# Install wait_on with Homebrew, MacPorts Provides shell scripts with access to kqueue(3). Version 1.1 via Homebrew; verified from local package data. ## Install ```sh sudo av install brew:wait_on ``` Additional install commands: ### macOS - Homebrew (100%): ```sh brew install wait_on ``` Evidence: local Homebrew formula metadata - MacPorts (94%): ```sh sudo port install wait_on ``` Evidence: MacPorts ports tree: sysutils/wait_on/Portfile from https://api.github.com/repos/macports/macports-ports/git/trees/master?recursive=1 ## Package facts - **Package key:** brew:wait_on - **Package manager:** Homebrew - **Package manager page:** - **Version:** 1.1 - **Source summary:** Provides shell scripts with access to kqueue(3) - **Homepage:** - **Upstream docs:** - **License:** BSD-4-Clause - **Source archive:** - **Generated:** 2026-07-08T18:08:21+00:00 ## Executables - wait_on (cli) - wait_on (alias) ## Build dependencies - bmake ## Install behavior - Post-install hook: not defined - Bottle: available on arm64_big_sur, arm64_monterey, arm64_sequoia, arm64_sonoma, arm64_tahoe, arm64_ventura, big_sur, catalina, monterey, sonoma, ventura ## Freshness - Page generated: 2026-07-08 - Package-manager version: 1.1 - Local data: ok - Upstream repository: https://www.freshports.org/sysutils/wait_on/ - info: No package-manager update timestamp was available. - info: Release/tag comparison is only available for GitHub repositories. ## Project history and usage `wait_on` is a small FreeBSD-oriented command that exposes file and directory change notifications to shell scripts. It lets scripts sleep until a watched path changes instead of polling in a loop. ### Project history The FreeBSD manual page gives the clearest project history: `wait_on` was written by Andrew Stevenson in January 2002 under FreeBSD 4.4. Its design is tied directly to kqueue, the BSD kernel event-notification facility that had recently made file, directory, and descriptor events available without busy polling. ### How it is used The command waits on one or more files or directories and exits when a requested event occurs. The manual gives examples such as watching a mailbox for writes, waiting for files to arrive in an incoming FTP directory, or using `-i` and `-t` so a script can tell which watched path changed or timed out. Internally, `wait_on` uses kqueue's vnode notifications, including events for writes, extension, deletion, renames, link-count changes, attribute changes, and revocation. That makes it a compact bridge between shell scripting and kernel event delivery on systems with kqueue. ### Why package nerds care This is a classic small Unix package: one command, one system primitive, and a clean scripting use case. It is historically interesting because it predates the later wave of cross-platform file-watcher tools and shows early BSD users solving shell automation without periodic `stat` polling. ### Timeline - January 2002: `wait_on` was written under FreeBSD 4.4 by Andrew Stevenson. - 2000s onward: the command remained useful as a shell-level wrapper around kqueue file and directory events. ### Related projects - The closest related primitive is kqueue itself. In the broader file-watching family, `wait_on` overlaps conceptually with inotify-based Linux tools and higher-level cross-platform watchers, but it stays intentionally close to the FreeBSD kernel interface. ### Sources - - - ## Security Notes generalized runtime or code generation signal. - **Geiger risk:** yellow / medium - generalized runtime or code generation signal ## Source Database Details - **Source Database:** Homebrew formula API - **Tap:** homebrew/core - **Full Name:** wait_on - **Version Scheme:** 0 - **Revision:** 0 - **Requirements:** macos - **Bottle Stable Root URL:** - **Deprecated:** no - **Disabled:** no - **Keg Only:** no - **URL Keys:** stable ## Other Package-Manager Records - MacPorts - wait_on: normalized package name match | MacPorts ports tree: sysutils/wait_on/Portfile from https://api.github.com/repos/macports/macports-ports/git/trees/master?recursive=1 ## Related links - [Secret-risk packages](https://www.automicvault.com/pkg/secret-risk-packages/) - Has protected-tool coverage, approval-gate, or non-low Geiger security signals. - [Terminal utility packages](https://www.automicvault.com/pkg/terminal-utilities/) - Matched terminal and command-line workflow metadata. - [Networking and protocol packages](https://www.automicvault.com/pkg/networking-protocol-tools/) - Matched network, protocol, or remote-service metadata. - [Homebrew utility packages](https://www.automicvault.com/pkg/brew-utility-packages/) - Matched Homebrew package provider. - [bmake](https://www.automicvault.com/pkg/brew/bmake/) - Build dependency declared by Homebrew. - [kqwait](https://www.automicvault.com/pkg/brew/kqwait/) - Shares av.db curated category or tags: cli, file-monitoring, kqueue, system. - [fsevent_watch](https://www.automicvault.com/pkg/brew/fsevent-watch/) - Shares av.db curated category or tags: cli, file-monitoring, system. - [fsevents-tools](https://www.automicvault.com/pkg/brew/fsevents-tools/) - Shares av.db curated category or tags: cli, file-monitoring, system. - [abduco](https://www.automicvault.com/pkg/brew/abduco/) - Shares av.db curated category or tags: cli, system. - [acl](https://www.automicvault.com/pkg/brew/acl/) - Shares av.db curated category or tags: cli, system. - [acpica](https://www.automicvault.com/pkg/brew/acpica/) - Shares av.db curated category or tags: cli, system. - [afio](https://www.automicvault.com/pkg/brew/afio/) - Shares av.db curated category or tags: cli, system. - [afsctool](https://www.automicvault.com/pkg/brew/afsctool/) - Shares av.db curated category or tags: cli, system. - [wait-on](https://www.automicvault.com/pkg/npm/wait-on/) - Same normalized package name appears in another local ecosystem. Shared terms: cli, system, wait, wait-on. - [wait-on](https://www.automicvault.com/pkg/npm/wait-on/) - Same normalized package name in another local ecosystem. ## Combined YAML source View the package source record on GitHub. [combined/wait_on.yml](https://github.com/automic-vault/db/blob/main/combined/wait_on.yml) ## Sources - Nucleus package database - Geiger risk classifier - package-page enrichment - curated package history - package version freshness - av.db category and tag curation - package relationship graph - external package-manager database matches - cross-ecosystem install command graph