TIL is my collection of daily learnings. Each entry is brief, technical, and lightly edited.
Vim Jump to Previous Occurrence
In Vim Normal mode, * searches forward for the next occurrence of word. But what goes back? ...
TIL
Print Python Function Definition With Getsource
If I’ve defined a function in the Python REPL, I can read its definition with inspect.getsource. ...
Python REPL Help
In the Python REPL, the help function provides a help message about its argument. ...
Jira Standup Mode
Jira recently launched ‘Standup Mode’ feature, and love it! ...
Kill MacOS Processes by Name
I have a cron job that opens a program every day at a certain time. How can I also close it with a cron job? ...
pbcopy, no cat
My friend Josh recently wrote about a common mistake using pbcopy, Apple’s pasteboard utility. ...
Pause Script Execution in Chrome
Anytime Chrome loads a webpage, you can pause script execution without a debugger. ...
Load a Dependency in the Node REPL
Exploring your JS dependencies locally is a great way to learn and experiment. Here’s how to load a dependency from your /node_modules directory into the Node REPL. $ node > cn = require('classnames') > cn("always", { never: false, sometimes: true }) 'always sometimes'
Filtering By Identity
I’m reading Functional-Light JavaScript by Kyle Simpson, and learning a lot! Today I learned about the functional programming utility known as ‘identity’. Identity is a unary function that simply returns its argument. A simple idea that can be powerfully applied, as JavaScript coerces the returned argument to boolean: > const identity = (arg) => arg > ["", false, "keep", null, undefined, "these"].filter(identity) [ 'keep', 'these' ] I’ve done something similar for years by filtering to boolean, or writing my own (I didn’t know it had this name) anonymous identity function. ...
Show How A File Is Ignored In Git
Today I solved a mystery: a file was being Git-ignored in a new project that didn’t have a .gitignore. Here’s me learning this by trying and failing to add it: $ git add destroy.sh The following paths are ignored by one of your .gitignore files: destroy.sh This output tells me some .gitignore is telling Git to ignore my script. Another way to confirm this is the check-ignore command: $ git check-ignore destroy.sh destroy.sh The output here is the match; a file named destroy.sh is indeed being ignored. But how? We can answer that question with the -v flag: ...