore-submodules=dirty)

 if [ "$is_git_repository" = true ] && [ "$in_repo_root_folder" = $PWD ] && [ ! -z "$repo_has_changes" ]; then
 BUFFER="$MAGIC_ENTER_GIT_COMMAND"
 else
 BUFFER="$MAGIC_ENTER_OTHER_COMMAND"
 fi
}

# Wrapper for the accept-line zle widget (run when pressing Enter)

# If the wrapper already exists don't redefine it
(( ! ${+functions[_magic-enter_accept-line]} )) || return 0

case "$widgets[accept-line]" in
 # Override the current accept-line widget, calling the old one
 user:*) zle -N _magic-enter_orig_accept-line "${widgets[accept-line]#user:}"
 function _magic-enter_accept-line() {
 magic-enter
 zle _magic-enter_orig_accept-line -- "$@"
 } ;;
 # If no user widget defined, call the original accept-line widget
 builtin) function _magic-enter_accept-line() {
 magic-enter
 zle .accept-line
 } ;;
esac

zle -N accept-line _magic-enter_accept-line

Remember to source this in your .zshrc:

source magic-enter.plugin.zsh

Revisions ###

Make a change to only check git status in a root folder.
Reddit /u/colemaker360 reminded me that the ^/dev/null redirect strategy is now deprecated with fish 3.
Redditor /u/jblondreddit pointed out that porcelain can be a slow.
Add solution for zsh users

Manipulating images & PDFs using CLI commands

Fri, 22 Jul 2022 03:40:45 GMT

Whenever I need to convert, merge, or combine images or PDF files, I pull out my Terminal and attempt doing it first with CLI (command line interface) commands. Over time I’ve built an arsenal of CLI commands that 9/10 times does the trick faster than any other program.

Prerequisites ####

Most of the image manipulation commands require imagemagick and the PDF ones require poppler. Both of which are just a homebrew install away for macOS:

# image utilities
brew install "imagemagick"

# pdf utilities
brew install "poppler"

Merging ##

Merge images horizontally/vertically ###

# convert ships with imagemagick

## horizontal
convert +append image_1.png image_2.png merged
## vertical
convert -append image_1.png image_2.png merged // vertical

# using montage
# slightly better as it maintains transparency within images

## horizontal
montage 0_index.png 1_post.png -background none -tile 2x1 -geometry +0+0 PNG32:out.png
## vertical
montage 0_index.png 1_post.png -background none -tile 1x2 -geometry +0+0 PNG32:out.png

Merge images and PDFs ###

# convert ships with imagemagick
convert 1.png 2.pdf merged.pdf

Merge PDFs ###

# pdfunite ships with poppler
pdfunite output-1.pdf output-2.pdf output-3.pdf merged-1-3.pdf
pdfunite output-4.pdf output-5.pdf merged-4-5.pdf

# using native tools that comes with the macOS
"/System/Library/Automator/Combine PDF Pages.action/Contents/Resources/join.py" -o merged.pdf source1.pdf source2.pdf

# using ghostscript [also works with encrypted PDFs]
gs -q -dNOPAUSE -dBATCH -sDEVICE=pdfwrite -sOutputFile=merged.pdf source1.pdf source2.pdf source3.pdf

Splitting ##

Split multi-page PDF into single page PDFs ###

# pdfseparate & pdfunite ship with poppler

# split input.pdf into output-1.pdf output-2.pdf ... etc.
pdfseparate input.pdf output-%d.pdf
# split input.pdf from page 2 till the end
pdfseparate -f 2 input.pdf output-%d.pdf

Replacing single pages in PDF ##

A common usecase is to swap out a single page in a pdf. poppler doesn’t have a readymade command for this, instead i just use pdfseparate + pdfunite for this:

# input has 10 pages; special has 3 pages
# replace pages 5,6,7 in input with special pages

pdfseparate input.pdf input-%d.pdf
pdfseparate special.pdf special-%d.pdf

# using fish shell
for i in (seq 1 4)
 pdfunite input-$i
end

Resizing/Compression ##

By % or boundary ###

# convert ships with imagemagick
convert -resize 60% src_img.png src_img_reduced.png
convert -resize 128x128 src_img.gif src_img_reduced.gif

Doesn’t overwrite
60% is good for documents
75% is acceptable image quality (though you probably want higher)

