Reset the contents and settings all iOS-simulators

With Xcode 6, you can use the simctl command line utility:

xcrun simctl erase <device UDID>

With Xcode 7, you can erase all at once with:

xcrun simctl erase all

With Xcode 10:

#!/usr/bin/env sh

xcrun simctl shutdown all
xcrun simctl erase all

Based on the the answer from Jeremy Huddleston Sequoia I wrote a shell script that will reset all simulators.

For Xcode 7 you can use:

#!/bin/sh

instruments -s devices \
| grep "(\d[.0-9]\+) \[[0-9A-F]\{8\}-[0-9A-F]\{4\}-[0-9A-F]\{4\}-[0-9A-F]\{4\}-[0-9A-F]\{12\}\]" \
| grep -o "[0-9A-F]\{8\}-[0-9A-F]\{4\}-[0-9A-F]\{4\}-[0-9A-F]\{4\}-[0-9A-F]\{12\}" \
| while read -r line ; do
    echo "Reseting Simulator with UDID: $line"
    xcrun simctl erase $line
done

For previous versions use:

#!/bin/sh

instruments -s devices \
 | grep Simulator \
 | grep -o "[0-9A-F]\{8\}-[0-9A-F]\{4\}-[0-9A-F]\{4\}-[0-9A-F]\{4\}-[0-9A-F]\{12\}" \
 | while read -r line ; do
    echo "Reseting Simulator with UDID: $line"
    xcrun simctl erase $line
done