http://www.cnblogs.com/xiangzi888/archive/2012/03/27/2420084.html
https://www.cnblogs.com/xiangzi888/p/4025549.html
How can I replace a string in a file(s)?
https://unix.stackexchange.com/questions/112023/how-can-i-replace-a-string-in-a-files/112024#112024
https://stackoverflow.com/questions/905144/sed-beginner-changing-all-occurrences-in-a-folder
https://stackoverflow.com/questions/11392478/how-to-replace-a-string-in-multiple-files-in-linux-command-line
http://brunolinux.com/02-The_Terminal/Find_and%20Replace_with_Sed.html
https://www.folkstalk.com/2012/01/sed-command-in-unix-examples.html
http://www.runoob.com/w3cnote/linux-findtoreplace.html
http://www.cnblogs.com/end/archive/2012/05/24/2517131.html
sed -i -- 's/foo/bar/g' *其实可以直接为sed -i 's/foo/bar/g' *, 这个表达式也可以在vim里面操作
find . -type f -exec sed -i.bak "s/foo/bar/g" {} \; 还未尝试
sed -i "s/原字符串/新字符串/g" `grep 原字符串 -rl 所在目录` 未尝试
bash programming
http://tldp.org/HOWTO/Bash-Prog-Intro-HOWTO.html#toc11
How to compare strings in Bash
https://stackoverflow.com/questions/2237080/how-to-compare-strings-in-bash
unix-quick-guide
https://www.tutorialspoint.com/unix/unix-quick-guide.htm