By keeping aspect ratio & max dimension ###

sips -Z 800 input.png --out output.png

# Z maintain aspect ratio
# 800 max height and width to be used

In directory ###

# resize all images in directory
for f in *.jpeg
do
 convert -resize 60% "$f" dest/src_img_reduced.png
done

Converting ##

DNG → JPG ###

# sips ships natively with macOS
sips -Z 3072 -s format jpeg input.dng --out output.jpg

# Z maintain aspect ratio
# -s format jpeg

Overwrites
Aggressively reduces

PNG → JPG ###

# sips ships natively with macOS
sips -s format png input.jpg --out output.jpeg

HEIC → JPG ###

# sips ships natively with macOS
sips -s format jpeg input.heic --out output.jpeg

PDF → JPG ###

# convert ships with imagemagick
convert -density 150 -quality 100 -flatten -sharpen 0x1.0 -trim input.pdf output.jpg
# 3rd page of pdf
convert input.pdf[2] output.jpg
# convert all pages (2 means 2 digits will show on page count)
convert input.pdf output-%02d.jpg

# pdftoppm ships with poppler
# output is a prefix
# 150 is DPI
pdftoppm -jpeg -r 150 input.pdf output

JPG → PDF ###

# convert ships with imagemagick
convert 1.jpg 2.jpg merged.pdf

JPG → (A4 paper size) PDF ###

convert -density 80 input.jpeg -background white \
 -page a4 # -page Letter
 output.pdf

JPG → PNG ###

# sips ships natively with macOS
sips -s format png input.jpg --out output.png

PNG → WEBP ###

# install webp utility
brew install webp

cwebp input.png -o output.webp
cwebp -q 75 input.png -o output.webp
# -q 75 refers to the compression rate.

SVG → WEBP ###

# convert ships with imagemagick
convert -background none -density 200 input.svg output.webp

SVG → PNG ###

# convert ships with imagemagick
convert -background none -density 1000 -resize 48x is_logo_location.svg is_logo_location.png

PNG → GIF ###

# convert ships with imagemagick
convert -delay 5 -loop 0 *.png output.gif

MOV/MP4 → GIF ###

# convert ships with imagemagick
mkdir frames
# mov or m4v
# ffmpeg -i input.mov -vf scale=320:-1,format=rgb8,format=rgb24 -r 10 frames/ffout%3d.png
ffmpeg -i input.mov -vf scale=320:-1 -r 10 frames/ffout%3d.png
convert -delay 8 -loop 0 frames/ffout*.png frames/output.gif

# scale [width in px]:-1
# r framerate

Manipulating ##

Remove transparency ###

# flattens png to a solid color
# mogrify ships with imagemagick
mogrify -background white -flatten input*.png

Get information from image ##

Is image transparent? ###

# identify ships with imagemagick
identify -format '%[channels]' foo.png

List image dimensions ###

identify -format '"%w %h' foo.png

I’ll keep adding more as I discover new use cases.

Remove Terminal.app from Alfred & Spotlight

Sun, 29 May 2022 07:00:00 GMT

I use iTerm as my terminal of choice.¹ It constantly annoys me when I use Alfred or Spotlight that the Terminal.app (native macOS) app also shows up in the search results.

This is especially annoying on new computers when Alfred hasn’t learnt my preferences as Terminal.app would show up first in the results.

Options ##

Quick googling shows two options:

Add a Spotlight comment alfred:ignore
Add the app to your Spotlight “privacy”

Option 1 is made a little complicated owing to the fact that you can’t add spotlight comments to native “Utilities” app on the Mac. I managed to do this but this option doesn’t work.

At first, Option 2 might also seem tricky since the file picker doesn’t allow you to pick Utilities apps again. But there’s an easy workaround:

Open Spotlight Preferences > Privacy Tab
Open new Finder window & search for “Terminal.app”
Drag Terminal.app search result to Privacy Tab on Spotlight preferences
type “Reload” in Alfred

Now, whenever I search for “Term”, I only see “iTerm” show up in my search results.

Video ##

Why I use iTerm is for another blog post. ↩︎

Hacking your keyboard with karabiner

Wed, 25 Dec 2019 07:00:00 GMT

Update

I’ve since come up with an easier way to maintain my rules. This post talks of some of the cool things you can do with Karabiner. But if you want a more maintainable way of customizing all this, read my other post instead.

tl;dr:

brew install yqrashawn/goku/goku
mkdir -p ~/.config && cd ~/.config
touch karabiner/karabiner.json
touch karabiner.edn
# update your edn file with a sample from here https://github.com/yqrashawn/GokuRakuJoudo/blob/master/tutorial.md
# or mine: https://gist.github.com/kaushikgopal/ff7a92bbc887e59699c804b59074a126
goku

Background #

I’ve been messing with mechanical keyboards recently.¹ There was one in particular which is a 60% layout that I fell in love with.

