shell版本的万年历

刚知道代码区块的用法《pre》和《/pre》夹住想打的内容纪念一下

---

echo "please write year and month by twice!"
 read y
 read m
 if [[ $(($y%4)) -eq 0 && $(($y%100)) != 0 ]] || [ $(($y%400)) == 0 ]
 then
 ry=1
 else
 ry=0
 fi
 let fd=5*${y}/4+${y}%4-${y}/100+${y}/400
 echo " ============================"
 echo -e " Year${y} Month${m}\n Sun Mon Tue Wed Thr Fri Sat"
 days=(31 28 31 30 31 30 31 31 30 31 30 31)
 if [ ${ry} -eq 1 ]
 then
 days[1]=28
 fi
 i=0 d=0
 while [ ${i} -lt $((${m}-1)) ]
 do
 let d=${d}+${days[${i}]}
 let i++
 done
 fdy=$(((${d}+${fd})%7))
 day=1
 i=1
 while [ $i -le $fdy ]
 do
 printf " "
 let i++
 done
 while [ ${day} -le ${days[$((${m}-1))]} ]
 do
 printf "%4d" "${day}"
 let ca=$day+$fdy
 cb=$(($ca%7))
 if [ $cb -eq 0 ]
 then
 printf "\n"
 fi
 let day++
 done
 printf "\n"
 echo " ============================"