A command line utility for changing your Slack status.

slackstatus.sh

#!/bin/bash

# Usage: slackstatus "My new status"

function slackstatus() {
	slacktoken=$SLACK_OAUTH_TOKEN
	apiurl="https://slack.com/api/users.profile.set?token="$slacktoken"&profile="
	emoji=":mag:"

	if [ $# -eq 0 ]
	  then
	    status=""
	    emoji=""
	  else
	    status="$@"
	fi

	curl --silent --data-urlencode "profile={\"status_text\":\"$status\",\"status_emoji\": \"$emoji\"}" $apiurl > /dev/null
	echo "Status changed to $status"
}
export -f slackstatus > /dev/null

Thanks to @samervin for inspiration.
This script uses Slack API to change status (https://api.slack.com/docs/presence-and-status). I use it to set my status to "Focusing" when I start a pomodoro-like app called Focus on my Mac.

To set this up.
You'll need to set your last name, as well as get a token from https://api.slack.com/docs/oauth-test-tokens

To use, type slackstatus . To reset your status (to just your last name), just type slackstatus with no arguments.