The trouble with 60% keyboards though is that they can be pretty constraining for some basic operations (like navigation). Notice there aren’t dedicated keys for the up/left/down/arrows.

Courtesy: Wikipedia

Given these constraints, you have to get a little creative with how you use a keyboard. I added a bunch of mods for the keyboard using the mechanical keyboard’s included software configurator. I liked these mods so much that I wanted to find a way to use these mods with any keyboard I use.

The easiest way I’ve found on the Mac to do this is using Karabiner. Karabiner intercepts every keystroke and allows you to send alternative signals.

For example, a common mod that a lot of programmers like to do is remap their Caps Lock key -> Escape. So if I tap the Caps Lock key, it instead emulates hitting the Escape key. You can do this pretty easily with Karabiner but it barely scratches the surface of Karabiner’s true power.

Complex modifications: ##

Where Karabiner will truly shine is when you want to do slightly more complex things: for example, take the case of navigation with 60% keyboards. While they don’t come with dedicated arrow keys you can emulate navigation in a pretty slick way (especiallly for us vim users).

Instead of moving my fingers all the way to the bottom right of my keyboard and aiming for the arrow keys what if I could just keep my fingers on my home row and navigate like so:

tap caps lock once -> Escape key
hold caps lock -> left_control
hold caps lock and press h -> left arrow
hold caps lock and press j -> down arrow
hold caps lock and press k -> up arrow
hold caps lock and press l -> right arrow

You can of course choose to map any key combo (for example right shift key + W/A/S/D). I chose H/J/K/L cause I’m a vim user and I love just using h/j/k/l to navigate anywhere on my Mac!

More Complex modifications: ##

Even that, just scratches the surface of what you can do with Karabiner. Another quick hack I use and love (as a programmer):

tap [ once -> type "["
hold [ and tap ] key once -> type "{"
tap ] once -> type "]"
hold ] and tap [ key once -> type "}"

If you’re a programmer this makes it easier to type curly braces without contorting your fingers and flaring up that RSI. For typing paranthesis there’s an even better one:

left_shift once -> type "("
hold left_shift -> use as a regular shift key modifier
right_shift once -> type ")"
hold right_shift -> used as a regular shift key modifier

But there’s more! ##

Apart from just modifying your key strokes, you can do advanced stuff like launching programs too. For example I typically switch between 3 applications pretty often: iTerm, Firefox, Things. With Karabiner, I use the same technique but switch programs pretty quickly:

hold o (for "open") + tap i -> launch "iTerm"
hold o + tap f -> launch "Firefox"
hold o + tap t -> launch "Things"
tap o once -> type "o"

This makes switching between apps almost instant. I don’t have to carefully Cmd + Tab, visually recognize each icon (adding one extra cognitive step 😁) and then launch it. This might seem frivolous at first but once you start using this quick open mode like functionality, it’s hard to go back to Cmd Tabbing.

Turbocharge mode (Karabiner + Keyboard Maestro) ###

I swear by Keyboard Maestro and use a lot of my macros pretty often. With Karabiner, I can map certain keyboard strokes to instead launch macros. For example, if I want to quickly Google something, I hold “o” then tap “g” -> this shows an input dialog to take in my text, then launches a new tab in firefox with a url to google prepoulated with my query.

hold "s" + tap g -> google for something on the web

This kind of usage in conjunction with Keyboard Maestro basically unleashes the power of your Mac.

How do I do this? #

Before you head to the races and start using Karabiner though there’s one caveat:

Use Goku to organize your Karabiner

See the problem with Karabiner is that if you want to start doing the tricks I mention above, you pretty much have to start meddling directly with this file called karabiner.json. Let’s just say json is not the most maintainable format for this kind of stuff.

After meddling with Karabiner for a few days, it was clearly getting unwieldy to maintain the json file. So on an exaseperated whim, I went searching for a way to make it easier to deal with Karabiner and found the wonderful Goku.

Enter Goku ##

Goku basically is a DSL where you can write a nice and condensed form of the same code you would otherwise wrangle up in your karabiner.json. You write the code in this special format called “extensible data notation” (edn). Goku then reads that edn format and generates the karabiner.json file for you.

