在Linux环境下，实现文本单词的替换并通过Makefile实现自动编译。-Open a txt format file as input.

　 You can create a simple testing file in English by yourself.

　 Read each line in the file and do the following items at same

time(case sensitivity).

　　　a) change all "we" to "you"

　　　b) change all "you" to "we"

　　　c) change all "We" to "You"

　　　d) change all "You" to "We"

　　　e) change all "WE" to "YOU"

　　　f) change all "YOU" to "WE"

　 And save the changed lines into a new file.