Install with brew install quackduck/tap/chanch or build from source with swift build in the root directory.
Chanch is a WiFi channel changer for macOS allowing complete control over channel
number and channel width
USAGE: chanch --status
chanch <channel-num> [--80 | --40 | --20]
ARGUMENTS:
<channel-num> The WiFi channel number to change to
OPTIONS:
--80/--40/--20 Channel width in MHz.
(Usually 80 for the 5GHz band and 20 for the 2GHz band)
--status Just print the current channel, don't change it.
-h, --help Show help information.
Chanch is useful when packet sniffing (for example, with wif). To discover channels to listen on, you can use the airport utility to run a network scan: /System/Library/PrivateFrameworks/Apple80211.framework/Versions/Current/Resources/airport -s
Why not just use airport, you ask? Essentially, it's because airport doesn't allow changing the channel width, so when you switch from a 2.4 GHz band channel to a 5 GHz band channel, you may still have the narrower 20 MHz width instead of the expected 80 MHz width. Here's a demo of this:
