我对Unix完全是新手。有人可以帮助我解决目录中包含文件列表的问题， 我想按如下所述以所需格式处理文件名
< Filenames present in directory >
AAAL_555A_ORANGE_F190404_D190408.TXT.freshfruits_20190422-115617
AAAL_555A_MANGO_F190404_D190408.TXT.freshfruits_20190422-120939
AAAL_555B_APPLE_F190404_D190408.TXT.freshfruits_20190422-121449
AAAL_555B_ORANGE_F190404_D190408.TXT.freshfruits_20190422-115617
AAAL_555B_Orange_F190404_D190408.TXT.freshfruits_20180422-115617
<After modification >
If 2nd string 555A and 3rd string is ORANGE or 2nd string 555A and 3rd string is Orange the filename should be BB_Orange_555a_date +'%Y%m%d'.txt
If 2nd string 555B and 3rd string is ORANGE or 2nd string 555A and 3rd string is Orange the filename should be BB_Orange_555b_date +'%Y%m%d'.txt
If 2nd string 555B and 3rd string is APPLE or 2nd string 555A and 3rd string is Apple the filename should be BB_Apple_555b_date +'%Y%m%d'.txt
If 2nd string 555A and 3rd string is MANGO or 2nd string 555A and 3rd string is Mango the filename should be BB_Mango_555a_date +'%Y%m%d'.txt
有人可以用Shell脚本帮助我吗