请参考链接：https://www.cnblogs.com/wangqiguo/p/5793448.html
diff命令单中模式
1. normal模式
diff file1.txt file2.txt
2. context模式
diff file1.txt file2.txt -c
3. Unified模式
diff file1.txt file2.txt -u
linux diff命令详解
原文：https://www.cnblogs.com/faberbeta/p/13235969.html
