Appending: >>

You learned that > overwrites a file. When you want to add new lines at the end without destroying existing content, use >> (double arrow).

The pattern is: COMMAND >> FILE.

echo "Entry 1: docking complete" >> ship.log
echo "Entry 2: cargo loaded" >> ship.log
cat ship.log

Entry 1: docking complete
Entry 2: cargo loaded

Both lines are preserved. Each >> appends to the bottom.

> vs >>

If the file does not exist yet, both > and >> will create it. The difference only matters when the file already has content.

A common pattern is to use > once to start fresh, then >> to accumulate more data over time, like a station log that grows with each shift.

Mission: Shift Log Update

The outgoing watch officer recorded the launch sequence in mission.log. Your shift is starting and you need to update the record, then file a backup.

1. Add status: shields nominal to the end of mission.log without erasing the existing entry.
2. Add status: crew ready to the end of mission.log the same way.
3. Count the lines in mission.log to confirm it now holds three entries.
4. Create a folder called archive and copy mission.log into it under the name mission-backup.log.

Expected result

mission.log holds all three status lines, and archive/mission-backup.log is an identical backup:

status: launch sequence initiated
status: shields nominal
status: crew ready