Bash Ripple Effect: Redirect Ledger

Redirection is how terminal output becomes durable evidence. This lesson trains the difference between creating a file with > and appending to the same file with >>.

echo 'start' > ledger.txt
echo 'next' >> ledger.txt
cat ledger.txt

After both writes, the ledger should contain both lines in sequence:

start
next

A lot of operational debugging depends on persistent traces. If you overwrite when you intended to append, you lose chronology and make incidents harder to reconstruct.

• Using > repeatedly and deleting earlier lines by accident.
• Appending to the wrong filename.
• Forgetting to validate file contents after writes.

Create a three-line timeline:

echo 'step-1' > timeline.txt
echo 'step-2' >> timeline.txt
echo 'step-3' >> timeline.txt
cat timeline.txt

This is the same pattern used for lightweight run logs and manual audit trails.