1.每月最後一天的判斷

一、shell實現

[root@localhost test2]# vi month_lastday.sh
#/bin/bash
case $1 in
1|3|5|7|8|10|12) echo last_day=31 ;;
4|6|9|11)        echo last_day=30 ;;
2)               echo last_day=28 ;;
*)               echo "ERROR!" ;;
esac
[root@localhost test2]# chmod 755 month_lastday.sh
[root@localhost test2]# ./month_lastday.sh 1
last_day=31
[root@localhost test2]# ./month_lastday.sh 2
last_day=28
[root@localhost test2]# ./month_lastday.sh 4
last_day=30
[root@localhost test2]# ./month_lastday.sh 55
ERROR!