zlingh

摘要： tr,awk,sed 一：tr 1.大小写转换 cat file | tr [a-z] [A-Z] > new_file（大写 --> 小写） cat file | tr [A-Z] [a-z] > new_file 2.删除空行 cat file | tr -s "\n" > new_file 二 阅读全文