_until

来自「《Beginning Linux Programming》书的配置实例源代码。」· 代码 · 共 14 行

#!/bin/sh

until who | grep "$1" > /dev/null
do
  sleep 60
done

# Now ring the bell and announce the unexpected user.

echo -e \\a
echo "***** $1 has just logged in *****"

exit 0