#-------------------------------------
# Script: wait_for --- wait for a user to log in
# 用法: wait_for user [ sleeptime ]
#-------------------------------------
wait_for ( ) {
until who | grep "$1" > /dev/null
do
sleep ${2:-100}
done
}
wait_for clinton #Wait for clinton, check every 100 sec
wait_for obama 60 #Wait for obama, check every 60 sec
equal ( ) {
test "$1" -eq "$2" && return 0 || return 1
}
equal "$a" "$b" && echo "$a and $b are equal"
equal "$c" "$d" || echo "$c and $d are not equal"