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TC39 Advances Temporal to Stage 4 Alongside Several ECMAScript Proposals
TC39’s March 2026 meeting advanced eight ECMAScript proposals, including Temporal reaching Stage 4 and securing its place in the ECMAScript 2026 specification.
Like the unix which utility.
Finds the first instance of a specified executable in the PATH
environment variable. Does not cache the results, so hash -r is not
needed when the PATH changes.
const which = require('which')
// async usage
// rejects if not found
const resolved = await which('node')
// if nothrow option is used, returns null if not found
const resolvedOrNull = await which('node', { nothrow: true })
// sync usage
// throws if not found
const resolved = which.sync('node')
// if nothrow option is used, returns null if not found
const resolvedOrNull = which.sync('node', { nothrow: true })
// Pass options to override the PATH and PATHEXT environment vars.
await which('node', { path: someOtherPath, pathExt: somePathExt })
Just like the BSD which(1) binary but using node-which.
usage: node-which [-as] program ...
You can learn more about why the binary is node-which and not which
here
You may pass an options object as the second argument.
path: Use instead of the PATH environment variable.pathExt: Use instead of the PATHEXT environment variable.all: Return all matches, instead of just the first one. Note that
this means the function returns an array of strings instead of a
single string.The 'find-exec' package is similar to 'which' in that it helps you find the path to executables in your PATH. However, it has a different API and may offer additional options for searching.
The 'lookpath' package is another alternative to 'which' that provides a way to check for the existence of an executable in the system's PATH. It is designed to be a simple and lightweight solution with a promise-based API.
The 'command-exists' package is used to check if a given command-line tool is available on the system's PATH. Unlike 'which', it does not return the path to the executable but simply a boolean indicating whether the command exists.
FAQs
Like which(1) unix command. Find the first instance of an executable in the PATH.
The npm package which receives a total of 148,118,010 weekly downloads. As such, which popularity was classified as popular.
We found that which demonstrated a healthy version release cadence and project activity because the last version was released less than a year ago. It has 6 open source maintainers collaborating on the project.
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Security News
TC39’s March 2026 meeting advanced eight ECMAScript proposals, including Temporal reaching Stage 4 and securing its place in the ECMAScript 2026 specification.

Research
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Since January 31, 2026, we identified at least 72 additional malicious Open VSX extensions, including transitive GlassWorm loader extensions targeting developers.

Research
Six malicious Packagist packages posing as OphimCMS themes contain trojanized jQuery that exfiltrates URLs, injects ads, and loads FUNNULL-linked redirects.