For context:

my karabiner.json file currently has about 920 lines
my karabiner.edn file on the other hand has 140 lines (and most of it is liberal commenting and whitespace to combat edn’s terseness)

{:des "o-mode: quick open"
 :rules [:o-mode
 [:f [:open "/Applications/Firefox.app"] ]
 [:g [:km "0) Search Google"] ]
 [:i [:open "/Applications/iTerm.app"] ]
 [:q [:km "open: Quip"] ]
 [:t [:open "/Applications/Things3.app"] ]
]}

{:des "right cmd -> right ctrl"
 :rules [
 [:##right_command :right_control [:apl-usb-int :apl-bt :ap2] ]
 ]}

{:des "left shift once -> ("
 :rules [
 [:##left_shift :left_shift nil {:alone :!S9} ]
 ]}

{:des "right shift once -> )"
 :rules [
 [:##right_shift :right_shift nil {:alone :!S0} ]
 ]}

Speaking as a programmer the edn format is quite possibly the most terse, terrible format I’ve encountered. I gave a quick look at some of the examples and almost abandoned my Goku effort half way.

But after spending an 11 hour flight back home fiddling and learning how to use Goku, I’ve gotten a decent hang of the format and I admit it’s super mantainable.

How to read and use Goku ##

I’m not going to explain how to use Goku, but I’ll tell you what helped me pick it up:

Read this fantastic blog post by Nikita Voloboev once
Follow along then with the official tutorial as they explain the basics
Read the blog post from step 1 again, given you’re a little more familiar with the format
Read my karabiner.edn file

I spent a lot of time commenting my edn file with the hope of making it more readable, so hope that helps. I plan on making a youtube video at some point demoing all this but until that happens, hope this blog post is helpful.

Hit me up on Twitter for queries or comments. Super curious to see other creative hacks people can come up with this technique.

Example edns ###

Mechanical keyboards are a costly unhealthy obsession. I switch between an Anne Pro 2 and a TADA68 these days. ↩︎

Speed up your Android Studio

Mon, 19 Aug 2019 07:00:00 GMT

I use a 13" MacBook Pro at work these days. Android Studio frequently sent my machine into a tailspin.

Over time, I’ve had to tweak and update my AS settings to make AS work well on the 13". I figured I should post them here for posterity and the benefit of other AndroidDevs battling with deathly slow AS experiences.

I’m posting the abridged instructions and linking to the blog posts that led me to these settings, if you care for the details.

Switch to a local gradle distribution #

curl -s "https://get.sdkman.io" | bash # install sdkman

# install your preferred version of gradle

sdk install gradle 5.4.1
sdk default gradle 5.4.1

gradle --status

Once you have a local distribution of gradle installed, switch the “Gradle home:” setting in your Android Studio project to point to your local gradle distribution. You’ll have to do these for all your projects individually.

With this setup, when you run gradle on the command line or Android Studio, they’ll share the same gradle daemon instances.

☝️ also make sure the daemons from AS and your command line are compatible ##

Well almost. You also have to make sure you’re using the same JDK otherwise the gradle daemons will be incompatible.

# you have sdkman installed already
sdk install java 8.0.202-zulu # use java 8 preferably
sdk default java 8.0.202-zulu

sdk install kotlin # cause why not

Now point Android Studio to use this jdk like so:

💥 now we’re in business.

Disable any useless plugins or add-ons that you don’t need #

Don’t get carried away and disable everything here. It will hose your Android Studio. I know this cause I sure as hell tried.

The only plugins I have enabled are:

(Downloaded) IdeaVim
Android APK Suport
Android NDK Support
Git Integration (cause i like Intellij’s Differ)
Gradle
Groovy
Il8n for Java
Intellij Configuration Script
IntelliLang
Java Bytecode Decompiler
JUnit
Kotlin
Properties Support
Smali Support
YAML

Everything else is disabled. This crony from Bob’s Discount Action Bars apparently knows a thing or two about Android.

