cd work
printf 'pwd=%s\n' "$(pwd)"
printf 'upper=%s\n' "$(cat f | tr a-z A-Z)"
ls *.txt | wc -l
( cd sub && pwd )
cat <<'EOF'
$HOME stays literal
EOF
cat missing 2>/dev/null >> log
cat f 2>/dev/null >> log
cat log
wc -l < file
for f in *; do printf 'entry=%s\n' "$f"; done
false || echo ok
false
echo $?
( cd sub && cd ../../other && pwd && cd ../work && pwd )
yes | head -n 2