Tweak your `studio.vmoptions` file #

The official developer docs talk about configuring this properly.

tl;dr: in Android Studio head to “Help > Edit Custom VM Options…” and change it to the below:

#-Xms256m
#-Xmx2048m
-XX:ReservedCodeCacheSize=240m
-XX:+UseCompressedOops
-Dfile.encoding=UTF-8
-XX:+UseConcMarkSweepGC
-XX:SoftRefLRUPolicyMSPerMB=50
-Dsun.io.useCanonCaches=false
-Djava.net.preferIPv4Stack=true
-Djdk.http.auth.tunneling.disabledSchemes=""
-Djna.nosys=true
-Djna.boot.library.path=

-da
-Xverify:none

-XX:ErrorFile=$USER_HOME/java_error_in_studio_%p.log
-XX:HeapDumpPath=$USER_HOME/java_error_in_studio.hprof

# ###############################################
# custom settings from https://github.com/artem-zinnatullin/AndroidStudio-VM-Options/blob/master/studio.vmoptions
# ###############################################

# Runs JVM in Server mode with more optimizations and resources usage
# It may slow down the startup, but if you usually keep IDE running for few hours/days
# JVM may profile and optimize IDE better. Feel free to remove this flag.
-server

# Sets the initial size of the heap, default value is 256m
-Xms1G

# Max size of the memory allocation pool, default value is 1280m
-Xmx2G

# Sets the size of the allocated class metadata space that will trigger a GC the first time it is exceeded, default max value is 350m
-XX:MetaspaceSize=512m

Anything else you’ve come across that’s helped a lot? Hit me up on Twitter.

Updates since my post was originally published: ##

@TheSNAKY pointed me to an easier way to get to the Edit VM options.
@matthewcmckenna reminded me that using sdk man, using the /current path is better as you upgrade versions. I’ve changed the commands here to mark the default installation and then just point to that within the Android Studio screenshots

Useful resources and reference links: ##

Use paper towels more efficiently - shake and fold

Fri, 04 May 2012 07:00:00 GMT

I’m a little troubled that I love these kind of lifehack videos.

Kaushik Gopal on tip - Kaushik Gopal's Website

Go with monthly AI subscriptions friends

How to make the iPhone Continuity Camera work properly in Chrome

Pick the right JDK for Android Studio

1. Use the JDK that comes with Android Studio #

2. Match yourJAVA_HOME with the Gradle JDK #

letter.kau.sh – 2024 Mar

What I’m watching, listening, reading #

[video] You’re Not Forgetful: My System for Memorizing Everything ###

[video] Apple TV+ Masters of the Air ###

[music video] Sample Breakdown: Daft Punk - Discovery ###

[audio book] Leadership Strategy and Tactics ###

Tips #

🚫 Apple Music ##

New font - CommitMono ##

Signing off #

Option ⌥ key for shortcuts vs special characters

Solution 1 ✗ ##

Solution 2 ~ ##

Solution 3 ✓ ##

letter.kau.sh – 2024 Feb

What I’m watching, listening, reading #

Tech Tips #

Making use of the /tmp directory ##

Hiding your macOS dock ##

From my blog #

Get to Inbox 0 with Gmail ###

Replace git-number with git aliases ###

Musings #

Programming for good ##

Free stuff getting better over time ##

Resolutions & Goals #

[Tolerance in thinking] Platformer leaves Substack ##

[Self care] Back to Weightlifting ##

Signing off #

Toggle window snapping with Keyboard Maestro

Share your macOS audio with multiple multiple bluetooth headphones or Airpods

Software #

Step 1: Pair headphones to the Mac ##

Step 2: Create a Virtual multi-output device ##

Step 3: Add both headphones to the output channel ##

Step 4: Switch Mac audio to new virtual device ##

Step 5: Play & Enjoy ##

Keyboard Maestro as a Text Expander replacement

1. One tool to rule them all ##

2. Fixing app quirks ##

3. Mix text expansion with other macros ##

Magic enter command for (fish/zsh) shell

Solution for fish users ##

Solution for zsh users ##

Revisions ###

Manipulating images & PDFs using CLI commands

Prerequisites ####

Merging ##

Merge images horizontally/vertically ###

Merge images and PDFs ###

Merge PDFs ###

Splitting ##

Split multi-page PDF into single page PDFs ###

Replacing single pages in PDF ##

Resizing/Compression ##

By % or boundary ###

By keeping aspect ratio & max dimension ###

In directory ###

Converting ##

DNG → JPG ###

PNG → JPG ###

HEIC → JPG ###

PDF → JPG ###

JPG → PDF ###

JPG → (A4 paper size) PDF ###

JPG → PNG ###

PNG → WEBP ###

SVG → WEBP ###

SVG → PNG ###

PNG → GIF ###

MOV/MP4 → GIF ###

Manipulating ##

Remove transparency ###

Get information from image ##

2. Match your`JAVA_HOME` with the Gradle JDK #

Making use of the `/tmp` directory ##

Tweak your `studio.vmoptions` file #